Reading and Clearing Diagnostic Trouble Codes

Fuel Pump Relay Location Fig. 27:

The fault memory can be called up by grounding terminal #4 of the control unit for at least 3 seconds. A special fuel pump relay is used to do this, Fig. 27. The relay is located in socket #10 of the fuse/relay panel. By inserting a spare fuse in the socket on top of the relay, terminal #4 will be grounded.
To extract the fault codes:
1. Switch ignition ON. Engine warning light in the instrument cluster should light.
2. Start the engine and rev once to at least 3000 rpm. Engine warning light should go out.
NOTE: If the engine warning light was ON while driving, and goes out at this point, the fault could be the ignition timing reaching full retard with detonation still being detected. Check ignition timing and then retest.
3. If engine warning light does not go out, install a fuse in the socket on top of the fuel pump relay for at least 3 seconds, then remove. Engine warning light should begin flashing.
4. If the engine warning light flashes a pattern of two flashes per interval, check:
a. Knock sensor torque*
b. Knock sensor wiring for open or short circuits
c. Defective knock sensor
d. Defective knock sensor control unit
5. If engine warning light flashes in a pattern of three flashes per interval, check:
a. White vacuum line to knock sensor control unit open or clogged
b. Pressure sensor in the control unit is faulty
c. Faulty throttle switches

Fig. 3 Type I and Type II Knock Sensors:

*Knock sensor installation torque is critical. If the knock sensor is over or under tightened, it will not work properly. To identify a type I or II knock sensor, see Fig. 3.
Type I ........... 10 - 12 Nm (7 - 9 ft. lb.)
Type II .......... 15 - 25 Nm (11 - 18 ft. lb.)