Fault Tracing

FAULT TRACING AND TYPES OF FAULT.

A1

FAULT TYPE 1:
ECC SYSTEM STUCK IN THE MAX. POSITION FOR EITHER HOT OR COLD OR HAS SOME OTHER EXTREME FAULT.

CAUSE:

External electrical interference can have affected the program.

ANALYSIS METHOD:

Interference continues until the ignition is turned off. When the ignition is again activated the program resets and performs normally.

If DTCs 321, 322, 323, or 324 are posted and no fault can be detected, the control system can be malfunctioning due to interference.

REPAIRS:

By applying a 5 V current to pins 3 and 4 in the control module 10-pin connector according to the method described in this Service Bulletin. (see section B) the control module will not be affected by external electronic interference.

Carry out operations in section B or D.

A2

FAULT TYPE 2:

The blower motor suddenly stops or does not start.

CAUSE A:

The control program is not affected by external electrical interference but the blower motor is using too much power.

There is an integral overload protection in the power stage which breaks the circuit to the blower motor if the power consumption exceeds 35 amps. The overload device resets when the ignition is switched off.

ANALYSIS METHOD:

The blower motor consumption must not exceed 27 amps at constant speed on the max. speed.

REPAIRS:

Refer to Service Manual at CR. Refer to section D.

CAUSE B:

The power stage overload breaks the circuit when the supply is too low.

ANALYSIS METHOD:

^ Refer to Service Manual at CX.

REPAIRS:

^ Perform operations at CX according to Service Manual. Then carry out operations at D.

A3

FAULT TYPE 3: THE IN-CAR TEMP. SENSORS REGISTERED THE WRONG TEMPERATURE.

CAUSE:

The grilles in the headliner are not in the correct position in relation to the sensors.

Can only occur on 854 cars with chassis numbers up to and including 046285 fitted with the older sensor type.

ANALYSIS METHOD:

Check the position of the grilles in the headliner in relation to the sensors so that they are directly in front of the center of the sensors and that the headliner is up against the foam seal on the sensors.

Press in the foam seal round the entire sensor to ensure a complete and good seal. (Refer to Service Manual at section SB.)

REPAIRS:

If one or both grilles are incorrectly positioned or if the sealing is not
complete then the sensors and grilles should be replaced with the latest versions to ensure correct in-car temperature registration.

Then carry out operations at D.

A4

FAULT TYPE 4: INCORRECT SETTING ON CONTROLS

CAUSE A:

Closed dash vents and Air-mix open.

ANALYSIS METHOD:

Check if the control setting Is correct. Owner/driver can have set the controls incorrectly.

REPAIRS:

Inform customer that driving with closed dash vents and open Air-mix
results in incorrect air-flow in the ECC climate unit with resulting control function error. This is similar to that obtained from electrical interference.

REMARK:

If the Air-mix is open the center dash vents must always be fully open. Then carry out operations at 0.

CAUSE B:

Completely closed outer dash vents result in the ECC unit reacting slowly.

ANALYSIS METHOD:

Check if the control setting is correct.

REPAIRS:

The dash vents should never be completely closed. Open them slightly. Then carry out operations at 0.