Pinpoint Test T: Both Fog Lamps Are Inoperative
Fog Lamps
Pinpoint Tests
Pinpoint Test T: Both Fog Lamps Are Inoperative
Refer to Wiring Diagram Set 11, Fuse and Relay Information for schematic and connector information. Diagrams By Number
Refer to Wiring Diagram Set 86, Fog Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a voltage signal to the headlamp switch to monitor the fog lamp request. When the fog lamp switch is engaged, the voltage signal is routed to ground. When the SJB detects the fog lamps on request, the SJB energizes the fog lamp relay (integrated into the SJB).
When the fog lamp relay is energized on vehicles without the automatic high beam feature, voltage is routed to the fog lamps.
When the fog lamp relay is energized on vehicles with the automatic high beam feature, voltage is routed to the fog lamps deactivation relay (located in the Battery Junction Box (BJB)). When the high beams are not on, voltage passes through the relay to the fog lamps.
The fog lamps share a common ground.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Fog lamps deactivation relay (if equipped)
- Headlamp switch
- SJB
PINPOINT TEST T: BOTH 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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T1 CHECK THE SJB FOG LAMP SWITCH PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB fog lamp PID (FOG SW) while engaging the fog lamp switch.
- Does the PID indicate the fog lamp switch is on?
Yes
GO to T4.
No
GO to T2.
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T2 CHECK FOR VOLTAGE TO THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Ignition ON.
- Measure the voltage between the headlamp switch C205-6, circuit CLF18 (BU/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. TEST the system for normal operation.
No
GO to T3.
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T3 CHECK THE FOG LAMPS REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-6, circuit CLF18 (BU/WH), harness side and the SJB C2280b-49, circuit CLF18 (BU/WH), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to T9.
No
REPAIR circuit CLF18 (BU/WH) for an open. TEST the system for normal operation.
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T4 CHECK FOR VOLTAGE TO THE FOG LAMPS
- Ignition OFF.
- Disconnect: LH Fog Lamp C152.
- Ignition ON.
- Place the headlamp switch in the PARKING LAMPS ON position and engage the fog lamp switch.
- Measure the voltage between the LH fog lamp C152-A, circuit CLF12 (BN/YE), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
REPAIR circuit GD123 (BK/GY) for an open. TEST the system for normal operation.
No
For vehicles equipped with the automatic high beam feature, GO to T5.
For vehicles not equipped with the automatic high beam feature, VERIFY the SJB fuse 21 (15A) is OK. If OK, GO to T8. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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T5 CHECK FOR VOLTAGE TO THE FOG LAMPS DEACTIVATION RELAY
- Connect: LH Fog Lamp C152.
- Disconnect: Fog Lamps Deactivation Relay.
- Measure the voltage between the fog lamps deactivation relay pin 4, circuit CLF28 (BN/WH), BJB face side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to T7.
No
VERIFY the SJB fuse 21 (15A) is OK. If OK, GO to T6. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Diagrams By Number
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T6 CHECK THE FOG LAMPS SUPPLY CIRCUIT FOR AN OPEN TO THE FOG LAMPS DEACTIVATION RELAY
- Connect: Fog Lamps Deactivation Relay.
- Ignition OFF.
- Disconnect: SJB C2280e.
- Connect a fused jumper wire between the SJB C2280e-1, circuit CDC34 (WH/OG) (without Intelligent Access (IA)) or CBB36 (BU/BN) (with IA), harness side and the SJB C2280e-3, circuit CLF28 (BN/WH), harness side.
- Ignition ON.
- Do the fog lamps illuminate?
Yes
REMOVE the jumper wire. GO to T9.
No
REMOVE the jumper wire. REPAIR circuit CLF28 (BN/WH) for an open. TEST the system for normal operation.
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T7 BYPASS THE FOG LAMPS DEACTIVATION RELAY
- Ignition OFF.
- Connect a fused jumper wire between the fog lamps deactivation relay pin 4, circuit CLF28 (BN/WH), BJB face side and fog lamps deactivation relay pin 3, circuit CLF12 (BN/YE), BJB face side.
- Ignition ON.
- Do the fog lamps illuminate?
Yes
REMOVE the jumper wire. INSTALL a new fog lamps deactivation relay. TEST the system for normal operation.
No
REMOVE the jumper wire. REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.
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T8 CHECK THE FOG LAMPS VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Connect: LH Fog Lamp C152.
- Ignition OFF.
- Disconnect: SJB C2280e.
- Connect a fused jumper wire between the SJB C2280e-1, circuit CDC34 (WH/OG) (without Intelligent Access (IA)) or CBB36 (BU/BN) (with IA), harness side and the SJB C2280e-3, circuit CLF12 (BN/YE), harness side.
- Ignition ON.
- Do the fog lamps illuminate?
Yes
REMOVE the jumper wire. GO to T9.
No
REMOVE the jumper wire. REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.
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T9 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.
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