Pinpoint Test M: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Tests
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) through circuit SBP02 (YE/RD). When the brake pedal is applied, the stoplamp switch routes voltage through circuit CCB08 (VT/WH).
On vehicles without adaptive cruise control, the voltage is supplied directly to the stoplamps through circuit CCB08 (VT/WH).
On vehicles with adaptive cruise control, the voltage is routed to the adaptive cruise control relay (controlled by the Cruise-Control Module (C-CM)) through circuit CCB08 (VT/WH). The voltage passes through the relay to circuit CLS43 (YE/GN) which then routes to voltage to the stoplamps through circuit CCB08 (VT/WH). The C-CM 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 SJB and the PCM.
- 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 output circuit.
- DTC C1105:11 (Brake Lamp Control: Circuit Short To Ground) - a continuous and on-demand DTC that sets when the C-CM detects a short to voltage from the adaptive cruise control stoplamp relay voltage supply circuit.
- DTC P1571:12 (Brake Switch: Circuit Short To Battery) - an on-demand DTC that sets when the RFA 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
- C-CM module
- RFA module
- SJB
- PCM
PINPOINT TEST M: THE STOPLAMPS ARE ON CONTINUOUSLY
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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 Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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M2 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
Yes
GO to M3.
No
GO to M9.
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M3 CHECK THE SJB
- Disconnect: SJB 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.
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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, 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.
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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 87A, circuit CCB08 (VT/WH), BJB 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.
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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.
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M7 CHECK CIRCUIT CLS44 (VT/BN) FOR A SHORT TO GROUND
- Disconnect: C-CM C3173.
- Measure the resistance between the adaptive cruise control stoplamp relay pin 86, circuit CLS44 (VT/BN), BJB face side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to M11.
No
REPAIR the circuit. TEST the system for normal operation.
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M8 CHECK THE RFA MODULE FOR A SHORT TO VOLTAGE
- Disconnect: RFA Module C2153d.
- 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.
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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.
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M10 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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M11 CHECK FOR CORRECT C-CM OPERATION
- Disconnect the C-CM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the C-CM 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 C-CM. 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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M12 CHECK FOR CORRECT RFA MODULE OPERATION
- Disconnect all the RFA module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the RFA 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 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.
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