Pinpoint Test L: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Tests
Pinpoint Test L: The Stoplamps Are On Continuously
Refer to Wiring Diagram Set 90, Turn Signal/Stop/Hazard Lamps for schematic and connector information. Diagrams By Number
Normal Operation - Fusion
When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB) through circuit CCB08 (VT/WH). The voltage is then routed out of the SJB to the high mounted stoplamp through circuit CLS17 (YE/GY). The SJB also supplies voltage to the LH and RH rear stoplamps through circuit CLS18 (GY/BN) and circuit CLS19 (VT/OG).
Milan, MKZ
When the brake pedal is applied, the stoplamp switch routes voltage to the SJB through circuit CCB08 (VT/WH). The voltage is then routed out of the SJB to the stoplamps through circuit CLS17 (YE/GY).
The rear lamps contain electronics that modulate the voltage frequency to the LED bulbs.
- 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 input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stoplamp switch
- SJB
- PCM
PINPOINT TEST L: THE STOPLAMPS ARE ON CONTINUOUSLY
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L1 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 L2.
No
GO to L6.
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L2 CHECK THE STOPLAMP SWITCH
- Disconnect: Stoplamp Switch C278.
- Do the stoplamps continue to illuminate?
Yes
GO to L3.
No
INSTALL a new stoplamp switch. REFER to Stoplamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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L3 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
Yes
GO to L4.
No
GO to L8.
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L4 CHECK CIRCUIT CCB08 (VT/WH) FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280a.
- Do the stoplamps continue to illuminate?
Yes
For Fusion, GO to L5.
For Milan or MKZ, GO to L7.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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L5 CHECK THE SJB
- Disconnect: SJB C2280c.
- Do the stoplamps continue to illuminate?
Yes
GO to L6.
No
GO to L9.
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L6 CHECK THE STOPLAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280e.
- Do the stoplamps continue to illuminate?
Yes
If the high mounted stoplamp continues to illuminate, REPAIR circuit CLS17 (YE/GY). CLEAR the DTCs. REPEAT the self-test.
If the LH rear lamp continues to illuminate, REPAIR circuit CLS18 (GY/BN). CLEAR the DTCs. REPEAT the self-test.
If the RH rear lamp continues to illuminate, REPAIR circuit CLS19 (VT/OG). CLEAR the DTCs. REPEAT the self-test.
No
GO to L9.
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L7 CHECK CIRCUIT CLS17 (YE/GY) FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280e.
- Do the stoplamps continue to illuminate?
Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
No
GO to L9.
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L8 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 Computers and Control Systems Information. 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. CLEAR the DTCs. REPEAT the self-test.
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L9 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 Body Control Systems. 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.
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