| Diagnosis and Testing Refer to Wiring Diagrams Section 412-02 (-03), for schematic and connector information. Special Tool(s) | | Terminal Probe Kit 418-S035 | General Equipment Digital Multimeter (compatible with K-type thermocouple) Thermometer - Fluke 80 PK-8 (FSE number 260 4102 001 07) Worldwide Diagnostic System (WDS) Refrigerant center Diagnosis and Testing - VERIFY the customers concern.
- Visually CHECK for any obvious mechanical or electrical damage.
Visual Inspection | Mechanical | Electrical | - Refrigerant lines
- Condenser core
- Drive belt
- Coolant level
- Coolant hose(s)
- A/C compressor
| - Fuses
- Wiring harness
- Connector
| - RECTIFY any obvious causes for a concern found during the visual inspection before performing any further tests. CHECK the operation of the system.
- If the concern persists after the visual inspection, PERFORM a fault diagnosis on the electronic engine management with WDS and RECTIFY any displayed faults in accordance with the displayed fault description. CHECK the operation of the system.
- For vehicles with no stored faults, PROCEED in accordance with the Symptom Chart according to the fault symptom.
- Following checking or elimination of the fault and after completion of operations, the fault memories of all vehicle modules must be READ OUT and any stored faults must be DELETED. READ OUT all fault memories again following a road test.
Refrigerant Circuit - Quick Check WARNING:The air conditioning system is filled with refrigerant R134a. Observe "Health and Safety Precautions". For further information
REFER to: Health and Safety Precautions (100-00 General Information, Description and Operation).
Refrigerant circuit check WARNING:Under certain circumstances, refrigerant lines and A/C components may be extremely hot or cold. Exercising care, touch the refrigerant lines or A/C components in order to check this. Failure to follow these instructions may result in personal injury. - The refrigerant line from the refrigerant compressor to the condenser must be hot.
- The refrigerant line from the A/C condenser to the fixed orifice tube must be warm, but not so hot as the refrigerant line mentioned above.
- Determine the difference in temperature upstream and downstream of the A/C condenser by measuring the temperatures. Depending on the ambient temperature, the temperature difference should be more than 20°. If the temperature difference is less, check the condenser for contamination or damage to the fins as well as operation of the radiator fans.
- The refrigerant line between the fixed orifice tube and the evaporator must be cold from the point where the fixed orifice tube is installed. Depending on the weather, the refrigerant line may also have ice on its surface.
- The refrigerant line between the evaporator and the A/C compressor including the dehydrator must be cold.
Evaporator outlet temperature test To test the power of the A/C system, the temperature of the evaporator outlet line must be measured. To do this, the following preconditions must be met: - Open all windows.
- Set the air distribution to the defrost/dashboard position and open all the ventilation nozzles.
- DO NOT switch on recirculated air.
- Select lowest blower switch setting.
- Select lowest temperature setting.
NOTE:The temperature measurement cannot be done with a thermometer which makes no contact. False measurements may arise as a result of surface reflections. Connect the temperature sensor (Fluke 80 PK-8) to the outlet side of the evaporator. The temperature sensor must be positioned as closely as possible to the evaporator. Connect the temperature sensor to the multimeter. Start the engine and allow it to run at idle speed for several minutes. Switch on the A/C. After three minutes, measure the surface temperature of the evaporator outlet line. If the temperature measured is 2° C or lower, the A/C system is OK. If the temperature is higher, the A/C system may be under-filled. For further information
REFER to: Air Conditioning (A/C) System Recovery, Evacuation and Charging (412-00 Climate Control System - General Information, General Procedures).
Frequent faults and their causes If the customer expresses concern about insufficient cooling performance, ensure that the temperature control is working properly. - No or poor cooling performance:
- Blockage or narrowing of a refrigerant line or in the dehydrator: The location of the blockage or narrowing can easily be located by temperature comparisons at the refrigerant lines and the dehydrator. The blockage or restriction is located at the point where the temperature difference is identified. Note: A difference in temperature around the fixed orifice tube is normal. Once the blockage or restriction has been located, check and if necessary renew the relevant component. - Cooling power suddenly deteriorates (returns to normal after the compressor has been switched off for about 5 minutes):
- The cause is an iced-up fixed orifice tube because of moisture in the refrigerant circuit. In order to ensure that moisture is completely removed from the refrigerant circuit, the dehydrator should be renewed and the evacuation time should be extended to 2-3 hours. For further information REFER to: Suction Accumulator (412-03 Air Conditioning, Removal and Installation), Air Conditioning (A/C) System Recovery, Evacuation and Charging (412-00 Climate Control System - General Information, General Procedures). Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | Temperature control faulty / inoperative | * Fuse(s) * Circuit(s) * Heater/air conditioning control assembly * Heater control valve * Cooling system * Powertrain control module (PCM) * instrument Cluster | * | | Blower faulty/inoperative | * Fuse(s) * Circuit(s) * Blower * Blower switch * Blower resistor assembly | * | | Blower running continuously | * Circuit(s) * Blower switch | * | | Air conditioning inoperative (blower and heater OK) | * Fuse(s) * Circuit(s) * Air conditioning clutch * A/C clutch diode * A/C clutch relay * A/C relay * Refrigerant low-pressure switch * Refrigerant high-pressure switch * Air conditioning control assembly * Powertrain control module (PCM) * Quantity of refrigerant | * | | Inadequate A/C output | * Engine cooling fans * Condenser core * Refrigerant circuit * Quantity of refrigerant * Refrigerant line * Accumulator/dehydrator * Air Conditioning (A/C) Compressor * Fixed orifice tube | * CHECK cooling fans with WDS. * CHECK refrigerant circuit. | | Malfunction of the air recirculation flap - vehicles with A/C (heater and A/C OK) | * Circuit(s) * Air flap actuator * Air conditioning control assembly | * | | Condensed water from the air conditioning system in the footwell | * Outlet line * Rubber grommet | * CHECK condition of the outlet line and the rubber grommet and REPAIR if necessary. | System checks | PINPOINT TEST A : TEMPERATURE CONTROL FAULTY / INOPERATIVE | NOTE:The heater control valve reacts with delay to changes to the temperature settings. | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: DETERMINE THE FAULT CONDITION | | | 1 Ignition switch in position III. | | | 2 Run the engine until the temperature gauge indicates "NORMAL". | | | 3 Check operation of heater. | | | Does the heater continuously supply cold air? Yes No | | A2: CHECK HEATER CONTROL VALVE | WARNING:Never perform operations on the heater control valve before the heater control valve has cooled to ambient temperature. Failure to follow this instruction may result in personal injury. | | | 1 Set the temperature control to medium temperature. | | | 2 Check whether the heater control valve pulsates. | | | Is the heater control valve pulsating? Yes CHECK the coolant hoses for correct routing. BLEED the cooling system if necessary. If the cooling system is OK, RENEW the heater control valve. CHECK the operation of the system. No | | A3: CHECK THE VOLTAGE AT THE HEATER CONTROL VALVE | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C95 from heater control valve. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater control valve, connector C95, pin 1, circuit 14-CA82 (VT/BK), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 14-CA82 (VT/BK) between the heater control valve and soldered connection S13 using the Wiring Diagrams. CHECK the operation of the system. | | A4: CHECK HEATER CONTROL VALVE | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance at the heater control valve, connector C95, between pin 1 and pin 2, component side. | | | Is a resistance of 10-25 Ohm measured? Yes No RENEW the heater control valve. CHECK the operation of the system. | | A5: CHECK CONTROL VOLTAGE AT HEATER CONTROL VALVE | | | 1 Ignition switch in position III. 2 Run the engine at idle speed. | | | 3 Set the temperature control to medium temperature. | | | 4 Measure the voltage between the heater control valve, connector C95, pin 1, circuit 14-CA82 (VT/BK), wiring harness side and pin 2, circuit 31S-CA82 (BK/GN), wiring harness side. | | | Is an intermittent voltage between 0 V and battery voltage measured? Yes RENEW the heater control valve. CHECK the operation of the system. No | | A6: CHECK VOLTAGE AT HEATER/AIR CONDITIONING CONTROL ASSEMBLY | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C109 from heater/air conditioning control assembly. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater/air conditioning control assembly, connector C109, pin 8, circuit 14-CA83A (VT/OG), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and RECTIFY the open circuit between the heater/air conditioning control assembly and fuse F17 using the Wiring Diagrams. CHECK the operation of the system. | | A7: CHECK VOLTAGE AT HEATER/AIR CONDITIONING CONTROL ASSEMBLY | | | 1 Ignition switch in position 0. | | | 2 Measure the voltage between the heater/air conditioning control assembly, connector C109, pin 9, circuit 29-CA83 (OG/GN), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 29-CA83 (OG/GN) between the heater/air conditioning control module and soldered connection S16 using the Wiring Diagrams. CHECK the operation of the system. | | A8: CHECK THE GROUND CONNECTION OF THE HEATER/AIR CONDITIONING CONTROL ASSEMBLY | | | 1 Measure the resistance between the heater/air conditioning control assembly, connector C109, pin 2, circuit 91-CA83 (BK/RD), wiring harness side and ground. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 91-CA83 (BK/RD) between the heater/air conditioning control module and soldered connection S76 using the Wiring Diagrams. CHECK the operation of the system. | | A9: CHECK THE CIRCUIT BETWEEN THE HEATER/AIR CONDITIONING CONTROL ASSEMBLY AND THE HEATER CONTROL VALVE FOR OPEN CIRCUIT | | | 1 Measure the resistance between the heater/air conditioning control module, connector C109, pin 10, circuit 31S-CA82 (BK/GN), wiring harness side and the heater control valve, connector C95, pin 2, circuit 31S-CA82 (BK/GN), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes CHECK and if necessary RENEW the heater/air conditioning control assembly. CHECK the operation of the system. No LOCATE and REPAIR the break in circuit 31S-CA82 (BK/GN) between the heater/air conditioning control assembly and the heater control valve using the Wiring Diagrams. CHECK the operation of the system. | | A10: CHECK HEATER CONTROL VALVE | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C95 from heater control valve. | | | 3 Ignition switch in position III. 4 Run the engine at idle speed. | | | 5 Check operation of heater. | | | Does the heater become warm? Yes No CHECK the coolant hoses for correct routing. BLEED the cooling system if necessary. For further information
REFER to: Cooling System Draining, Filling and Bleeding (303-03 Engine Cooling - 1.3L Duratec-8V (Rocam)/1.6L Duratec-8V (Rocam), General Procedures).
If the cooling system is OK, remove the heater control valve and CHECK for blockages; RENEW if necessary. CHECK the operation of the system. | | A11: CHECK THE CIRCUIT BETWEEN THE HEATER/AIR CONDITIONING CONTROL ASSEMBLY AND THE HEATER CONTROL VALVE FOR A SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Connect connector C95 to heater control valve. | | | 3 Disconnect connector C109 from heater/air conditioning control assembly. | | | 4 Ignition switch in position III. 5 Run the engine at idle speed. | | | 6 Check operation of heater. | | | Does the heater become warm? Yes No LOCATE and REPAIR the short to ground in circuit 31S-CA82 (BK/GN) between the heater control valve and the heater/air conditioning control assembly with the aid of the Wiring Diagrams. CHECK the operation of the system. | | A12: CHECK THE SPEED SIGNAL AT THE HEATER/AIR CONDITIONING CONTROL ASSEMBLY | NOTE:If the speed signal at the heater/air conditioning control module is faulty, the heater cannot be set to "WARM". | | | NOTE:Perform measurement using WDS. Set the multimeter to "AC voltage" mode in order to measure the voltage. 1 Measure the voltage between the heater/air conditioning control assembly, connector C109, pin 6, circuit 8-GB10A (WH/BK), wiring harness side and ground. | | | Is a voltage of approx. 9 volts measured? Yes CHECK and if necessary RENEW the heater/air conditioning control assembly. CHECK the operation of the system. No | | A13: CHECK THE SIGNAL CABLE BETWEEN THE HEATER/AIR CONDITIONING CONTROL ASSEMBLY AND THE INSTRUMENT CLUSTER | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C105 from instrument cluster. | | | 3 Measure the resistance between the heater/air conditioning control assembly, connector C109, pin 6, circuit 8-GB10A (WH/BK), wiring harness side and the instrument cluster, connector C105, pin 28, circuit 8-GB10A (WH/BK), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes CHECK and if necessary RENEW the instrument cluster. CHECK the operation of the system. No LOCATE and RECTIFY open circuit in circuit 8-GB10A (WH/BK) between the heater/air conditioning control assembly and the instrument cluster with the aid of the Wiring Diagrams Binder. CHECK the operation of the system. | | PINPOINT TEST B : BLOWER FAULTY/INOPERATIVE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK ALL SPEED SETTINGS OF THE BLOWER MOTOR | | | 1 Ignition switch in position II. | | | 2 Switch the blower switch through all speed settings. | | | Is the blower motor inoperative in all the switch positions? Yes No - The blower motor is inoperative in switch positions 1, 2 and/or 3: GO to B9. - The blower motor is only inoperative in switch position 4: GO to B8. | | B2: CHECK FUSE F12 | | | 1 Ignition switch in position 0. | | | 2 CHECK Fuse F12 (CJB). | | | Is the fuse OK? Yes No Install a new fuse F12 (30 A). CHECK the operation of the system. If the fuse blows again, LOCATE and RECTIFY the short circuit using the Wiring Diagrams. | | B3: CHECK THE VOLTAGE SUPPLY AT FUSE F12 | | | 1 Connect Fuse F12 (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F12 (30 A) and ground. | | | Is battery voltage measured? Yes No RECTIFY the voltage supply to fuse F12 with the aid of the Wiring Diagrams. CHECK the operation of the system. | | B4: CHECK THE VOLTAGE AT THE BLOWER MOTOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C48 from blower motor. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the blower motor, connector C48, pin 1, circuit 14-CA1 (VT/BU), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in the circuit between the blower motor and fuse F12 using the Wiring Diagrams. CHECK the operation of the system. | | B5: CHECK THE GROUND CONNECTION OF THE BLOWER MOTOR | | | 1 Ignition switch in position 0. | | | 2 Set the blower switch to setting 4. | | | 3 Measure the resistance between the blower motor, connector C48, pin 2, circuit 31S-CA18 (BK/RD), wiring harness side and ground. | | | Is a resistance of less than 2 Ohm registered? Yes RENEW the blower motor. CHECK the operation of the system. No | | B6: CHECK THE CIRCUIT BETWEEN THE BLOWER MOTOR AND THE BLOWER SWITCH FOR OPEN CIRCUIT | | | 1 Disconnect connector C110 from blower switch. | | | 2 Measure the resistance between the blower motor, connector C48, pin 2, circuit 31S-CA18 (BK/RD), wiring harness side and the blower switch, connector C110, pin 6, circuit 31S-CA33 (BK/OG), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 31S-CA18 (BK/RD) between the blower motor and soldered connection S161 using the Wiring Diagrams. CHECK the operation of the system. | | B7: CHECK THE GROUND CONNECTION OF THE BLOWER SWITCH | | | 1 Measure the resistance between the blower switch, connector C110, pin 2, circuit 31-CA25 (BK), wiring harness side and ground. | | | Is a resistance of less than 2 Ohm registered? Yes RENEW the blower switch. CHECK the operation of the system. No LOCATE and RECTIFY the open circuit between the blower switch and ground connection G1 (vehicles with air conditioning: ground connection G3) with the aid of the Wiring Diagrams. CHECK the operation of the system. | | B8: CHECK THE CIRCUIT BETWEEN THE BLOWER MOTOR AND THE BLOWER SWITCH FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C110 from blower switch. | | | 3 Disconnect connector C48 from blower motor. | | | 4 Measure the resistance between the blower motor, connector C48, pin 2, circuit 31S-CA18 (BK/RD), wiring harness side and the blower switch, connector C110, pin 6, circuit 31S-CA33 (BK/OG), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes RENEW the blower switch. CHECK the operation of the system. No LOCATE and REPAIR the break in circuit 31S-CA33 (BK/OG) between soldered connection S161 and the blower switch using the Wiring Diagrams. CHECK the operation of the system. | | B9: CHECK THE BLOWER SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C110 from blower switch. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the blower switch, connector C110, pin 1, circuit 31S-CA30 (BK/WH), wiring harness side and ground. | | | 5 Measure the voltage between the blower switch, connector C110, pin 3, circuit 31S-CA31 (BK/YE), wiring harness side and ground. | | | 6 Measure the voltage between the blower switch, connector C110, pin 5, circuit 31S-CA32 (BK/BU), wiring harness side and ground. | | | Is battery voltage measured in all cases? Yes RENEW the blower switch. CHECK the operation of the system. No - Battery voltage not measured in any case: GO to B10. - Battery voltage not measured in one/two case(s): GO to B11. | | B10: CHECK THE VOLTAGE AT THE BLOWER RESISTOR ASSEMBLY | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C49 from the blower resistor assembly. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the blower resistor assembly, connector C49, pin 1, circuit 31S-CA18A (BK/RD), wiring harness side and ground. | | | Is battery voltage measured? Yes RENEW the blower resistor assembly. CHECK the operation of the system. No LOCATE and REPAIR the break in circuit 31S-CA18 (BK/RD) between the blower resistor assembly and soldered connection S161 using the Wiring Diagrams. CHECK the operation of the system. | | B11: CHECK THE CIRCUIT BETWEEN THE BLOWER RESISTOR ASSEMBLY AND THE BLOWER SWITCH FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C49 from the blower resistor assembly. | | | 3 Measure the resistance between the blower resistor assembly, connector C49, pin 4, circuit 31S-CA32 (BK/BU), wiring harness side and the blower switch, connector C110, pin 5, circuit 31S-CA32 (BK/BU), wiring harness side. | | | 4 Measure the resistance between the blower resistor assembly, connector C49, pin 2, circuit 31S-CA31 (BK/YE), wiring harness side and the blower switch, connector C110, pin 3, circuit 31S-CA31 (BK/YE), wiring harness side. | | | 5 Measure the resistance between the blower resistor assembly, connector C49, pin 3, circuit 31S-CA30 (BK/WH), wiring harness side and the blower switch, connector C110, pin 1, circuit 31S-CA30 (BK/WH), wiring harness side. | | | Is a resistance of less than 2 Ohm measured in all of the cases? Yes RENEW the blower resistor assembly. CHECK the operation of the system. No LOCATE and REPAIR the break in the relevant circuit between the blower resistor assembly and the blower switch using the Wiring Diagrams. CHECK the operation of the system. | | PINPOINT TEST C : BLOWER RUNNING CONTINUOUSLY | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE BLOWER SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C110 from blower switch. | | | 3 Ignition switch in position II. | | | 4 Check the operation of the blower. | | | Does the blower run continuously? Yes No RENEW the blower switch. CHECK the operation of the system. | | C2: CHECK THE CIRCUITS AT THE BLOWER RESISTOR ASSEMBLY FOR A SHORT CIRCUIT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C49 from the blower resistor assembly. | | | 3 Ignition switch in position II. | | | 4 Check the operation of the blower. | | | Does the blower run continuously? Yes CHECK all circuits that are connected to soldered connection S161 for a short to ground with the aid of the Wiring Diagrams and RECTIFY any short circuit(s) found. CHECK the operation of the system. No CHECK all circuits between the blower resistor assembly and the blower switch (vehicles with air conditioning system: additionally circuit 31S-CA25 (BK/GN) between the blower switch and the heater/air conditioning control assembly) for short circuit to ground using the Wiring Diagrams and REPAIR. CHECK the operation of the system. | | PINPOINT TEST D : AIR CONDITIONING INOPERATIVE (BLOWER AND HEATER OK) | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | D1: DETERMINE THE FAULT CONDITION | | | 1 Ignition switch in position III. | | | 2 Set the blower switch to position 1. | | | 3 Switch on the A/C. | | | Does the air conditioning clutch work? Yes Perform a Quick Check of the refrigerant circuit. No | | D2: CHECK THE CONTROL VOLTAGE AT THE AIR CONDITIONING CLUTCH RELAY | | | 1 Ignition switch in position 0. | | | 2 Disconnect A/C clutch relay C93. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the A/C clutch relay, socket C93, pin 1, circuit 94S-CA11 (VT/YE), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 94S-CA11 (VT/YE) between the A/C clutch relay and soldered connection S3 using the Wiring Diagrams. CHECK the operation of the system. | | D3: CHECK THE VOLTAGE AT THE AIR CONDITIONING CLUTCH RELAY | | | 1 Measure the voltage between the A/C clutch relay, socket C93, pin 5, circuit 14S-CA12 (VT/BU), wiring harness side and ground. | | | Is battery voltage measured? Yes No | | D4: CHECK THE VOLTAGE AT THE REFRIGERANT HIGH-PRESSURE SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C81 from the refrigerant high-pressure switch. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the refrigerant high-pressure switch, connector C81, pin 1, circuit 14-CA38 (VT), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 14-CA38 (VT) between the refrigerant high-pressure switch and soldered connection S13 using the Wiring Diagrams. CHECK the operation of the system. | | D5: CHECK REFRIGERANT HIGH-PRESSURE SWITCH | NOTE:Make certain that the refrigerant pressure is in the range between 3.0 and 10.5 bar (temperature dependent). If the pressure is higher, perform a refrigerant circuit Quick Check. If the pressure is lower, check the refrigerant circuit for leaks. | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance at the refrigerant high-pressure switch, connector C81, between pin 1 and pin 4, component side. | | | Is a resistance of less than 2 Ohm registered? Yes LOCATE and REPAIR the break in the circuit between the air conditioning clutch relay and the refrigerant high-pressure switch using the Wiring Diagrams. CHECK the operation of the system. No RENEW the refrigerant high-pressure switch. CHECK the operation of the system. | | D6: CHECK THE CIRCUIT OF THE A/C CLUTCH | | | 1 Ignition switch in position 0. | | | 2 Use a fused test cable (10 A) at the A/C clutch relay, socket C93, to jumper pin 3, circuit 14S-CA12 (VT/BU), wiring harness side and pin 5, circuit 14S-CA1 (VT/BU), wiring harness side. | | | 3 Ignition switch in position II. | | | Does the air conditioning clutch work? Yes No | | D7: CHECK THE VOLTAGE AT THE A/C CLUTCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C70 from air conditioning clutch. | | | 3 Use a fused test cable (10 A) at the A/C clutch relay, socket C93, to jumper pin 3, circuit 14S-CA1 (VT/BU), wiring harness side and pin 5, circuit 14S-CA12 (VT/BU), wiring harness side. | | | 4 Ignition switch in position II. | | | 5 Measure the voltage between the A/C clutch, connector C70, pin 2, circuit 14S-CA6 (VT/YE), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in the circuit between the air conditioning clutch relay and the air conditioning clutch using the Wiring Diagrams. CHECK the operation of the system. | | D8: CHECK THE GROUND CONNECTION OF THE A/C CLUTCH | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the A/C clutch, connector C70, pin 1, circuit 31-CA6 (BK), wiring harness side and ground. | | | Is a resistance of less than 2 Ohm registered? Yes RENEW the air conditioning clutch. CHECK the operation of the system. No LOCATE and REPAIR the break in the circuit between the A/C clutch and ground connection G2. CHECK the operation of the system. | | D9: CHECK THE VOLTAGE AT THE REFRIGERANT LOW PRESSURE SWITCH | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C80 from the refrigerant low-pressure switch. | | | 3 Ignition switch in position II. | | | 4 Set the blower switch to position 1. | | | 5 Switch on the A/C. | | | 6 Measure the voltage between the refrigerant low-pressure switch, connector C80, pin 4, circuit 14S-CA17 (VT/OG), wiring harness side and ground. | | | Is battery voltage measured? Yes No | | D10: CHECK THE REFRIGERANT LOW-PRESSURE SWITCH | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance at the refrigerant low-pressure switch, connector C80, between pin 1 and pin 4, component side. | | | Is a resistance of less than 2 Ohm registered? Yes No CHECK the quantity of refrigerant.
REFER to: Air Conditioning (A/C) System Recovery, Evacuation and Charging (412-00 Climate Control System - General Information, General Procedures).
If the system is filled with the correct refrigerant quantity, RENEW the refrigerant low-pressure switch. CHECK the operation of the system. | | D11: CHECK THE CONTROL VOLTAGE AT THE POWERTRAIN CONTROL MODULE (PCM) | | | 1 Disconnect connector C122 from PCM. | | | 2 Connect Connector C80 to the refrigerant low-pressure switch. | | | 3 Ignition switch in position II. | | | 4 Set the blower switch to position 1. | | | 5 Switch on the A/C. | | | 6 Measure the voltage between the PCM, connector C122, pin M40, circuit 14S-PC72 (VT/BU), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 14S-PC72 (VT/BU) between the refrigerant low-pressure switch and the PCM using the Wiring Diagrams. CHECK the operation of the system. | | D12: CHECK FOR OPEN CIRCUIT BETWEEN AIR CONDITIONING CLUTCH RELAY AND PCM | | | 1 Measure the resistance between the air conditioning clutch relay, socket C93, pin 2, circuit 91S-CA11 (BK/YE), wiring harness side and the PCM, connector C122, pin M26, circuit 91S-CA11 (BK/YE), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 91S-CA11 (BK/YE) between the air conditioning clutch relay and the PCM using the Wiring Diagrams. CHECK the operation of the system. | | D13: CHECK THE CIRCUIT BETWEEN THE AIR CONDITIONING CLUTCH RELAY AND THE PCM FOR SHORT TO VOLTAGE | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the A/C clutch relay, socket C93, pin 2, circuit 91S-CA11 (BK/YE), wiring harness side and ground. | | | Is a voltage measured? Yes No LOCATE and REPAIR the short to voltage in circuit 91S-CA11 (BK/YE) between the air conditioning clutch relay and the PCM using the Wiring Diagrams. CHECK the operation of the system. | | D14: CHECK THE A/C CLUTCH RELAY | NOTE:If the powertrain control module (PCM) is changed, the new one must be programmed. For this purpose, the vehicle-specific data is read out of the module to be replaced using WDS and is transferred to the new module. | | | 1 Check the A/C clutch relay according to the component test at the end of this section. | | | Is the A/C clutch relay OK? Yes CHECK the PCM and RENEW if necessary. CHECK the operation of the system. No RENEW the air conditioning clutch relay. CHECK and if necessary RENEW the air conditioning clutch diode. CHECK the operation of the system. | | D15: CHECK THE CIRCUIT BETWEEN THE A/C RELAY AND THE REFRIGERANT LOW-PRESSURE SWITCH FOR OPEN CIRCUIT. | | | 1 Ignition switch in position 0. | | | 2 Disconnect A/C relay C154 (CJB). | | | 3 Measure the resistance between the A/C relay, socket C154, pin 3, circuit 14S-CA17 (VT/OG), wiring harness side and the refrigerant low-pressure switch, connector C80, pin 4, circuit 14S-CA17 (VT/OG), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 14S-CA17 (VT/OG) between the A/C relay and the refrigerant low-pressure switch using the Wiring Diagrams. CHECK the operation of the system. | | D16: CHECK THE CONTROL VOLTAGE AT THE A/C RELAY | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the A/C relay, socket C154, pin 2, circuit 94S-CA66 (VT/OG), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 94S-CA66 (VT/OG) between the A/C relay and soldered connection S3 using the Wiring Diagrams. CHECK the operation of the system. | | D17: CHECK THE VOLTAGE AT A/C RELAY | | | 1 Measure the voltage between the A/C relay, socket C154, pin 5, circuit 14S-CA67 (VT/BK), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 14S-CA67 (VT/BK) between the A/C relay and the refrigerant high-pressure switch using the Wiring Diagrams. CHECK the operation of the system. | | D18: TEST THE CIRCUIT BETWEEN THE A/C RELAY AND THE A/C CONTROL ASSEMBLY FOR OPEN CIRCUIT | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C109 from A/C control assembly. | | | 3 Measure the resistance between the A/C relay, socket C154, pin 1, circuit 31S-CA66 (BK/RD), wiring harness side and the air conditioning control assembly, connector C109, pin 11, circuit 31S-CA66 (BK/RD), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 31S-CA66 (BK/RD) between the A/C relay and the air conditioning control assembly using the Wiring Diagrams. CHECK the operation of the system. | | D19: CHECK THE CIRCUIT BETWEEN THE A/C RELAY AND THE A/C CONTROL ASSEMBLY FOR SHORT TO VOLTAGE | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the A/C relay, socket C154, pin 1, circuit 31S-CA66 (BK/RD), wiring harness side and ground. | | | Is a voltage measured? Yes LOCATE and REPAIR the short to voltage supply in circuit 31S-CA66 (BK/RD) between the A/C relay and the air conditioning control assembly using the Wiring Diagrams. CHECK the operation of the system. No | | D20: CHECK THE VOLTAGE AT THE AIR CONDITIONING CONTROL ASSEMBLY | | | 1 Set the blower switch to position 0. | | | 2 Measure the voltage between the air conditioning control assembly, connector C109, pin 5, circuit 31S-CA25 (BK/GN), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 31S-CA25 (BK/GN) between the air conditioning control assembly and the blower switch using the Wiring Diagrams. CHECK the operation of the system. | | D21: CHECK THE A/C RELAY | | | 1 Ignition switch in position 0. | | | 2 Check the A/C relay according to the component test at the end of this section. | | | Is the A/C relay OK? Yes CHECK and if necessary RENEW the air conditioning control assembly. CHECK the operation of the system. No RENEW the A/C relay. CHECK the operation of the system. | | PINPOINT TEST E : MALFUNCTION OF THE AIR RECIRCULATION FLAP - VEHICLES WITH A/C (HEATER AND A/C OK) | NOTE:Air recirculation mode is not available if the air distribution control is set to "Defrost/demist windscreen". | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | E1: CHECK THE VOLTAGE AT THE AIR FLAP ACTUATOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C47 from the air flap actuator. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the air flap actuator, connector C47, pin 2, circuit 14-CA76 (VT), wiring harness side and ground. | | | Is battery voltage measured? Yes No LOCATE and REPAIR the break in circuit 14-CA76 (VT) between the air flap actuator and soldered connection S160 using the Wiring Diagrams. CHECK the operation of the system. | | E2: CHECK THE GROUND CONNECTION OF THE AIR FLAP ACTUATOR | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the air flap actuator, connector C47, pin 3, circuit 31-CA76 (BK), wiring harness side and ground. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 31-CA76 (BK) between the air flap actuator and soldered connection S14 using the Wiring Diagrams. CHECK the operation of the system. | | E3: CHECK THE CONTROL VOLTAGE AT THE AIR FLAP ACTUATOR | | | 1 Ignition switch in position II. | | | 2 Switch off the air recirculation system. | | | 3 Measure the voltage between the air flap actuator, connector C47, pin 1, circuit 31S-CA76 (BK/OG), wiring harness side and ground. | | | Is battery voltage measured? Yes No | | E4: CHECK FOR OPEN CIRCUIT BETWEEN THE AIR CONDITIONING CONTROL ASSEMBLY AND THE AIR FLAP ACTUATOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C109 from A/C control assembly. | | | 3 Measure the resistance between the air conditioning control assembly, connector C109, pin 4, circuit 31S-CA76 (BK/OG), wiring harness side and the air flap actuator, connector C47, pin 1, circuit 31S-CA76 (BK/OG), wiring harness side. | | | Is a resistance of less than 2 Ohm registered? Yes No LOCATE and REPAIR the break in circuit 31S-CA46 (BK/OG) between the air conditioning control assembly and the air flap actuator using the Wiring Diagrams. CHECK the operation of the system. | | E5: CHECK CIRCUIT BETWEEN AIR CONDITIONING CONTROL ASSEMBLY AND AIR FLAP ACTUATOR FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the air flap actuator, connector C47, pin 1, circuit 31S-CA76 (BK/OG), wiring harness side and ground. | | | Is a resistance of less than 10,000 Ohm registered? Yes LOCATE and REPAIR the short to ground in circuit 31S-CA76 (BK/OG) between the air conditioning control assembly and the air flap actuator using the Wiring Diagrams. CHECK the operation of the system. No CHECK and if necessary RENEW the air conditioning control assembly. CHECK the operation of the system. | | E6: CHECK THE CONTROL VOLTAGE AT THE AIR FLAP ACTUATOR | | | 1 Switch on the air recirculation system. | | | 2 Measure the voltage between the air flap actuator, connector C47, pin 1, circuit 31S-CA76 (BK/OG), wiring harness side and ground. | | | Is a voltage measured? Yes No CHECK the air recirculation flap for ease of movement and correct operation. If the air recirculation flap is OK, RENEW the air flap actuator. CHECK the operation of the system. | | E7: CHECK CIRCUIT BETWEEN AIR CONDITIONING CONTROL ASSEMBLY AND AIR FLAP ACTUATOR FOR SHORT TO VOLTAGE SUPPLY | | | 1 Ignition switch in position 0. | | | 2 Disconnect Connector C109 from A/C control assembly. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the air flap actuator, connector C47, pin 1, circuit 31S-CA76 (BK/OG), wiring harness side and ground. | | | Is a voltage measured? Yes LOCATE and REPAIR the short to voltage supply in circuit 31S-CA76 (BK/OG) between the air conditioning control assembly and the air flap actuator using the Wiring Diagrams. CHECK the operation of the system. No CHECK and if necessary RENEW the air conditioning control assembly. CHECK the operation of the system. | Component Tests A/C clutch relay - Check the normally open contact in the unswitched state:
- a) Measure the resistance at the air conditioning clutch relay, between pin 3 and pin 5, component side.
- Check the normally open contact in the switched state:
- a) Use a fused test cable (1 A) to connect pin 1 of the air conditioning clutch relay, component side, to the battery positive terminal.
- b) Use a test cable to connect pin 2 of the air conditioning clutch relay, component side, to the battery negative terminal.
- c) Measure the resistance at the air conditioning clutch relay, between pin 3 and pin 5, component side.
- d) Is a resistance of less than 2 Ohm measured?
1. If yes, then the air conditioning clutch relay is OK. 2. If no, RENEW the air conditioning clutch relay. A/C relay - Check the normally open contact in the unswitched state:
- a) Measure the resistance at the air conditioning relay, between pin 3 and pin 5, component side.
- Check the normally open contact in the switched state:
- a) Use a fused test cable (1 A) to connect pin 1 of the air conditioning relay, component side, to the battery positive terminal.
- b) Use a test cable to connect pin 2 of the air conditioning relay, component side, to the battery negative terminal.
- c) Measure the resistance at the air conditioning relay, between pin 3 and pin 5, component side.
- d) Is a resistance of less than 2 Ohm measured?
1. If yes, the air conditioning relay is OK. 2. If no, RENEW the air conditioning relay. |
