Pinpoint Test I: All The Stoplamps Are Inoperative

Stoplamps

Pinpoint Test I: All The Stoplamps Are Inoperative

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

Normal Operation

The stoplamp switch is supplied voltage from the Battery Junction Box (BJB). When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB) and the high mounted stoplamp.

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- Stoplamp switch

PINPOINT TEST I : ALL THE STOPLAMPS ARE INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

I1 CHECK FOR VOLTAGE TO THE STOPLAMP SWITCH

- Ignition OFF.

- Disconnect: Stoplamp Switch C278.

- Measure the voltage between the stoplamp switch C278-1, circuit SBB14 (BN/RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to I2.

No
VERIFY the BJB (Battery Junction Box) fuse 14 (10A) is OK. If OK, REPAIR circuit SBB14 (BN/RD) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Electrical Diagrams

I2 BYPASS THE STOPLAMP SWITCH

- Connect a fused jumper wire between the stoplamp switch C278-1, circuit SBB14 (BN/RD), harness side and the stoplamp switch C278-4, circuit CCB08 (VT/WH), harness side.





Are the stoplamps illuminated?

Yes
REMOVE the jumper wire. INSTALL a new stoplamp switch. REFER to Stoplamp Switch . TEST the system for normal operation.

No
REMOVE the jumper wire. REPAIR circuit CCB08 (VT/WH) for an open. TEST the system for normal operation.