Pinpoint Test K: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Tests
Pinpoint Test K: The Stoplamps Are On Continuously
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB), the high mounted stoplamp, the PCM and the Battery Junction Box (BJB) fuse 82 (10A). The BJB fuse 82 (10A) then routes voltage to the Trailer Brake Control (TBC) module. When the SJB detects the brake pedal applied, the SJB provides voltage to the LH and RH rear stoplamps.
- DTC B1485 (Brake Pedal Input Short to Battery) - an on-demand DTC that sets when the SJB detects a short to voltage from the stoplamp switch input circuit.
- DTC B2045 (Left Rear Stop Lamp Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage from the LH rear stop/turn lamp output circuit.
- DTC B2047 (Right Rear Stop Lamp Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage from the RH rear stop/turn lamp output circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stoplamp switch
- TBC module
- PCM
- SJB
PINPOINT TEST K: THE STOPLAMPS ARE ON CONTINUOUSLY
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K1 DETERMINE IF ALL THE STOPLAMPS ARE ILLUMINATED
- Ignition OFF.
- Observe the stoplamps with the brake pedal released.
- Are all of the stoplamps illuminated?
Yes
GO to K3.
No
GO to K2.
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K2 CHECK THE SJB STOPLAMP OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280d.
- Do the stoplamps continue to illuminate?
Yes
If the LH rear lamp continues to illuminate, REPAIR circuit CLS18 (GY/BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
If the RH rear lamp continues to illuminate, REPAIR circuit CLS19 (VT/OG) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to K9.
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K3 CHECK THE STOPLAMP SWITCH
- Disconnect: Stoplamp Switch C278.
- Do the stoplamps continue to illuminate?
Yes
GO to K4.
No
INSTALL a new stoplamp switch. REFER to Stoplamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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K4 ISOLATE THE SHORT TO VOLTAGE
- Disconnect: BJB Fuse 82 (10A).
- Do the stoplamps continue to illuminate?
Yes
GO to K6.
No
If the vehicle is equipped with a TBC module, GO to K5.
If the vehicle is not equipped with a TBC module, REPAIR circuit CBB82 (GN) for a short to voltage. TEST the system for normal operation.
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K5 CHECK THE TBC MODULE
- Connect: BJB Fuse 82 (10A).
- Disconnect: TBC Module C2142.
- Do the stoplamps continue to illuminate?
Yes
REPAIR circuit CBB82 (GN) for a short to voltage. TEST the system for normal operation.
No
INSTALL a new TBC module. CLEAR the DTCs. REPEAT the self-test.
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K6 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
Yes
GO to K7.
No
GO to K8.
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K7 CHECK THE STOPLAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280b.
- Does the high mounted stoplamp continue to illuminate?
Yes
REPAIR circuit CCB08 (VT/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to K9.
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K8 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM 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 PCM. REFER to Computers and Control Systems. CLEAR the DTCs. REPEAT the self-test.
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.
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K9 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB 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. REFER to Body Control Systems. 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.
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