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 routed to the stoplamps.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Rear lamp jumper harness
- High mounted stoplamp
- Rear lamp assembly
- 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.
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L1 DETERMINE THE INOPERATIVE STOPLAMP
- Ignition OFF.
- Apply the brake pedal and observe the stoplamps.
- Is the high mounted stoplamp illuminated?
Yes
GO to L5.
No
GO to L2.
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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 C414-3, circuit CCB08 (VT/WH), harness side and ground; or between the RH rear lamp C417-3, circuit CCB08 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to L6.
No
REPAIR circuit CCB08 (VT/WH) for an open. 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 C414-3, circuit CCB08 (VT/WH), harness side and the LH rear lamp C414-1, circuit GD148 (BK/YE), harness side; or between the RH rear lamp C417-3, circuit CCB08 (VT/WH), harness side and the RH rear lamp C417-1, circuit GD149 (BK/GY), harness side.
- Is the voltage greater than 10 volts?
Yes
GO to L7.
No
REPAIR the ground circuit in question for an open. TEST the system for normal operation.
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L7 CHECK THE REAR LAMP JUMPER HARNESS
- Inspect the rear lamp jumper harness for opens.
- Is the rear lamp jumper harness OK?
Yes
INSTALL a new rear lamp assembly. REFER to Rear Lamp Assembly Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.
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