Front Light Failure

Front Light Failure

Fault symptoms
The SID unit gives a warning of front lamp failure despite no failure or does not give a warning despite a faulty lamp.

Diagnostic help
The front lamp failure input can be read using the diagnostics tool.
The message FRONT LIGHT FAILURE can be activated using the diagnostics tool.

Check the wiring harness
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short-circuits in the leads. Observe the multimeter, test lamp or diagnostics instrument during the test.

1. Check control module signal input
^ Remove component: front lamp filament monitor.





^ Connect the diagnostics tool to the vehicle and contact: SID.





^ Turn the ignition switch to ON.





^ Read status: front lamp broken.
^ The tester should show status: NO.

Test results OK?
YES
^ Go to point 2.
NO
^ Check the lead between terminal 9 of the relay holder and pin 23 of the control module for a short-circuit to ground, and repair or replace it.
^ Go to point 3.

2. Check the control module signal input (contd.)
^ Connect a jumper lead between terminal 9 of the relay holder and a good grounding point.





^ Read status: front lamp broken.
^ The tester should show status; YES.

Test results OK?
YES
^ Replace: front lamp filament monitor.
^ Go to point 3.
NO
^ Check the lead between terminal 9 of the relay holder and pin 23 of the control module for a short-circuit to ground, and repair or replace it.
^ Go to point 3.

3. Final check
^ Clear the diagnostic trouble codes in all systems.





^ Carry out a function check.





Test results OK?
YES
^ The steps taken to rectify the fault were correct.
^ See "Before changing a control module." Before Changing A Control Module