DME System 1 (Code 1223)

Engine Management: Motronic Control Unit 1 (DME/EML 1.7):

1. With the ignition switch in the "OFF" position, disconnect the coolant temperature sensor connector X6236 (located at the rear of the right cylinder bank).

Fig. 25 Coolant Temperature Sensor Location:

2. Turn the ignition switch to the run position and make the following voltage measurements at connector X6236 (female side).

^ Brown/red/yellow wire (terminal 1) and ground = approx. 5 volts. If not check wire to terminal 78 of the Digital Motor Electronic (DME) control unit harness connector (X6010), for an open or short to voltage or ground. If wire is OK, the DME control unit is defective.
^ Brown/red/yellow (terminal 1) and brown (terminal 2) = approx. 5 volts. If the reading is incorrect, check wire to ground for an open.
^ If all voltages are correct continue with step 3.

3. With the ignition switch in the OFF position, clear the DME control unit memory by disconnecting the DME control unit harness connector X6010. Reconnect the control unit harness connector.
4. Install a new coolant temperature sensor.
5. Start the engine and warm it up to normal operating temperature, varying the load conditions.

^ If the check engine light remains off, retain the new coolant temperature sensor. End of test.
^ If the "Check Engine" light illuminates, repeat the self diagnostic procedures in "EXTRACTING FAULT CODES".
^ If a code 1223 is present the DME control unit is defective.