Schematic Reference: Exterior Lights Schematics

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

Verify that the stoplamps are always on.

Do the stoplamps operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

Disconnect the stoplamp switch.

Do the stoplamps remain illuminated?

Go to Step 4

Go to Step 7

Disconnect the multifunction turn signal switch and the high mount stoplamp (CHMSL) relay (pickup only) and test for a short to voltage in the following circuits. Refer to Circuit Testing in Wiring Systems:

Was a problem found?

Go to Step 6

Go to Step 5

1. Test the CHMSL relay (pickup only) for shorted internal contacts and replace as necessary.
2. If the vehicle is not equipped with CHMSL relay or a relay fault is not found, replace the multifunction switch turn signal switch. Refer to Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle in Steering Wheel and Column - Standard or Multifunction, Turn Signal, and Hazard Switch Replacement - On Vehicle Steering Wheel and Column - Tilt.

Did you complete the repair?

Go to Step 8

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Repair the short to voltage in one of the following circuits. Refer to Wiring Repairs in Wiring Systems:

Did you complete the repair?

Go to Step 8

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Replace the stoplamp switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes.

Did you complete the repair?

Go to Step 8

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Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3