Pinpoint Test L: One Or More Stoplamps Are Inoperative

Stoplamps

Pinpoint Test L: One Or More Stoplamps Are Inoperative

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, voltage is supplied to the stoplamps through circuit CCB08 (VT/WH).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Rear lamp jumper harness

- High mounted stoplamp

- Rear window glass

PINPOINT TEST L : ONE OR MORE 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.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

L1 DETERMINE THE INOPERATIVE STOPLAMP

- Ignition OFF.

- Apply the brake pedal and observe the stoplamps.

Are all the stoplamps inoperative?

Yes
GO to Pinpoint Test K. Pinpoint Test K: All The Stoplamps Are Inoperative

No
For the high mounted stoplamp, GO to L2.

For a LH or RH rear stoplamp, GO to L5.

L2 CHECK THE HIGH MOUNTED STOPLAMP

- Remove the high mounted stoplamp. Refer to High Mounted Stoplamp .

- While applying the brake pedal, measure the voltage between the high mounted stoplamp pins on the rear window.





Is the voltage greater than 10 volts?

Yes
INSTALL a new high mounted stoplamp. REFER to High Mounted Stoplamp . TEST the system for normal operation.

No
GO to L3.

L3 CHECK THE STOPLAMP SWITCH OUTPUT CIRCUIT FOR AN OPEN (TO REAR WINDOW)

- Disconnect: High Mounted Stoplamp C475A.

- While applying the brake pedal, measure the voltage between the high mounted stoplamp C475A-1, circuit CCB08 (VT/WH), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to L4.

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

L4 CHECK THE HIGH MOUNTED STOPLAMP GROUND CIRCUIT FOR AN OPEN

- Disconnect: Negative Battery Cable.

- Disconnect: High Mounted Stoplamp C475B.

- Measure the resistance between the high mounted stoplamp C475B-1, circuit GD173 (BK), harness side and ground.





Is the resistance less than 5 ohms?

Yes
REPAIR or INSTALL a new rear window glass. TEST the system for normal operation.

No
REPAIR circuit GD173 (BK) for an open. TEST the system for normal operation.

L5 CHECK FOR VOLTAGE TO THE REAR LAMP JUMPER HARNESS

- Disconnect: Inoperative Rear Lamp.

- While applying the brake pedal, measure the voltage between the LH rear lamp C414-5, circuit CCB08 (VT/WH), harness side and ground; or between the RH rear lamp C417-5, circuit CCB08 (VT/WH), harness side and ground.





Is the voltage greater than 10 volts?

Yes
GO to L6.

No
REPAIR the circuit. TEST the system for normal operation.

L6 CHECK FOR VOLTAGE TO THE REAR LAMP JUMPER HARNESS USING THE CONNECTOR GROUND

- While applying the brake pedal, measure the voltage between the LH rear lamp C414-5, circuit CCB08 (VT/WH), harness side and the LH rear lamp C414-1, circuit GD149 (BK/GY), harness side; or between the RH rear lamp C417-5, circuit CCB08 (VT/WH), harness side and the RH rear lamp C417-1, circuit GD148 (BK/YE), harness side.





Is the voltage greater than 10 volts?

Yes
REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.

No
REPAIR circuit GD149 (BK/GY) (LH rear lamp) or circuit GD148 (BK/YE) (RH rear lamp) for an open. TEST the system for normal operation.