Diagnostic Aids
Important: The stop lamps will not illuminate unless the ignition is in the ON position. For more detailed information concerning stop lamp operation, refer to Exterior Lighting Systems Description and Operation .
Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Step | Action | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Exterior Lights Schematics Connector End View Reference: Master Electrical Component List | |||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |||||||
2 | Are all of the stop lamps inoperative? | Go to Step 3 | Go to Step 5 | ||||||
3 |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 9 | ||||||
4 |
Do the stop lamps illuminate? | Go to Step 8 | Go to Step 5 | ||||||
5 | Test the voltage supply circuit of the inoperative stop lamp for the following:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 6 | ||||||
6 | Test the ground circuit of the inoperative stop lamp for an open or high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 7 | ||||||
7 | Inspect for poor connections at the harness connector of the inoperative stop lamp or center high mounted stop lamp (CHMSL). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 13 | ||||||
8 | Inspect for poor connections at the stop lamp relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 12 | ||||||
9 | Test the stop lamp switch signal circuit for the following:
Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 10 | ||||||
10 | Inspect for poor connections at the harness connector of the instrument panel module (IPM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Step 14 | Go to Step 11 | ||||||
11 | Replace the IPM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 14 | -- | ||||||
12 | Replace the stop lamp relay. Refer to Relay Replacement . Did you complete the replacement? | Go to Step 14 | -- | ||||||
13 | Replace the inoperable stop lamp. Did you complete the replacement? | Go to Step 14 | -- | ||||||
14 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 | ||||||
