Pinpoint Test M: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Test M: The Stoplamps Are On Continuously
Refer to Wiring Diagram Set 11, Fuse and Relay Information for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The stoplamp switch is supplied voltage from the Smart Junction Box (SJB).
When the brake pedal is applied on vehicles without adaptive cruise control, the voltage is supplied directly to the PCM, the SJB (Smart Junction Box) and the stoplamps.
When the brake pedal is applied on vehicles with adaptive cruise control, the voltage is routed to the PCM and then to the adaptive cruise control stoplamp relay (located in the Battery Junction Box (BJB)). The voltage passes through the relay which is then routed to the SJB (Smart Junction Box), the Remote Function Actuator (RFA) module (if equipped with Intelligent Access (IA) and the stoplamps.
- 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) module 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
- Stoplamp switch
- ABS module
- RFA (Remote Function Actuator) module
- SJB (Smart 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
If equipped with adaptive cruise control, GO to M2.
If not equipped with adaptive cruise control, GO to M7.
No
INSTALL a new stoplamp switch. REFER to Stoplamp Switch . CLEAR the DTCs. REPEAT the self-test.
M2 CHECK THE ADAPTIVE CRUISE CONTROL STOPLAMP RELAY OUTPUT
- Disconnect: Adaptive Cruise Control Stoplamp Relay.
Do the stoplamps continue to illuminate?
Yes
GO to M7.
No
GO to M3.
M3 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 M4.
No
REMOVE the known good relay. INSTALL a new adaptive cruise control stoplamp relay. TEST the system for normal operation.
M4 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 CLS43 (YE/GN), BJB (Battery Junction Box) face side and ground.
Is any voltage present?
Yes
GO to M5.
No
GO to M6.
M5 CHECK THE PCM (VEHICLES WITH ADAPTIVE CRUISE CONTROL)
- Disconnect: PCM C175B or C1381B.
- Measure the voltage between the adaptive cruise control stoplamp relay pin 4, circuit CLS43 (YE/GN), BJB (Battery Junction Box) face side and ground.
Is any voltage present?
Yes
REPAIR circuit CLS43 (YE/GN) for a short to voltage. TEST the system for normal operation.
No
GO to M10.
M6 CHECK THE ADAPTIVE CRUISE CONTROL STOPLAMP RELAY COIL CIRCUIT FOR A SHORT TO GROUND
- Disconnect: ABS Module C135.
- Measure the resistance between the adaptive cruise control stoplamp relay pin 1, circuit CCA28 (GY/BN), BJB (Battery Junction Box) face side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to M12.
No
REPAIR circuit CCA28 (GY/BN) for a short to ground. TEST the system for normal operation.
M7 CHECK THE SJB (Smart Junction Box)
- Disconnect: SJB (Smart Junction Box) C2280B.
Do the stoplamps continue to illuminate?
Yes
If equipped with IA (Intelligent Access), GO to M8.
If not equipped with IA (Intelligent Access) but equipped with adaptive cruise control, REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
If not equipped with IA (Intelligent Access) or adaptive cruise control, GO to M9.
No
GO to M11.
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
If equipped with adaptive cruise control, REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
If not equipped with adaptive cruise control, GO to M9
No
GO to M13.
M9 CHECK THE PCM (VEHICLES WITHOUT ADAPTIVE CRUISE CONTROL)
- Disconnect: PCM C175B or C1381B.
Do the stoplamps continue to illuminate?
Yes
REPAIR circuit CCB08 (VT/WH) for a short to voltage. TEST the system for normal operation.
No
GO to M10.
M10 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.
M11 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.
M12 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.
M13 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.