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. [1][2]Diagrams By Number

Normal Operation

The stoplamp switch is supplied voltage from the Smart Junction Box (SJB) fuse 2 (15A). When the brake pedal is applied, the stoplamp switch routes voltage to the stoplamps and the SJB (Smart Junction Box).

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- Stoplamp switch

- SJB (Smart Junction Box)

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 SBP02 (YE/RD), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to I2.

No
VERIFY the SJB (Smart Junction Box) fuse 2 (15A) is OK. If OK, GO to I3. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. [1][2]Diagrams By Number

I2 BYPASS THE STOPLAMP SWITCH

- Connect a fused jumper wire between the stoplamp switch C278-1, circuit SBP02 (YE/RD), harness side and the stoplamp switch C278-4, circuit CCB08 (VT/WH), harness side.





Do the stoplamps illuminate?

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.

I3 CHECK CIRCUIT SBP02 (YE/RD) FOR AN OPEN

- Disconnect: SJB (Smart Junction Box) C2280D.

- Measure the resistance between the stoplamp switch C278-1, circuit SBP02 (YE/RD), harness side and the SJB (Smart Junction Box) C2280D-13, circuit SBP02 (YE/RD), harness side.





Is the resistance less than 5 ohms?

Yes
GO to I4.

No
REPAIR SBP02 (YE/RD) for an open. TEST the system for normal operation.

I4 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION

- Disconnect all the SJB (Smart Junction Box) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the SJB (Smart Junction Box) 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 SJB (Smart Junction Box). 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. CLEAR the DTCs. REPEAT the self-test.