Pinpoint Test P: The Fog Lamps Are Inoperative
Fog Lamps
Pinpoint Tests
Pinpoint Test P: The Fog Lamps Are Inoperative
Refer to Wiring Diagram Set 86, Fog Lamps for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 11, Fuse and Relay Information for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a voltage reference signal to the headlamp switch through circuit 1669 (OG/LG). When the fog lamp switch is engaged, the voltage signal is routed to ground. The fog lamp relay is provided voltage through the Bussed Electrical Center (BEC). When the ignition switch is in the ON position, the parking lamps are on and the SJB detects a request for the fog lamps, the SJB provides a ground for the fog lamp relay coil through circuit 1347 (DB/WH). When the relay is energized, voltage is routed through circuits 1721 (LB/BK) and 1776 (TN/OG) to the LH and RH fog lamps, respectively. The fog lamps share the ground circuit with the headlamps.
- DTC B2030 (Front Fog Lamp Relay Ckt Failure) - a continuous and on-demand DTC that sets when the SJB detects an open or short to voltage from the fog lamp relay coil ground controlled circuit.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Fog lamp relay
- Headlamp switch
- BEC
- SJB
PINPOINT TEST P: THE FOG LAMPS 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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P1 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Ignition OFF.
- Retrieve the recorded results from the SJB self-test.
- Is DTC B2030 present?
Yes
GO to P2.
No
GO to P8.
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P2 CHECK THE FOG LAMP RELAY (DTC B2030)
- Disconnect: Fog Lamp Relay.
- Substitute a known good relay and recheck the system.
- Do the fog lamps operate correctly?
Yes
REMOVE the known good relay. INSTALL a new fog lamp relay. CLEAR the DTCs. REPEAT the self-test.
No
REMOVE the known good relay. GO to P3.
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P3 CHECK VOLTAGE TO THE RELAY COIL
- Measure the voltage between the fog lamp relay pin 86, BEC face side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to P4.
No
VERIFY the BEC fuse 58 (15A) is OK. If OK, INSTALL a new BEC. CLEAR the DTCs. REPEAT the self-test. If not OK, REFER to the Wiring Diagrams to identify the possible cause of the circuit short.
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P4 CHECK THE FOG LAMP RELAY COIL GROUND CONTROL CIRCUIT FOR SHORT TO VOLTAGE
- Disconnect: SJB C2280c.
- Ignition ON.
- Measure the voltage between the fog lamp relay pin 85, circuit 1347 (DB/WH), BEC face side and ground.
- Is any voltage present?
Yes
GO to P5.
No
GO to P6.
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P5 CHECK CIRCUIT 1347 (DB/WH) FOR SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: BEC C1035a.
- Ignition ON.
- Measure the voltage between the fog lamp relay pin 85, circuit 1347 (DB/WH), BEC face side and ground.
- Is any voltage present?
Yes
INSTALL a new BEC. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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P6 CHECK THE FOG LAMP RELAY COIL GROUND CONTROL CIRCUIT FOR AN OPEN
- Ignition OFF.
- Measure the resistance between the fog lamp relay pin 85, circuit 1347 (DB/WH), BEC face side and the SJB C2280c-2, circuit 1347 (DB/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to P12.
No
GO to P7.
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P7 CHECK CIRCUIT 1347 (DB/WH) FOR AN OPEN
- Disconnect: BEC C1035a.
- Measure the resistance between the BEC C1035a-A3, circuit 1347 (DB/WH), harness side and the SJB C2280c-2, circuit 1347 (DB/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
INSTALL a new BEC. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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P8 CHECK THE FOG LAMP SWITCH INPUT
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB headlamp switch PID (FOG_SW) while placing the headlamp switch in the PARKING LAMPS ON position and engaging the fog lamp switch.
- Does the PID indicate the fog lamp switch is active?
Yes
GO to P11.
No
GO to P9.
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P9 CHECK THE HEADLAMP SWITCH
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Disconnect: Headlamp Switch C205.
- Carry out the headlamp switch component test.
- Is the headlamp switch OK?
Yes
GO to P10.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. TEST the system for normal operation.
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P10 CHECK CIRCUIT 1669 (OG/LG) FOR AN OPEN
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-6, circuit 1669 (OG/LG), harness side and the SJB C2280b-34, circuit 1669 (OG/LG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to P12.
No
REPAIR the circuit. TEST the system for normal operation.
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P11 CHECK THE FOG LAMP RELAY (NO DTCs)
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Substitute a known good relay and recheck the system.
- Do the fog lamps operate correctly?
Yes
REMOVE the known good relay. INSTALL a new fog lamp relay. TEST the system for normal operation.
No
REMOVE the known good relay. INSTALL a new BEC. TEST the system for normal operation.
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P12 CHECK FOR CORRECT SJB OPERATION
- Ignition OFF.
- 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. CLEAR the DTCs. REPEAT the self-test.
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