Pinpoint Test I: All The Stoplamps Are Inoperative
Stoplamps
Pinpoint Test I: All The Stoplamps Are Inoperative
Refer to Wiring Diagram Set 90 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), 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) fuse 2 (15A). When the brake pedal is applied, the stoplamp switch routes voltage to the stoplamps and the SJB.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Stoplamp switch
- SJB
PINPOINT TEST I: ALL THE STOPLAMPS ARE INOPERATIVE
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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I1 CHECK FOR VOLTAGE TO THE STOPLAMP SWITCH
- Ignition OFF.
- Disconnect: Stoplamp Switch C278.
- Measure the voltage between the stoplamp switch C278-1, circuit SBP02 (YE/RD), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to I2.
No
VERIFY the SJB fuse 2 (15A) is OK. If OK, GO to I3. TEST the system for normal operation. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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I2 BYPASS THE STOPLAMP SWITCH
- Connect a fused jumper wire between the stoplamp switch C278-1, circuit SBP02 (YE/RD), harness side and the stoplamp switch C278-4, circuit CCB08 (VT/WH), harness side.
- Do the stoplamps illuminate?
Yes
REMOVE the jumper wire. INSTALL a new stoplamp switch. REFER to Stoplamp Switch Service and Repair. TEST the system for normal operation.
No
REMOVE the jumper wire. REPAIR circuit CCB08 (VT/WH) for an open. TEST the system for normal operation.
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I3 CHECK CIRCUIT SBP02 (YE/RD) FOR AN OPEN
- Disconnect: SJB C2280d.
- Measure the resistance between the stoplamp switch C278-1, circuit SBP02 (YE/RD), harness side and the SJB C2280d-13, circuit SBP02 (YE/RD), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to I4.
No
REPAIR SBP02 (YE/RD) for an open. TEST the system for normal operation.
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I4 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 Multifunction Electronic Modules Service and Repair. 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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