10.4 CHECK ENGINE LIGHT AND STOP ENGINE LIGHT FAULT
The following steps will troubleshoot a fault with the check engine or stop engine lights. These
lights are used to alert the operator of engine faults; flash any trouble codes stored in the ECM;
and illuminate for five seconds and then go out during a start sequence, as a bulb check.
Perform the following to determine fault:
1. If the CEL or SEL is always on, refer to section 10.4.2.
2. If the CEL or SEL never lights, refer to section 10.4.5.
Display ECM Light Status
Perform the following steps to display light status:
1. While the light is lit, plug in the DDR (ignition ON).
2. Select switch light status.
3. View the displayed status for the problem light.
[a] If status reads OFF, refer to section 10.4.4.
[b] If status reads ON, refer to section 10.4.3.
Determine Reason for ECM Request
Perform the following steps to determine the reason the ECM is requesting the light to be ON:
1. Verify the diagnostic request is not ON.
[a] If the diagnostic request is ON, refer to section 10.10.
[b] If the diagnostic request is not ON, refer to section 9.1, (troubleshoot code).
Check for Grounded Wire
Perform the following steps to check for a grounded wire:
1. Turn ignition OFF.
2. Unplug VIH 30-pin connector.
3. Turn ignition ON.
[a] If the light stays on, drive (#509 or #419) wire is shorted to the ground. Repair or
replace the wire. Refer to section 10.4.9.
[b] If the light goes off, clean the connectors of the VIH 30-pin and assemble again.
Then, refer to section 10.4.9.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION