| Diagnosis and Testing Refer to Wiring Diagrams Section 412-00, for schematic and connector information. Special Tool(s) | | Terminal probe kit 418-S035 | General Equipment Digital multimeter World wide diagnostic system (WDS) Inspection and Verification - VERIFY the customer concern.
- Visually INSPECT for obvious signs of mechanical or electrical damage.
Visual Inspection Chart | Mechanical | Electrical | - Coolant level
- Coolant hoses
| - Fuses
- Wiring harness
- Connectors
| - If an obvious cause for an observed or reported concern is found, CORRECT the cause (if possible) before proceeding to the next step. TEST the system for normal operation.
- If the cause is not visually evident, CHECK the powertrain control module (PCM) by using the WDS. If an error code is displayed, CORRECT the cause by using the WDS. TEST the system for normal operation.
- If there is no error code displayed, VERIFY the symptom and REFER to the Symptom Chart.
- After the test or elimination of a concern CHECK all modules that are installed on the vehicle by using the WDS. ERASE all error codes. CARRY out a road test of the vehicle. CHECK all modules again.
Symptom Chart Symptom Chart | Symptom | Possible Sources | Action | | The heater blower motor is inoperative | * Fuse(s) * Circuit(s) * Heater blower motor * Heater blower switch * Heater blower series resistor | * | | Insufficient, erratic or no heat | * Fuse(s) * Circuit(s) * Heater control module * Heater control solenoid valve * Coolant hoses * Air in coolant system | * | | The recirculation air flap is inoperative (heater blower and heating are OK) | * Circuit(s) * Recirculation air flap * Recirculation air actuator * Heater control module | * | | Condensation water from the air conditioning system drips/flows into the footwell | * Air conditioning outlet pipe is not connected to the heater core and evaporator core housing * Air conditioning outlet pipe is incorrectly routed through the body panel * Air conditioning outlet pipe is bent or blocked | * CHECK the outlet pipe and the rubber grommet and REPAIR if not OK | Pinpoint Tests | PINPOINT TEST A : THE HEATER BLOWER MOTOR IS INOPERATIVE | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | A1: DETERMINE THE FAULT CONDITION | | | 1 Ignition switch in position II. | | | 2 Turn the heater blower switch from OFF to HIGH SPEED position and back. | | | Is the heater blower motor in all positions inoperative? Yes No - Only HIGH SPEED is inoperative: GO to A8. - SLOW, LOW SPEED and/or MEDIUM SPEED is/are inoperative: GO to A9. | | A2: CHECK FUSE F16 | | | 1 Ignition switch in position 0. | | | 2 CHECK fuse F16 (CJB). | | | Is the fuse OK? Yes No INSTALL a new fuse F16 (30 A). TEST the system for normal operation. If the fuse blows again, LOCATE and REPAIR the short circuit by using the wiring diagrams. | | A3: CHECK THE VOLTAGE AT FUSE F16 | | | 1 Connect fuse F16 (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F16 (30 A) and ground. | | | Is battery voltage indicated? Yes No REPAIR the power supply of fuse F16 by using the wiring diagrams. TEST the system for normal operation. | | A4: CHECK THE VOLTAGE AT THE HEATER BLOWER MOTOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C53 of heater blower motor. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater blower motor, connector C53, pin 1, circuit 14-CA18 (VT/OG), harness side and ground. | | | Is battery voltage indicated? Yes No REPAIR the open circuit between fuse F16 and the heater blower motor by using the wiring diagrams. TEST the system for normal operation. | | A5: CHECK THE GROUND CONNECTION OF THE HEATER BLOWER MOTOR | | | 1 Ignition switch in position 0. | | | 2 Turn the heater blower switch to HIGH SPEED position. | | | 3 Measure the resistance between the heater blower motor, connector C53, pin 2, circuit 31S-CA18 (BK/RD), harness side and ground. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower motor. TEST the system for normal operation. No | | A6: CHECK THE CIRCUIT BETWEEN THE HEATER BLOWER MOTOR AND THE HEATER BLOWER SWITCH FOR OPEN | | | 1 Disconnect connector C72 of heater blower switch. | | | 2 Measure the resistance between the heater blower motor, connector C53, pin 2, circuit 31S-CA18 (BK/RD), harness side and the heater blower switch, connector C72, pin 4, circuit 31S-CA33 (BK/OG), harness side. | | | Is the resistance less than 2 ohms? Yes No REPAIR the open circuit 31S-CA18 (BK/RD) between the heater blower motor and splice S33 by using the wiring diagrams. TEST the system for normal operation. | | A7: CHECK THE GROUND CONNECTION OF THE HEATER BLOWER SWITCH | | | 1 Measure the resistance between the heater blower switch, connector C72, pin 6, circuit 31-CA25 (BK), harness side and ground. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower switch. TEST the system for normal operation. No REPAIR the open circuit between the heater blower switch and ground G6 by using the wiring diagrams. TEST the system for normal operation. | | A8: CHECK THE CIRCUIT BETWEEN THE HEATER BLOWER MOTOR AND THE HEATER BLOWER SWITCH FOR OPEN | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C72 of heater blower switch. | | | 3 Disconnect connector C53 of heater blower motor. | | | 4 Measure the resistance between the heater blower motor, connector C53, pin 2, circuit 31S-CA18 (BK/RD), harness side and the heater blower switch, connector C72, pin 4, circuit 31S-CA33 (BK/OG), harness side. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower switch. TEST the system for normal operation. No REPAIR the open circuit 31S-CA33 (BK/OG) between the heater blower switch and splice S33 by using the wiring diagrams. TEST the system for normal operation. | | A9: CHECK THE VOLTAGE AT THE HEATER BLOWER SWITCH - MEDIUM SPEED | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C72 of heater blower switch. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater blower switch, connector C72, pin 1, circuit 31S-CA32 (BK/BU), harness side and ground. | | | Is battery voltage indicated? Yes No | | A10: CHECK THE VOLTAGE AT THE HEATER BLOWER SERIES RESISTOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C90 of heater blower series resistor. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater blower series resistor, connector C90, pin 1, circuit 31S-CA18A (BK/RD), harness side and ground. | | | Is battery voltage indicated? Yes No REPAIR the open circuit 31S-CA18A (BK/RD) between splice S33 and the heater blower series resistor by using the wiring diagrams. TEST the system for normal operation. | | A11: CHECK THE CIRCUIT BETWEEN THE HEATER BLOWER SERIES RESISTOR AND THE HEATER BLOWER SWITCH FOR OPEN - MEDIUM SPEED | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the heater blower series resistor, connector C90, pin 4, circuit 31S-CA32 (BK/BU), harness side and the heater blower switch, connector C72, pin 1, circuit 31S-CA32 (BK/BU), harness side. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower series resistor. TEST the system for normal operation. No REPAIR the open circuit 31S-CA32 (BK/BU) between the heater blower series resistor and the heater blower switch by using the wiring diagrams. TEST the system for normal operation. | | A12: CHECK THE VOLTAGE AT THE HEATER BLOWER SWITCH - LOW SPEED | | | 1 Measure the voltage between the heater blower switch, connector C72, pin 2, circuit 31S-CA31 (BK/YE), harness side and ground. | | | Is battery voltage indicated? Yes No | | A13: CHECK THE CIRCUIT BETWEEN THE HEATER BLOWER SERIES RESISTOR AND THE HEATER BLOWER SWITCH FOR OPEN - LOW SPEED | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C90 of heater blower series resistor. | | | 3 Measure the resistance between the heater blower series resistor, connector C90, pin 2, circuit 31S-CA31 (BK/YE), harness side and the heater blower switch, connector C72, pin 2, circuit 31S-CA31 (BK/YE), harness side. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower series resistor. TEST the system for normal operation. No REPAIR the open circuit 31S-CA31 (BK/YE) between the heater blower series resistor and the heater blower switch by using the wiring diagrams. TEST the system for normal operation. | | A14: CHECK THE VOLTAGE AT THE HEATER BLOWER SWITCH - SLOW | | | 1 Measure the voltage between the heater blower switch, connector C72, pin 3, circuit 31S-CA30 (BK/WH), harness side and ground. | | | Is battery voltage indicated? Yes INSTALL a new heater blower switch. TEST the system for normal operation. No | | A15: CHECK THE CIRCUIT BETWEEN THE HEATER BLOWER SERIES RESISTOR AND THE HEATER BLOWER SWITCH FOR OPEN - SLOW | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C90 of heater blower series resistor. | | | 3 Measure the resistance between the heater blower series resistor, connector C90, pin 3, circuit 31S-CA30 (BK/WH), harness side and the heater blower switch, connector C72, pin 3, circuit 31S-CA30 (BK/WH), harness side. | | | Is the resistance less than 2 ohms? Yes INSTALL a new heater blower series resistor. TEST the system for normal operation. No REPAIR the open circuit 31S-CA30 (BK/WH) between the heater blower series resistor and the heater blower switch by using the wiring diagrams. TEST the system for normal operation. | | PINPOINT TEST B : INSUFFICIENT, ERRATIC OR NO HEAT | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | B1: CHECK FUSE F13 | | | 1 Ignition switch in position 0. | | | 2 CHECK fuse F13 (CJB). | | | Is the fuse OK? Yes No INSTALL a new fuse F13 (15 A). TEST the system for normal operation. If the fuse blows again, LOCATE and REPAIR the short circuit by using the wiring diagrams. | | B2: CHECK THE VOLTAGE AT FUSE F13 | | | 1 Connect fuse F13 (CJB). | | | 2 Ignition switch in position II. | | | 3 Measure the voltage between fuse F13 (15 A) and ground. | | | Is battery voltage indicated? Yes No REPAIR the power supply of fuse F13 by using the wiring diagrams. TEST the system for normal operation. | | B3: CHECK FUSE F2 | | | 1 Ignition switch in position 0. | | | 2 CHECK fuse F2 (CJB). | | | Is the fuse OK? Yes No INSTALL a new fuse F2 (10 A). TEST the system for normal operation. If the fuse blows again, LOCATE and REPAIR the short circuit by using the wiring diagrams. | | B4: CHECK THE VOLTAGE AT FUSE F2 | | | 1 Connect fuse F2 (CJB). | | | 2 Measure the voltage between fuse F2 (10 A) and ground. | | | Is battery voltage indicated? Yes No REPAIR the power supply of fuse F2 by using the wiring diagrams. TEST the system for normal operation. | | B5: DETERMINE THE FAULT CONDITION OF THE HEATING SYSTEM | NOTE:If the temperature adjustment is changed, the heater control solenoid valve is reacting with a short delay in time. | | | 1 Start and run the engine until the operation temperature is normal. | | | 2 Set the temperature selector switch to HOT position. | | | 3 Check the temperature of the air flow. | | | Is the air flow permanently cold? Yes No | | B6: CHECK THE HEATER CONTROL SOLENOID VALVE | WARNING:Do not carry out any repairs to the heater control solenoid valve before the heater control solenoid valve surface temperature is at ambient temperature. Failure to follow these instructions may result in personal injury. | | | 1 Turn the temperature selector switch to the medium position. | | | 2 Check the heater control solenoid valve for pulsating. | | | Is the heater control solenoid valve pulsating? Yes CHECK the heater control solenoid valve for blockages. If necessary, INSTALL a new one. TEST the system for normal operation. No | | B7: CHECK THE VOLTAGE AT THE HEATER CONTROL SOLENOID VALVE | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C49 of heater control solenoid valve. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the heater control solenoid valve, connector C49, pin 1, circuit 14-CA82 (VT/BK), harness side and ground. | | | Is battery voltage indicated? Yes No LOCATE and REPAIR the open in circuits between fuse F13 and the heater control solenoid valve by using the wiring diagrams. TEST the system for normal operation. | | B8: CHECK THE CIRCUITS OF THE HEATER CONTROL SOLENOID VALVE | | | 1 Ignition switch in position III. | | | 2 Turn the temperature selector switch to the medium position. | | | 3 Measure the voltage at the heater control solenoid valve, connector C49, between pin 1, circuit 14-CA82 (VT/BK), harness side and pin 2, circuit 31S-CA82 (BK/GN), harness side. | | | Is an alternating voltage between 0 volt and battery voltage indicated? Yes INSTALL a new heater control solenoid valve. TEST the system for normal operation. No | | B9: CHECK THE VOLTAGE AT THE HEATER CONTROL MODULE - PIN 2 | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C28 of heater control module. | | | 3 Measure the voltage between the heater control module, connector C28, pin 2, circuit 29-CA83 (OG/GN), harness side and ground. | | | Is battery voltage indicated? Yes No REPAIR the open circuit between fuse F2 and the heater control module by using the wiring diagrams. TEST the system for normal operation. | | B10: CHECK THE VOLTAGE AT THE HEATER CONTROL MODULE - PIN 12 | | | 1 Ignition switch in position II. | | | 2 Measure the voltage between the heater control module, connector C28, pin 12, circuit 14-CA83 (VT/OG), harness side and ground. | | | Is battery voltage indicated? Yes No REPAIR the open circuit 14-CA83 (VT/OG) between the heater control module and splice S12 by using the wiring diagrams. TEST the system for normal operation. | | B11: CHECK THE CIRCUIT BETWEEN THE HEATER CONTROL SOLENOID VALVE AND THE HEATER CONTROL MODULE FOR OPEN | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the heater control solenoid valve, connector C49, pin 2, circuit 31S-CA82 (BK/GN), harness side and the heater control module, connector C28, pin 5, circuit 31S-CA82 (BK/GN), harness side. | | | Is the resistance less than 2 ohms? Yes No REPAIR the open circuit 31S-CA82 (BK/GN) between the heater control solenoid valve and the heater control module by using the wiring diagrams. TEST the system for normal operation. | | B12: CHECK THE GROUND CONNECTION OF THE HEATER CONTROL MODULE | | | 1 Measure the resistance between the heater control module, connector C28, pin 6, circuit 91-CA83 (BK/RD), harness side and ground. | | | Is the resistance less than 2 ohms? Yes CHECK the heater control module. If necessary, INSTALL a new one. TEST the system for normal operation. No REPAIR the open circuit 91-CA83 (BK/RD) between the heater control module and ground G5 by using the wiring diagrams. TEST the system for normal operation. | | B13: CHECK THE HEATER CONTROL SOLENOID VALVE | WARNING:Do not carry out any repairs to the heater control solenoid valve before the heater control solenoid valve surface temperature is at ambient temperature. Failure to follow these instructions may result in personal injury. | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C49 of heater control solenoid valve. | | | 3 Ignition switch in position III. | | | 4 Check the temperature of the air flow. | | | Is the air flow permanent cold? Yes CHECK whether the coolant hoses are routed correctly. If necessary BLEED the cooling system. If the cooling system is OK, CHECK the heater control solenoid valve for blockages. If necessary, INSTALL a new one. TEST the system for normal operation. No | | B14: CHECK THE CIRCUIT BETWEEN THE HEATER CONTROL MODULE AND THE HEATER CONTROL SOLENOID VALVE FOR SHORT TO GROUND | | | 1 Ignition switch in position 0. | | | 2 Connect connector C49 of heater control solenoid valve. | | | 3 Disconnect connector C28 of heater control module. | | | 4 Ignition switch in position III. | | | 5 Check the temperature of the air flow. | | | Is the air flow permanently cold? Yes LOCATE and REPAIR the short to ground in circuit 31S-CA82 (BK/GN) between the heater control solenoid valve and the heater control module by using the wiring diagrams. TEST the system for normal operation. No | | B15: CHECK THE TACHOMETERSIGNAL AT THE HEATER CONTROL MODULE | NOTE:If the heater control module does not receive a tachometer signal, the heater will stay cold permanently. | | | 1 Let the engine idle. | | | NOTE:Carry out the measurement by using the WDS. For the measurement select "AC" in multimeter mode. 2 Measure the voltage between the heater control module, connector C28, pin 1, circuit 8-GB10A (WH/BK)(Vehicles with petrol engine and without tachometer: circuit 8-GB10 (WH/BK)), harness side and ground. | | | Is a voltage approx. 9 volts indicated? Yes CHECK the heater control module. If necessary, INSTALL a new one. TEST the system for normal operation. No - All except vehicles with petrol engine and without tachometer: CHECK and if necessary REPAIR the open circuit 8-GB10A (WH/BK) between splice S32 and the heater control module by using the wiring diagrams. TEST the system for normal operation. If the concern is not rectified REFER to Section 413-01 Instrument Cluster. - Vehicles with petrol engine and without tachometer: CHECK and if necessary REPAIR the open circuit 8-GB10 (WH/BK) between Powertrain control module (PCM) and the heater control module by using the wiring diagrams. TEST the system for normal operation. If the concern is not rectified REFER to Section 303-14 Electronic Engine Controls. | | PINPOINT TEST C : THE RECIRCULATION AIR FLAP IS INOPERATIVE (HEATER BLOWER AND HEATING ARE OK) | | TEST CONDITIONS | DETAILS/RESULTS/ACTIONS | | C1: CHECK THE VOLTAGE AT THE RECIRCULATION AIR ACTUATOR | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C54 of recirculation air actuator. | | | 3 Ignition switch in position II. | | | 4 Measure the voltage between the recirculation air actuator, connector C54, pin 2, circuit 14-CA76 (VT), harness side and ground. | | | Is battery voltage indicated? Yes No REPAIR the open circuit 14-CA76 (VT) between the recirculation air actuator and splice S13 by using the wiring diagrams. TEST the system for normal operation. | | C2: CHECK THE GROUND CONNECTION OF THE RECIRCULATION AIR ACTUATOR | | | 1 Ignition switch in position 0. | | | 2 Measure the resistance between the recirculation air actuator, connector C54, pin 3, circuit 31-CA76 (BK), harness side and ground. | | | Is the resistance less than 2 ohms? Yes No REPAIR the open circuit 31-CA76 (BK) between the recirculation air actuator and splice S5 by using the wiring diagrams. TEST the system for normal operation. | | C3: CHECK THE CONTROL VOLTAGE AT THE RECIRCULATION AIR ACTUATOR - OFF POSITION | | | 1 Ignition switch in position II. | | | 2 Switch off the air recirculation. | | | 3 Measure the voltage between the recirculation air actuator, connector C54, pin 1, circuit 31S-CA76 (BK/OG), harness side and ground. | | | Is battery voltage indicated? Yes No | | C4: CHECK THE CONTROL VOLTAGE AT THE RECIRCULATION AIR ACTUATOR - ON POSITION | | | 1 Switch on the air recirculation. | | | 2 Measure the voltage between the recirculation air actuator, connector C54, pin 1, circuit 31S-CA76 (BK/OG), harness side and ground. | | | Is any voltage indicated? Yes No CHECK the mountings/attachments and the operation of the recirculation air flap. If the recirculation air flap is OK, INSTALL a new recirculation air actuator. TEST the system for normal operation. | | C5: CHECK THE CIRCUIT BETWEEN THE HEATER CONTROL MODULE AND THE RECIRCULATION AIR ACTUATOR FOR SHORT TO POWER | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C28 of heater control module. | | | 3 Measure the voltage between the recirculation air actuator, connector C54, pin 1, circuit 31S-CA76 (BK/OG), harness side and ground. | | | Is any voltage indicated? Yes LOCATE and REPAIR the short to power in circuit 31S-CA76 (BK/OG) between the heater control module and the recirculation air actuator by using the wiring diagrams. TEST the system for normal operation. No CHECK the heater control module. If necessary, INSTALL a new one. TEST the system for normal operation. | | C6: CHECK THE CIRCUIT BETWEEN THE HEATER CONTROL MODULE AND THE RECIRCULATION AIR ACTUATOR FOR OPEN | | | 1 Ignition switch in position 0. | | | 2 Disconnect connector C28 of heater control module. | | | 3 Measure the resistance between the recirculation air actuator, connector C54, pin 1, circuit 31S-CA76 (BK/OG), harness side and the heater control module, connector C28, pin 9, circuit 31S-CA76 (BK/OG), harness side. | | | Is the resistance less than 2 ohms? Yes No REPAIR the open circuit 31S-CA76 (BK/OG) between the heater control module and the recirculation air actuator by using the wiring diagrams. TEST the system for normal operation. | | C7: CHECK THE CONTROL CIRCUIT BETWEEN THE HEATER CONTROL MODULE AND THE RECIRCULATION AIR ACTUATOR FOR SHORT TO GROUND | | | 1 Measure the resistance between the recirculation air actuator, connector C54, pin 1, circuit 31S-CA76 (BK/OG), harness side and ground. | | | Is the resistance less than 10,000 ohms? Yes LOCATE and REPAIR the short to ground in circuit 31S-CA76 (BK/OG) between the heater control module and the recirculation air actuator by using the wiring diagrams. TEST the system for normal operation. No CHECK the heater control module. If necessary, INSTALL a new one. TEST the system for normal operation. | |
