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 Trailer Brake Control (TBC) module (if equipped), and the PCM through circuit CCB08 (VT/WH). When the SJB detects the brake pedal applied, the SJB provides voltage to the LH and RH rear stoplamps through circuits CLS18 (GY/BN) and CLS19 (VT/OG), respectively. If equipped with trailer tow, voltage is also supplied to the respective trailer tow stop/turn relay.
- 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 on the LH rear stop/turn lamp voltage supply circuit.
- DTC B2047 (Right Rear Stop Lamp Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage on the RH rear stop/turn lamp voltage supply 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 STOPLAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280d.
- Do the stoplamps continue to illuminate?
Yes
REPAIR circuit CLS18 (GY/BN) (LH rear lamp) or circuit CLS19 (VT/OG) (RH rear lamp) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to K8.
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K3 CHECK THE STOPLAMP SWITCH
- Disconnect: Stoplamp Switch C278.
- Do the stoplamps continue to illuminate?
Yes
If equipped with a TBC module, GO to K4.
If not equipped with a TBC module, GO to K5
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 CHECK THE TBC
- Disconnect: TBC Module C2142.
- Do the stoplamps continue to illuminate?
Yes
GO to K5.
No
INSTALL a new TBC module. CLEAR the DTCs. REPEAT the self-test.
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K5 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
Yes
GO to K6.
No
GO to K7.
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K6 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 K8.
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K7 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. 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.
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K8 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. 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.
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