2014 Mustang Workshop Manual

SECTION 417-01: Exterior Lighting	2014 Mustang Workshop Manual
DIAGNOSIS AND TESTING	Procedure revision date: 01/07/2013

Fog Lamps

Special Tool(s)
	Fluke 77-IV Digital Multimeter FLU77-4 or equivalent
	Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool
	Flex Probe Kit 105-R025D or equivalent

Principles of Operation

NOTE: The Smart Junction Box (SJB) is also known as the Generic Electronic Module (GEM).

The SJB monitors the headlamp switch position by sending a voltage signal to the headlamp switch. When the fog lamp switch (part of the headlamp switch) is engaged, the voltage reference signal is routed to ground.

The fog lamps can be turned on when the following conditions are met:

The ignition switch is in the RUN or START position
The low beam headlamps or the parking lamps are on
The high beams are off

When the SJB receives an input from the headlamp switch indicating a request for the fog lamps, the SJB energizes the fog lamp relay (integrated into the SJB ). When the fog lamp relay is energized, voltage is routed to the fog lamps and the fog lamps on indicator (located within the headlamp switch). The GT fog lamps are equipped with an LED that is only serviced with the fog lamp assembly.

Inspection and Verification

Verify the customer concern.

Visually inspect for obvious signs of electrical damage.

Visual Inspection Chart

Electrical
Smart Junction Box (SJB) fuse 21 (15A) Bulb (except GT) Fog lamp assembly (GT only) Wiring, terminals or connectors Headlamp switch SJB

If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

NOTE: Make sure to use the latest scan tool software release.
If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).

NOTE: The Vehicle Communication Module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM .
If the scan tool does not communicate with the VCM :
- Check the VCM connection to the vehicle.
- Check the scan tool connection to the VCM .
- Refer to Section 418-00 , No Power To The Scan Tool, to diagnose no power to the scan tool.

If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.
- Verify the scan tool operation with a known good vehicle.
- Refer to Section 418-00 to diagnose no response from the PCM.

Carry out the network test.
- If the scan tool responds with no communication for one or more modules, refer to Section 418-00 .
- If the network test passes, retrieve and record the continuous memory DTCs.

Clear the continuous DTCs and carry out the self-test diagnostics for the SJB .

If the DTCs retrieved are related to the concern, go to the Diagnostic Trouble Code (DTC) Chart in this section. For all other DTCs, refer to the Diagnostic Trouble Code (DTC) Chart in Section 419-10 .

If no DTCs related to the concern are retrieved, GO to Symptom Chart .

Symptom Chart

Symptom Chart
Condition	Possible Sources	Action
Both fog lamps are inoperative	Fuse Wiring, terminals or connectors Headlamp switch Smart Junction Box (SJB)	GO to Pinpoint Test S .
An individual fog lamp is inoperative	Wiring, terminals or connectors	All except GT, VERIFY the bulb is OK. If OK, GO to Pinpoint Test T . For GT, GO to Pinpoint Test T .
The fog lamps are on continuously	Wiring, terminals or connectors Headlamp switch SJB	GO to Pinpoint Test U .
The fog lamps on indicator is inoperative	Wiring, terminals or connectors Headlamp switch SJB	GO to Pinpoint Test V .

Pinpoint Tests

Pinpoint Test S: Both Fog Lamps Are Inoperative

Refer to Wiring Diagrams Cell 86 , Fog Lamps for schematic and connector information.

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, voltage is routed to the fog lamps.

This pinpoint test is intended to diagnose the following:

Fuse
Wiring, terminals or connectors
Headlamp switch
SJB

PINPOINT TEST S: 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.

Test Step	Result / Action to Take
S1 CHECK THE SJB FOG LAMP SWITCH PID
Ignition ON. Enter the following diagnostic mode on the scan tool: SJB Data Logger. 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 VERIFY the SJB fuse 21 (15A) is OK. If OK, GO to S4 . If not OK, REFER to the Wiring Diagrams Manual to identify the possible causes of the circuit short. No GO to S2 .
S2 CHECK FOR VOLTAGE TO THE HEADLAMP SWITCH
Ignition OFF. Disconnect: Headlamp Switch C205. Ignition ON. Measure the voltage between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and ground. Is the voltage greater than 11 volts?	Yes INSTALL a new headlamp switch. REFER to Headlamp Switch in this section. TEST the system for normal operation. No GO to S3 .
S3 CHECK THE FOG LAMPS ON REQUEST INPUT CIRCUIT FOR AN OPEN
Disconnect: SJB C2280b. Measure the resistance between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and the SJB C2280b-49, circuit CLF21 (GY/VT), harness side. Is the resistance less than 3 ohms?	Yes GO to S5 . No REPAIR circuit CLF21 (GY/VT) for an open. TEST the system for normal operation.
S4 BYPASS THE SJB
Ignition OFF. Disconnect: SJB C2280e. Connect a fused jumper wire between the SJB C2280e-1, circuit CE612 (GY/VT), 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 S6 . No LEAVE the jumper wire connected. GO to S5 .
S5 CHECK FOR VOLTAGE TO THE FOG LAMP
Ignition OFF. Disconnect: Inoperative Fog Lamp. Ignition ON. Place the headlamp switch in the PARKING LAMPS ON position and engage the fog lamp switch. For vehicles with 3.7L engines or the California Special package, measure the voltage between the LH fog lamp C1578-A, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1579-A, circuit CLF12 (BN/YE), harness side and ground. For vehicles with 5.0L engines without the California Special package, measure the voltage between the LH fog lamp C152-4, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C162-4, circuit CLF12 (BN/YE), harness side and ground. For vehicles with 5.8L engines, measure the voltage between the LH fog lamp C1322-A, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1323-A, circuit CLF12 (BN/YE), harness side and ground. Is the voltage greater than 11 volts?	Yes REPAIR the ground circuit in question for an open. TEST the system for normal operation. No REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.
S6 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 Section 419-10 . 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.

Pinpoint Test T: An Individual Fog Lamp Is Inoperative

Refer to Wiring Diagrams Cell 86 , Fog Lamps for schematic and connector information.

Normal Operation

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors

PINPOINT TEST T: AN INDIVIDUAL FOG LAMP IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Test Step	Result / Action to Take
T1 CHECK FOR VOLTAGE TO THE FOG LAMP
Ignition OFF. Disconnect: Inoperative Fog Lamp. Ignition ON. Place the headlamp switch in the PARKING LAMPS ON position and engage the fog lamp switch. For vehicles with 3.7L engines or the California Special package, measure the voltage between the LH fog lamp C1578-A, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1579-A, circuit CLF12 (BN/YE), harness side and ground. For vehicles with 5.0L engines without the California Special package, measure the voltage between the LH fog lamp C152-4, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C162-4, circuit CLF12 (BN/YE), harness side and ground. For vehicles with 5.8L engines, measure the voltage between the LH fog lamp C1322-A, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1323-A, circuit CLF12 (BN/YE), harness side and ground. Is the voltage greater than 11 volts?	Yes For all except GT, REPAIR the ground circuit in question for an open. TEST the system for normal operation. For GT, GO to T2 . No REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.
T2 CHECK THE FOG LAMP GROUND CIRCUIT
Measure the resistance between the LH fog lamp C152-2, circuit GD129 (BK/YE), harness side and ground; or between the RH fog lamp C162-2, circuit GD129 (BK/YE), harness side and ground. Is the resistance less than 5 ohms?	Yes INSTALL a new fog lamp assembly. Fog Lamp . No REPAIR the ground circuit in question for an open. TEST the system for normal operation.

Pinpoint Test U: The Fog Lamps Are On Continuously

Refer to Wiring Diagrams Cell 86 , Fog Lamps for schematic and connector information.

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, voltage is routed to the fog lamps, and on a separate output, to the headlamp switch for 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 on the fog lamps on input circuit.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Headlamp switch
SJB

PINPOINT TEST U: 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.

Test Step	Result / Action to Take
U1 CHECK FOR RECORDED SJB DTCs
Check the recorded results from the SJB self-test. Is DTC B2254 present?	Yes GO to U2 . No GO to U4 .
U2 CHECK THE HEADLAMP SWITCH
Ignition OFF. Disconnect: Headlamp Switch C205. Ignition ON. Do the fog lamps continue to illuminate?	Yes GO to U3 . No INSTALL a new headlamp switch. REFER to Headlamp Switch in this section. TEST the system for normal operation.
U3 CHECK THE FOG LAMPS ON REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
Disconnect: SJB C2280b. Measure the resistance between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and ground. Is the resistance greater than 10,000 ohms?	Yes GO to U6 . No REPAIR circuit CLF21 (GY/VT) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
U4 CHECK THE SJB FOG LAMPS OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (TO HEADLAMP SWITCH)
Ignition OFF. Disconnect: SJB C2280a. Ignition ON. Do the fog lamps continue to illuminate?	Yes GO to U5 . No REPAIR circuit CLF12 (BN/YE) for a short to voltage. TEST the system for normal operation.
U5 CHECK THE SJB FOG LAMPS OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE (TO THE FOG LAMPS)
Ignition OFF. Disconnect: SJB C2280e. Ignition ON. Do the fog lamps continue to illuminate?	Yes REPAIR circuit CLF12 (BN/YE) for a short to voltage. TEST the system for normal operation. No GO to U6 .
U6 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 . REFER to Section 419-10 . 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.

Pinpoint Test V: The Fog Lamps On Indicator Is Inoperative

Refer to Wiring Diagrams Cell 86 , Fog Lamps for schematic and connector information.

Normal Operation

When the Smart Junction Box (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, voltage is routed to the fog lamps, and on a separate output, to the headlamp switch for the fog lamps on indicator.

This pinpoint test is intended to diagnose the following:

Wiring, terminals or connectors
Headlamp switch
SJB

PINPOINT TEST V: THE FOG LAMPS ON INDICATOR IS INOPERATIVE

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

Test Step	Result / Action to Take
V1 CHECK THE HEADLAMP SWITCH
Ignition OFF. Disconnect: Headlamp Switch C205. Ignition ON. Enter the following diagnostic mode on the scan tool: SJB DataLogger. Select the SJB fog lamps (FOG_LMP) active command. Command the fog lamps on. NOTE: Make sure the fog lamps are illuminated when taking a reading. Measure the voltage between the headlamp switch C205-10, circuit CLF12 (BN/YE), harness side and ground. Is the voltage greater than 11 volts?	Yes INSTALL a new headlamp switch. REFER to Headlamp Switch in this section. TEST the system for normal operation. No GO to V2 .
V2 CHECK THE SJB FOG LAMPS OUTPUT CIRCUIT FOR AN OPEN
Ignition OFF. Disconnect: SJB C2280a. Measure the resistance between the headlamp switch C205-10, circuit CLF12 (BN/YE), harness side and the SJB C2280a-6, circuit CLF12 (BN/YE), harness side. Is the resistance less than 3 ohms?	Yes GO to V3 . No REPAIR circuit CLF12 (BN/YE) for an open. CLEAR the DTCs. REPEAT the self-test.
V3 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 Section 419-10 . 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.