Pinpoint Test S: The Fog Lamps Are On Continuously
Fog Lamps
Pinpoint Tests
Pinpoint Test S: The Fog Lamps Are On Continuously
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. When the fog lamp switch is engaged, the voltage signal is routed to ground.
When the SJB detects the fog lamp on request, the SJB provides a voltage to the fog lamp relay coil. When the fog lamp relay is energized, voltage is sent to the fog lamps and on a separate circuit to the fog lamps on indicator.
- DTC B2254 (Front Fog Lamp Switch Failure) - an on-demand DTC that sets when the SJB detects a short to ground from the fog lamps on input circuit.
- DTC B2512 (Front Fog Lamp Relay Ckt Short to Battery) - a continuous and on-demand DTC that sets when the SJB detects a short to voltage from the fog lamp relay coil voltage supply circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Fog lamp relay
- Headlamp switch
- SJB
PINPOINT TEST S: THE FOG LAMPS ARE ON CONTINUOUSLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
-------------------------------------------------
S1 CHECK THE HEADLAMP SWITCH PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- NOTE: Make sure the headlamp switch is in the OFF position.
- Monitor the SJB headlamp switch PID (FOG SW).
- Does the PID agree with the headlamp switch position?
Yes
GO to S4.
No
GO to S2.
-------------------------------------------------
S2 CHECK THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Ignition ON.
- Do the fog lamps continue to illuminate?
Yes
GO to S3.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
S3 CHECK THE FOG LAMP REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280d.
- Measure the resistance between the headlamp switch C205-6, circuit CLF21 (GY/VT), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to S9.
No
REPAIR circuit CLF21 (GY/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
S4 CHECK THE FOG LAMP RELAY OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Disconnect: Fog Lamp Relay.
- Do the fog lamps continue to illuminate?
Yes
REPAIR circuit CLF12 (BN/YE) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to S5.
-------------------------------------------------
S5 CHECK THE FOG LAMP RELAY
- Substitute a known good relay.
- Do the fog lamps continue to illuminate?
Yes
REMOVE the known good relay. INSTALL the original fog lamp relay. GO to S6.
No
REMOVE the known good relay. INSTALL a new fog lamp relay. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
S6 CHECK THE HEADLAMP SWITCH FOR A SHORT TO VOLTAGE
- Disconnect: Headlamp Switch C205.
- Do the fog lamps continue to illuminate?
Yes
GO to S7.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
S7 CHECK THE SJB FOG LAMP RELAY COIL OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (TO HEADLAMP SWITCH)
- Disconnect: SJB C2280d.
- Do the fog lamps continue to illuminate?
Yes
REPAIR circuit CLF28 (BN/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to S8.
-------------------------------------------------
S8 CHECK THE SJB FOG LAMP RELAY COIL OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (TO FOG LAMP RELAY)
- Disconnect: SJB C2280e.
- Do the fog lamps continue to illuminate?
Yes
REPAIR circuit CLF28 (BN/WH) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to S9.
-------------------------------------------------
S9 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 any DTCs. REPEAT the self-test.
-------------------------------------------------