Pinpoint Test L: One Or More Stoplamps Are Inoperative
Stoplamps
Pinpoint Tests
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. Refer to Battery.
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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.
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L2 CHECK THE HIGH MOUNTED STOPLAMP
- Remove the high mounted stoplamp. Refer to High Mounted Stoplamp Service and Repair.
- 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 Service and Repair. TEST the system for normal operation.
No
GO to L3.
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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.
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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. REFER to Windows and Glass. TEST the system for normal operation.
No
REPAIR circuit GD173 (BK) for an open. TEST the system for normal operation.
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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.
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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.
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