Querying failure memory (Mitsubishi Lancer 3)

If there is a defect in the MPI injection device, a warning lamp lights up on the dashboard. At the same time, the control unit switches to emergency mode and stores the detected defect. When the engine is off, the contents of the failure memory can be read. At service stations, a MITSUBISHI multi-tester is used for this. But this can also be done using an analog voltmeter or a LED tester.

Each memorized defect corresponds to a certain two-digit code. This code is indicated by longer or shorter bursts of the voltmeter needle. Longer bursts indicate the first digit of the code, and shorter ones indicate the second digit. There is a short pause between bursts. When using a LED tester, the LED blinks accordingly.

Note: The fault memory is erased if the battery ground is disconnected or the control unit connector is removed for more than 10 seconds.

Connect the voltmeter to terminals 1 (plus, +) and 12 (ground, -) of the diagnostic connector. The diagnostic connector is located on the left in the footwell next to the fuse box.

Turn on the ignition.

The voltmeter needle should briefly deflect.

Record the number of longer deviations as the first digit of the code. Then record the number of short deviations as the second digit of the code.

If the voltmeter needle deflects only once without returning to zero, then there is a defect in the control unit processor.

In the absence of longer deviations, there are no stored failures.

Example: The instrument needle deflected two times for a long time and three times for a short time, which gives a failure code 23. Failure 23 is stored when the control unit does not receive a voltage signal from the TDC sensor of cylinder 1.