Output Diagnosis

Output Diagnosis Procedure

The control unit's circuitry can now also check the operation of certain components by generating specific output signals. This is the second part of the diagnosis procedure. To activate this part of the diagnosis procedure, a certain sequence must be followed. During the tests, the components can be checked by listening to see if they are operating. If a problem is found, first check the component's resistance with an ohmmeter for a short or open circuit before checking the wiring or control unit. Refer to the Repair Manual microfiche.

Output Diagnostic Codes:

1. Turn ignition off to erase the fault memory.

2. Turn ignition back on. Do not crank or start the engine. If this is done, the system will automatically switch to the input tests when the diagnosis procedure is activated.

3. Insert a spare fuse into the fuel pump relay for 4 seconds and then remove. The first step of the output tests will now be activated. There are five steps. To move to the next step reinsert the fuse into the relay again for 4 seconds.

The output check sequence will repeat starting again with step #1 when step #5 is completed.

Output diagnosis

Note: This diagnosis must be followed in order.

Work sequence
- switch ignition OFF to erase input signals from memory.

Part 1:

Part 2:

Note:
- If fuel pump relay or another component fails to operate during diagnosis, entire output diagnosis must be repeated after necessary repairs are made.

- Do not crank or start the engine during the output diagnosis. This would automatically switch the system to the input tests when the diagnosis procedure is activated.