Pinpoint Test M: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Test M: The Stoplamps Are On Continuously
Normal Operation
The stoplamp switch is supplied voltage from the Battery Junction Box (BJB).
When the brake pedal is applied on vehicles without adaptive cruise control, voltage is supplied directly to the stoplamps.
When the brake pedal is applied on vehicles with adaptive cruise control, voltage is routed to the adaptive cruise control relay (controlled by the ABS module). The voltage passes through the relay to the stoplamps. The ABS module energizes the adaptive cruise control stoplamp relay by providing voltage to the relay coil.
When the brake pedal is applied, voltage is also routed to the Remote Function Actuator (RFA) module, the Smart Junction Box (SJB) and the PCM.
- 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 output circuit.
- DTC C1105 (Traction Control Disable Lamp Circuit Short To Battery)- sets when the ABS module detects a short to ground from the adaptive cruise control stoplamp relay coil ground supply circuit during an ignition cycle from OFF to ON.
- DTC P1571:12 (Brake Switch: Circuit Short To Battery)- an on-demand DTC that sets when the RFA (Remote Function Actuator) detects a short to voltage from the stoplamp switch output circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Adaptive cruise control stoplamp relay (if equipped)
- Stoplamp switch
- ABS (Anti-Lock Brake System) module
- RFA (Remote Function Actuator) module
- BJB (Battery Junction Box)
- PCM
PINPOINT TEST M : THE STOPLAMPS ARE ON CONTINUOUSLY
M1 CHECK THE STOPLAMP SWITCH
- Disconnect: Stoplamp Switch C278.
Do the stoplamps continue to illuminate?
Yes
GO to M2.
No
INSTALL a new stoplamp switch. REFER to Stoplamp Switch . CLEAR the DTCs. REPEAT the self-test.
M2 CHECK THE PCM
- Disconnect: PCM C175B.
Do the stoplamps continue to illuminate?
Yes
GO to M3.
No
GO to M9.
M3 CHECK THE SJB (Smart Junction Box)
- Disconnect: SJB (Smart Junction Box) C2280B.
Do the stoplamps continue to illuminate?
Yes
If equipped with adaptive cruise control, GO to M4.
If not equipped with adaptive cruise control, REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
No
GO to M10.
M4 CHECK THE ADAPTIVE CRUISE CONTROL STOPLAMP RELAY OUTPUT
- Disconnect: Adaptive Cruise Control Stoplamp Relay.
Do the stoplamps continue to illuminate?
Yes
If equipped with Intelligent Access (IA), GO to M8.
If not equipped with IA (Intelligent Access), REPAIR circuit CCB08 (VT/WH) or circuit CLS43 (YE/GN) for a short to voltage. TEST the system for normal operation.
No
GO to M5.
M5 CHECK THE STOPLAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (TO ADAPTIVE CRUISE CONTROL STOPLAMP RELAY)
- Measure the voltage between the adaptive cruise control stoplamp relay pin 4, circuit CCB08 (VT/WH), BJB (Battery Junction Box) face side and ground.
Is any voltage present?
Yes
REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
No
GO to M6.
M6 CHECK THE ADAPTIVE CRUISE CONTROL STOPLAMP RELAY
- Substitute a known good relay.
Do the stoplamps continue to illuminate?
Yes
REMOVE the known good relay. GO to M7.
No
REMOVE the known good relay. INSTALL a new adaptive cruise control stoplamp relay. TEST the system for normal operation.
M7 CHECK THE STOPLAMP SWITCH FOR A SHORT TO GROUND (TO ADAPTIVE CRUISE CONTROL STOPLAMP RELAY)
- Disconnect: ABS Module C135.
- Measure the resistance between the adaptive cruise control stoplamp relay pin 1, circuit CLS44 (VT/BN), BJB (Battery Junction Box) face side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to M11.
No
REPAIR circuit CLS44 (VT/BN) for a short to ground. TEST the system for normal operation.
M8 CHECK THE RFA (Remote Function Actuator) MODULE FOR A SHORT TO VOLTAGE
- Disconnect: RFA (Remote Function Actuator) Module C2153E.
Do the stoplamps continue to illuminate?
Yes
REPAIR circuit CCB08 (VT/WH) or circuit CLS43 (YE/GN) for a short to voltage. TEST the system for normal operation.
No
GO to M12.
M9 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.
M10 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.
M11 CHECK FOR CORRECT ABS MODULE OPERATION
- Disconnect the ABS module connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the ABS module connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new ABS module. 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.
M12 CHECK FOR CORRECT RFA (Remote Function Actuator) MODULE OPERATION
- Disconnect all the RFA (Remote Function Actuator) module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RFA (Remote Function Actuator) module 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 RFA (Remote Function Actuator) module. 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.