Pinpoint Test I: All The Stoplamps Are Inoperative

Stoplamps

Pinpoint Test I: All The Stoplamps Are Inoperative

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

Normal Operation

The stoplamp switch is supplied voltage at all times from the Battery Junction Box (BJB). When the brake pedal is applied, the stoplamp switch closes and 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 THE BRAKE PEDAL POSITION SWITCH VOLTAGE SUPPLY CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Stoplamp Switch C278.

- Measure the voltage between the stoplamp switch C278-1, circuit SBB43 (BU/RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to I2.

No
VERIFY the BJB (Battery Junction Box) fuse 43 (5A) is OK. If OK, REPAIR circuit SBB43 (BU/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 SBB43 (BU/RD), harness side and the stoplamp switch C278-4, circuit CLS17 (YE/GY), 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 CLS17 (YE/GY) for an open. TEST the system for normal operation.