Check Engine Lamp (MIL)

CHECKING THE CHECK ENGINE LAMP (MIL)
1. With the ignition switched OFF, connect a BOB to the MOTRONIC control module.
With the ignition switch in the Drive position, check that the CHECK ENGINE lamp lights up when a jumper lead is connected between pins 14 and 21.

If it does not, check that the lamp is supplied with voltage and connected to ground.
Also check the lead and connector between pin 21 of the control module and the lamp for continuity.

2. The CHECK ENGINE lamp should light up when the control module grounds pin 21 if a diagnostic trouble code has been generated, or always when the ignition is switched ON.
Measure the voltage across pins 37 and 21 on the BOB. Battery voltage should be present when the ignition is switched ON.

If it is not, continue at "Before Control Module Replacement" for further diagnostic instructions. Before Replacing A Control Module