Ford Workshop Service and Repair Manuals > Transit 2000.5 (01.2000-05.2006) > Mechanical Repairs | 4 Electrical | 412 Climate Control System | 412-05 Refrigeration | Description and Operation | Diagnosis and Testing

General Procedures > < Refrigeration

Refrigeration - Refrigeration

Transit 2000.5 (01/2000-05/2006)

Diagnosis and Testing

Special Tool(s)

Terminal Probe Kit

418-S035

General Equipment

Worldwide Diagnostic System (WDS)

Inspection and Checking

WARNING:Repair work to the 230 V system may only be carried out by trained personnel. Failure to observe this instruction can lead to injury.

VERIFY customer concern.

Visually CHECK for any obvious mechanical or electrical damage.

Visual Inspection

Mechanical	Electrical
Drive belt Refrigerant lines Condenser Refrigerant compressor	Fuses Wiring harness Connectors

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, use WDS to PERFORM a fault diagnosis of the electronic engine management (PCM) and RESOLVE the fault(s) displayed according to the fault description. CHECK the operation of the system.

If the concern persists after the visual inspection, PROCEED as indicated on the symptom chart.

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.

Symptom Chart

WARNING:Repair work to the 230 V system may only be carried out by trained personnel. Failure to observe this instruction can lead to injury.

Symptom Chart

Symptom	Possible Sources	Action
Mobile refrigeration inoperative	* Fuse(s) * Circuit(s) * Refrigerant quantity / circuit * Refrigeration system switch * Refrigeration system control module * Refrigeration system control assembly * Compressor temperature switch * Refrigeration system evaporator core * Refrigeration system compressor clutch * Refrigeration system compressor clutch diode * A/C indicator diode * Refrigeration system low pressure switch * Refrigeration system high pressure switch * Refrigeration system wide open throttle (WOT) relay * Powertrain control module (PCM)	* GO to Pinpoint Test A.
Stationary refrigeration inoperative (mobile refrigeration OK)	* Fuse(s) * Circuit(s) * Refrigeration system control module * Stationary refrigeration power supply switch box * Stationary refrigeration power supply transformer * Stationary refrigeration socket * Stationary refrigeration motor * Stationary refrigeration compressor clutch	* GO to Pinpoint Test B.
Radiator fan inoperative when stationary refrigeration is operating (operation OK with mobile refrigeration)	* Circuit(s) * Refrigeration system control module * Stationary refrigeration relay	* - Vehicles built up to 11/2002: GO to Pinpoint Test C. * - Vehicles built from 11/2002: GO to Pinpoint Test D.
Evaporator core fans inoperative	* Circuit(s) * Refrigeration system control assembly * Evaporator core temperature sensor * Refrigeration system control module * Refrigeration system evaporator core	* GO to Pinpoint Test E.
Inadequate cooling power from the refrigeration system (operation of refrigeration compressor clutch OK)x	* Cooling fan * Condenser * Refrigerant quantity * Refrigerant circuit	* PERFORM a fault diagnosis of the electronic engine management (PCM) with WDS and RESOLVE the fault(s) displayed according to the fault description. CHECK the operation of the system. * CHECK the refrigerant quantity/circuit according to the component check at the end of this section and REPAIR if necessary.

System Checks

PINPOINT TEST C : RADIATOR FAN INOPERATIVE WHEN STATIONARY REFRIGERATION IS OPERATING - VEHICLES BUILT UP TO 11/2002 (OPERATION OK WITH MOBILE REFRIGERATION)

TEST CONDITIONS DETAILS/RESULTS/ACTIONS

C1: CHECK FOR OPEN CIRCUIT BETWEEN THE REFRIGERATION SYSTEM CONTROL MODULE AND THE RADIATOR FAN MOTOR.

1

Ignition switch in position 0.

2

Switch off the stationary refrigeration at the stationary refrigeration main switch.

3

Disconnect connector C7041 from the refrigeration system control module.

4

Disconnect connector C4062 from the radiator fan motor.

5

Measure the resistance between the radiator fan motor, connector C4062, pin 3, circuit 30S-PA9 (RD/WH), wiring harness side and the refrigeration system control module, connector C7041, pin 5, (RD/WH), wiring harness side.

6

Measure the resistance between the radiator fan motor, connector C4062, pin 3, circuit 30S-PA9 (RD/WH), wiring harness side and the refrigeration system control module, connector C7041, pin 6, (RD/WH), wiring harness side.

Is a resistance of less than 2 Ohms measured in both cases?

Yes

RENEW the refrigeration system control module. CHECK the operation of the system.

No

LOCATE and REPAIR the open circuit between the refrigeration system control module and soldered connection S1120 using the Wiring Diagrams. CHECK the operation of the system.

Component Tests

Loading space temperature sensor

Measure the resistance at the loading space temperature sensor between pin 1 and pin 3, component side.

Compare the resistance value obtained with the following table:

The applicable tolerance range which describes the "normal" range for a measured value lies between the upper and lower curves.

Co-ordinate axis	Description
1	Loading space temperature in °C
2	Loading space temperature sensor resistance in Ohm

Does the resistance value obtained correspond to the specification?
1. Yes: The loading space temperature sensor is OK.
1. No: RENEW the loading space temperature sensor, if necessary RENEW the refrigeration system evaporator core.

Evaporator core temperature sensor

Measure the resistance at the evaporator core temperature sensor between pin 1 and pin 2, component side.

Compare the resistance value obtained with the following table:

The applicable tolerance range which describes the "normal" range for a measured value lies between the upper and lower curves.

Co-ordinate axis	Description
1	Evaporator core temperature in °C
2	Evaporator core temperature sensor resistance in Ohm

Does the resistance value obtained correspond to the specification?
1. Yes: The evaporator core temperature sensor is OK.
1. No: RENEW the evaporator core temperature sensor, if necessary RENEW the refrigeration system evaporator core.

Refrigeration system wide open throttle (WOT) relay

Check the normally open contact in the unswitched state:
1. Measure the resistance at the relay between pin 3, component side, and pin 5, component side.
1. Is a resistance of more than 10,000 Ohm measured?
1. If yes, go to 2.
1. If no, RENEW the relay.

Check the normally open contact in the switched state:
1. Use a fused test cable (1 A) to connect pin 1 of the relay, component side, to the battery positive terminal.
1. Use a test cable to connect pin 2 of the relay, component side, to the battery negative terminal.
1. Measure the resistance at the relay, between pin 3, component side, and pin 5, component side.
1. Is a resistance of less than 2 Ohm registered?
1. If yes, then the relay is OK.
1. If no, RENEW the relay.

Check refrigeration system capacity

Test preparations

The following values must be determined:

Loading space temperature
Refrigeration period

In order to achieve a precise measurement, the loading space temperature must be at least + 18° C when beginning the measurement. It is important to ensure an even temperature throughout the loading space. This can be achieved through ventilation by leaving the loading space doors open for a suitable period of time (at least 1 hour). The following steps must then be performed:

NOTE:The thermometer must not be directly exposed to the air flow of the evaporator core.

Position the thermometer centrally in the loading space (e.g. suspend 1 m from the headlining using adhesive tape).
Read off and make a note of the loading space temperature.
Close the loading space doors.

Check

Start the engine.
Switch on the refrigeration system.
Set the temperature at the refrigeration system control assembly to 0°.
Raise the engine speed to 1500 rpm, maintain this engine speed and start the stopwatch.
Read off the loading space temperature at the thermometer again after 10 minutes.

Evaluation

The loading space temperature must be at least 6° C below the value of the initial measurement. Otherwise, the refrigerating capacity is insufficient and more extensive diagnosis of the refrigerant circuit must be performed.

Testing the Refrigerant Circuit

Workshop Equipment

The following equipment is required for the tests:

R-134a refrigerant center or set of R134a pressure gauges
Commercially available thermometer, measuring range at least: - 10° C to + 30° C

Pinpoint Test: Refrigerant Circuit

WARNING:The air conditioning systems is filled with refrigerant R134a. Observe "Health and Safety Precautions". For further information
REFER to: Gesundheits- und Sicherheitsvorkehrungen (100-00 Allgemeine Informationen, Description and Operation).

The following values must be determined:

Low pressure
High pressure
Ambient temperature at the vehicle

Test preparations

The following steps must be carefully followed to guarantee accurate test results.

WARNING:The manufacturer's instructions must be followed when connecting the R-134a refrigerant center or the set of R134a pressure gauges. Failure to observe this instruction can lead to injuries.

Connect the R134a refrigerant center or set of R134a pressure gauges to the refrigerant circuit.
Start the engine.
Switch on the refrigeration system.
Set the temperature at the refrigeration system control assembly to 0°.
Increase the engine speed to 1500 rpm and maintain this engine speed.

Test the system pressures

Take readings from the high and low pressure gauge and note the values.

Compare the obtained pressure values with the following specified values and use the symptom chart to determine the cause of the fault.

Target values

The high and low pressure values depend on the ambient temperature. The ambient temperature should be measured at a distance of 1 m from the vehicle.

The applicable tolerance range which describes the "normal" range for a measured value lies between the upper and lower curves.

High pressure

Co-ordinate axis	Description
1	High pressure (bar)
2	Ambient temperature (°C)

Low pressure

Co-ordinate axis	Description
1	Low pressure (bar)
2	Ambient temperature (°C)

Symptom Chart: Refrigeration System Refrigerant Circuit

NOTE:The following symptom chart provides an overview of possible fault profiles of the refrigerant circuit and the corresponding causes. The fault sources listed are examples and therefore do not represent specific diagnoses.

Symptom Chart: Refrigerant Circuit

Low pressure	High pressure	Source	Possible sources of fault
too low	too low	Insufficient refrigerant quantity	Insufficient refrigerant in the refrigerant circuit (e.g. owing to leakage) REFER to: Klimaanlage entleeren, evakuieren und befüllen (412-00 Innenraumklimatisierung - Allgemeine Informationen, General Procedures).
too low	normal or to too high	Insufficient refrigerant is fed to the evaporator core.	Expansion valve defective Refrigeration valve blocked/defective Drier/filter blocked High pressure line blocked
too low	normal or to too high	In some operating conditions (high engine speed, low refrigeration requirement at evaporator core) the quantity of refrigerant injected by the expansion valve may be so small that sufficient refrigerant supply (lubrication) to the compressor can only be ensured with the aid of the bypass controller. For further information, REFER to: Kühlanlage (412-05 Kühlanlage, Description and Operation).	Bypass controller inoperative: Bypass valve defective Bypass control pressure switch defective Relevant circuit faulty
too high	too low	Insufficient refrigerant compression ensues.	Compressor worn Compressor valves leaking Pressure accumulator blocked Low-pressure line blocked
too high	normal to too high	Too much refrigerant is fed to the evaporator core.	Expansion valve defective Defrost valve leaking
too high	too high	The refrigerant volume in the system is too high.	Radiator fan inoperative Condenser externally contaminated Condenser fins damaged Too much refrigerant in the refrigerant circuit

Mechanical Repairs
4 Electrical / 412 Climate Control System
412-05 Refrigeration
Description and Operation
Diagnosis and Testing
Refrigeration

General Procedures > < Refrigeration

Ford Workshop Service and Repair Manuals

Transit 2000.5 (01.2000-05.2006)

Mechanical Repairs 4 Electrical / 412 Climate Control System 412-05 Refrigeration Description and Operation Diagnosis and Testing Refrigeration

Mechanical Repairs 4 Electrical / 412 Climate Control System 412-05 Refrigeration Description and Operation Diagnosis and Testing Refrigeration

Mechanical Repairs
4 Electrical / 412 Climate Control System
412-05 Refrigeration
Description and Operation
Diagnosis and Testing
Refrigeration

Mechanical Repairs
4 Electrical / 412 Climate Control System
412-05 Refrigeration
Description and Operation
Diagnosis and Testing
Refrigeration