Pinpoint Test K: The Stoplamps Are On Continuously
Stoplamps
Pinpoint Tests
Pinpoint Test K: 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 - Taurus, Taurus X
When the brake pedal is applied, the stoplamp switch routes voltage to the Smart Junction Box (SJB), the PCM and the high mounted stoplamp through circuit CCB08 (VT/WH). The SJB then provides voltage to the LH and RH rear lamps through circuits CLS18 (GY/BN) and CLS19 (VT/OG).
Sable
When the brake pedal is applied, the stoplamp switch routes voltage to the SJB, the PCM, the rear lamps, and the high mounted stoplamp through circuit CCB08 (VT/WH).
- 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.
- DTC B2045 (Left Rear Stop Lamp Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage on the LH rear stop/turn lamp voltage supply circuit.
- DTC B2047 (Right Rear Stop Lamp Circuit Open) - an on-demand DTC that sets when the SJB detects a short to voltage on the RH rear stop/turn lamp voltage supply circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Stoplamp switch
- PCM
- SJB
PINPOINT TEST K: THE STOPLAMPS ARE ON CONTINUOUSLY
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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.
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K2 CHECK THE STOPLAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280d.
- Do the stoplamps continue to illuminate?
Yes
If the LH rear lamp continues to illuminate, REPAIR circuit CLS18 (GY/BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
If the RH rear lamp continues to illuminate, REPAIR circuit CLS19 (VT/OG) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to K7.
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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 Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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K4 CHECK THE PCM
- Disconnect: PCM C175b.
- Do the stoplamps continue to illuminate?
Yes
GO to K5.
No
GO to K6.
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K5 CHECK THE STOPLAMP SWITCH OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: SJB C2280b.
- Does the high mounted stoplamp continue to illuminate?
Yes
REPAIR circuit CCB08 (VT/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to K7.
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K6 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. 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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K7 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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