Pinpoint Test K: The STOPLAMPS Are On Continuously

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

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: BCM-B C4368a.
- Do the stoplamps continue to illuminate?
- Yes : For the high mounted stoplamp, REPAIR circuit CLS17 (YE/GY) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  For the LH inboard stoplamp, REPAIR circuit CLS18 (GY/BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  
  For the LH middle stoplamp, REPAIR circuit CLS50 (BN/VT) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  
  For the LH outboard stoplamp, REPAIR circuit CLS51 (WH/GN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  
  For the RH inboard stoplamp, REPAIR circuit CLS19 (VT/OG) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  
  For the RH middle stoplamp, REPAIR circuit CLS52 (BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
  
  For the RH outboard stoplamp, REPAIR circuit CLS53 (GY/VT) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
- No : GO to K9.
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 . CLEAR the DTCs. REPEAT the self-test.
K4 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
- Yes : GO to K5.
- No : GO to K7.
K5 CHECK THE SJB
- Disconnect: SJB C2280b.
- Does the high mounted stoplamp continue to illuminate?
- Yes : GO to K6.
- No : GO to K8.
K6 CHECK FOR VOLTAGE ON THE STOPLAMP SWITCH OUTPUT CIRCUIT
- Disconnect: BCM-B C4368a.
- Measure the voltage between the BCM-B C4368a-19, circuit CCB08 (VT/WH), harness side and ground.
  
  Fig 1: Measuring Voltage Between BCM-B C4368A-19, Circuit CCB08 (VT/WH) And Ground
  Courtesy of FORD MOTOR CO.
- Is any voltage present?
- Yes : REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
- No : GO to K9.
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. REFER to ELECTRONIC ENGINE CONTROLS . 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.
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. REFER to MULTIFUNCTION ELECTRONIC MODULES . 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.
K9 CHECK FOR CORRECT BCM-B OPERATION
- Disconnect all the BCM-B connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the BCM-B 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 BCM-B. REFER to MULTIFUNCTION ELECTRONIC MODULES . 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.