DME System 2

Injection Electronics (Motronic Control Unit II). Wiring Diagram:

1. If a code 2221 or 2222 is present, cancel the DME fault code memory after noting all other existing codes.
2. Start the engine and warm it up to normal operating temperature. Drive the vehicle varying the load conditions. If the "Check Engine" light does not illuminate the problem is intermittent. If the "Check Engine" light does illuminate and a fault code 2221 or 2222 is present continue with step 3.

3. With the ignition switch in the OFF position, disconnect the oxygen sensor in-line connector X1564 (located under the vehicle). NOTE The connector is located on the right side with a red band around the wire harness.
4. Turn the ignition switch to the run (ON) position and make the following voltage measurements at connector X1564 (female half).

^ Black wire (terminal 2) and ground = approx. 0.65 volts
^ Black (terminal 2) and yellow wire (terminal 1) = approx. 0.45 volts

5. Turn the ignition switch OFF and measure between

^ Black (terminal 2) and yellow wire (terminal 1) = 0 volts
^ If all voltages are correct, continue with step 6.
^ If any voltages are incorrect, check wires to terminals 28 and 10 of the DME control unit harness connector X1601 (disconnected) for an open or short to ground. If the wires are OK, the DME control unit is defective.

6. Check the following items for operation and repair or replace as necessary. If no problems are found continue with step 7.


RUNNING RICH RUNNING LEAN

^ Engine oil diluted with fuel ^ Air leak at crankcase vent hose
^ Operation of the purge valve ^ Air leak at the idle control valve hoses
^ Operation of the charcoal canister ^ Air leak at the rubber boot between the air mass meter and throttle housing
^ Operation of the DME main relay ^ Air leak at injector rubber sealing rings
^ Operation of the fuel pump relay ^ Clogged injectors
^ Stuck open injectors ^ Insufficient fuel pressure
^ Operation of the of the fuel pressure regulator ^ Bad fuel (water in fuel)

7. With the ignition switch OFF, replace the oxygen senor.
8. Start the engine and warm it up to normal operating temperature. Drive the vehicle varying the load conditions. If the "Check Engine" light does not illuminate retain the new oxygen sensor. If the "Check Engine" light does illuminate and a fault code 2221 or 2222 is present the DME control unit is defective.