Pinpoint Test K: The Stoplamps Are On Continuously

Stoplamps

Pinpoint Test K: The Stoplamps Are On Continuously

Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information Electrical Diagrams.

When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB), the high mounted stoplamp, and the PCM. When the SJB (Smart Junction Box) detects the brake pedal is applied, the SJB (Smart Junction Box) provides voltage to the LH and RH rear stoplamps. 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 (Smart Junction Box) 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 (Smart Junction Box) detects a short to voltage from the LH rear stop/turn lamp voltage supply circuit.

- DTC B2047 (Right Rear Stoplamp Circuit Open)- an on-demand DTC that sets when the SJB (Smart Junction Box) detects a short to voltage from the RH rear stop/turn lamp voltage supply circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Stoplamp switch

- PCM

- SJB (Smart Junction Box)

PINPOINT TEST K : THE STOPLAMPS ARE ON CONTINUOUSLY

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.

K2 CHECK THE STOPLAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: SJB (Smart Junction Box) 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. TEST the system for normal operation.

If the RH rear lamp continues to illuminate, REPAIR circuit CLS19 (VT/OG) for a short to voltage. TEST the system for normal operation.

No
GO to K7.

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 . TEST the system for normal operation.

K4 CHECK THE PCM

- Disconnect: PCM C175B.

Do the stoplamps continue to illuminate?

Yes
GO to K5.

No
GO to K6.

K5 CHECK THE STOPLAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE

- Disconnect: SJB (Smart Junction Box) C2280B.

Does the high mounted stoplamp continue to illuminate?

Yes
REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.

No
GO to K7.

K6 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. 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.

K7 CHECK FOR CORRECT SJB (Smart Junction Box) OPERATION

- Disconnect all the SJB (Smart Junction Box) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the SJB (Smart Junction Box) 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 (Smart Junction Box). 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.