Pinpoint Test K: The Stoplamps Are On Continuously

Stoplamps

Pinpoint Tests

Pinpoint Test K: The Stoplamps Are On Continuously

Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number

Normal Operation

When the brake pedal is applied, the stoplamp switch routes voltage to the stoplamps and the PCM.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Stoplamp switch
- PCM


PINPOINT TEST K: THE STOPLAMPS ARE ON CONTINUOUSLY

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K1 CHECK THE STOPLAMP SWITCH


- Disconnect: Stoplamp Switch C278.
- Do the stoplamps continue to illuminate?

Yes
GO to K2.

No
INSTALL a new stoplamp switch. REFER to Stoplamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.

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K2 CHECK THE PCM


- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?

Yes
REPAIR the stoplamp switch output circuit for a short to voltage. TEST the system for normal operation.

No
GO to K3.

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K3 CHECK FOR CORRECT PCM OPERATION


- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. TEST the system for normal operation.

No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.

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