Test point

Activation of AC relay Using the System Tester 9288, activation of the AC relay may be

Fault code 1 29 checked directly in the Drive links menu item.

If no sound is audible, check the following: 1) AC switch signal:

DME plug disconnected, ignition on, connect voltmeter between terminal 40 and terminal 24. AC switch on: Display approx. 12 Volt If not: Check in accordance with wiring diagram If the air conditioning system is inoperative, the fault may be due to the 115° C coolant temperature switch. To check the switch, connect ohmmeter with terminal 41 of the disconnected control unit plug and ground. Ignition on. Display: <»Q

If not, check in accordance with wiring diagram

2) Voltage at A/C relay:

Connect DME plug. Remove A/C relay (G19) from Central Electrical

System. Connect voltmeter with relay base terminal 2 and terminal 7.

Operate A/C switch with engine running.

Display: Battery voltage after approx. 5 seconds

No display: Check wiring between A/C relay and DME control unit.

Test point 14 Knock sensor 1

Fault code 1 31 - Mounting of knock sensor (observe torque and type of screw)

- Check wiring harness and plug connection in accordance with wiring diagram

- Reconnecting the plugs helps to eliminate contact resistances

- Check if coolant or other fluids have ingressed in the knock sensor area

- Replace knock sensor

If the knock sensor is faulty, ignition timing Is retarded by 6° on the crankshaft at a certain engine load.

Fault, Fault Code

Possible Causes, Elimination, Remarks

Test point 15 Knock sensor II

Fault code 1 32

- Mounting of knock sensor (observe torque and type of screw)

- Check wiring harness and plug connections in accordance with wiring diagrams

- Reconnecting the sensors helps to eliminate contact resistances

- Check if coolant or other fluids have ingressed in the knock sensor area

- Replace knock sensor

If the knock sensor is faulty, ignition timing is retarded by 6° on the crankshaft

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

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