DI/APC System Diagnostics With Lamp Flash Codes

On-board diagnostics with Lamp-flash codes

With the ignition switched on and the engine switched oft, the CHECK ENGINE lamp (M90-) will come on for only about 2 seconds. If there is a fault in the system, the CHECK ENGINE lamp will flash a code.

When the engine is started, the CHECK ENGINE lamp will remain on if a permanent fault is present. If a fault arises while the car is being driven (temporary fault), the CHECK ENGINE lamp will remain on as long as the fault persists but will go out when the fault disappears. However, the fault will be stored in memory and a readout of it can be obtained with the engine turned off and the ignition switched on.