Ford Workshop Service and Repair Manuals > Maverick 2005 (08.2004-) > Mechanical Repairs | 4 Electrical | 417 Lighting | 417-01 Exterior Lighting | Description and Operation | Diagnosis and Testing

Exterior Lighting - Reversing Lamps

Maverick 2005 (08/2004-)

Diagnosis and Testing

Special Tool(s)

73III Automotive Meter

105-R0057 or equivalent

Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

Flex Probe Kit

105-R025C or equivalent

Principles of Operation

For vehicles equipped with an automatic transaxle, the smart junction box (SJB) receives transmission gear status from the instrument cluster over the communication network. When a message is sent over the communication network stating the transaxle is in REVERSE (R), the SJB energizes an internal relay which supplies voltage to the reversing lamps.

For vehicles equipped with a manual transaxle, the SJB sends a voltage reference signal to the reversing lamp switch. When the transaxle is placed in REVERSE (R), the reference signal is routed to ground. When the SJB detects the transaxle is in REVERSE (R), the SJB energizes an internal relay which supplies voltage to the reversing lamps.

The SJB utilizes a protective circuit strategy for many of its outputs (for example, the headlamp output circuit). Output loads (current level) are monitored for excessive current (typically short circuits) and are shut down (turns off the voltage or ground provided by the module) when a fault is detected. A continuous diagnostic trouble code (DTC) is stored at that time for the fault. The circuit will then reset after an ignition cycle or customer demand of the function (switching the component on, 30-minute battery saver being energized). When an excessive circuit load occurs several times, the module shuts down the output until a service procedure is performed. At the same time, the continuous DTC that was stored on the first failure will not clear by a command to clear the continuous DTCs. The module will not allow this code to be cleared or the circuit restored to normal until a successful on-demand self-test proves that the fault has been repaired. After the on-demand self-test has successfully completed (no on-demand DTCs present), the continuous DTC will have been cleared and the circuit function will return.

Inspection and Verification

Verify the customer concern.

Visually inspect the following for obvious signs of mechanical or electrical damage.

Visual Inspection Chart

Mechanical	Electrical
Reversing lamp switch (manual transaxle) Digital transmission range (TR) sensor (automatic transaxle)	Smart junction box (SJB) fuse 29 (10A) (reversing lamps) SJB Instrument cluster Bulb(s) Circuitry

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 the multifunction switch is in the OFF position.

NOTE:Make sure the multifunction switch is in the LOW BEAM position.

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 Module Communications Network, No Power To The Scan Tool, to diagnose no communication with 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 Module Communications Network to diagnose no response from the powertrain control module (PCM).

Carry out the network test:
- If the scan tool responds with no communication for one or more modules, refer to Section 418-00 Module Communications Network.
- 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 Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index. For all other DTCs, refer to Section 419-10 Multifunction Electronic Modules.

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

Smart Junction Box (SJB) Diagnostic Trouble Code (DTC) Index

DTC	Description	Action
B1342	ECU Is Faulted	CLEAR the DTCs. RETRIEVE the DTCs. If DTC B1342 is retrieved again, INSTALL a new SJB. REFER to Section 419-10 Multifunction Electronic Modules. TEST the system for normal operation.
B2382	Backup Light Relay Circuit- Open	VERIFY the SJB fuse 29 (10A) is OK. If OK, RUN the on-demand self-test. If DTC B2382 is retrieved again, INSTALL a new SJB. REFER to Section 419-10 Multifunction Electronic Modules. TEST the system for normal operation.
B2407	Backup Light Relay Circuit - High	RUN the on-demand self-test. If DTC B2407 is retrieved again, INSTALL a new SJB. REFER to Section 419-10 Multifunction Electronic Modules. TEST the system for normal operation.
P0812	Reverse Input Circuit	GO to Pinpoint Test x.
All other DTCs	—	REFER to Section 419-10 Multifunction Electronic Modules.

Symptom Chart

Symptom	Possible Sources	Action
The reversing lamps are inoperative	* Fuse * Circuitry * Reversing lamp switch * Smart junction box (SJB) * Instrument cluster	* GO to Pinpoint Test w.
The individual reversing lamp is inoperative	* Circuitry	* MEASURE the resistance between the LH reversing lamp C451-3, circuit 57 (BK), harness side and ground; or between the RH reversing lamp C461-3, circuit 57 (BK), harness side and ground. - If the resistance is less than 5 ohms, REPAIR circuit 140 (BK/PK). TEST the system for normal operation. - If the resistance is not less than 5 ohms, REPAIR circuit 57 (BK). TEST the system for normal operation.
The reversing lamps are on continuously	* Circuitry * Reversing lamp switch * SJB * Instrument cluster	* GO to Pinpoint Test x.

Pinpoint Tests

Pinpoint Test W: The Reversing Lamps Are Inoperative

Refer to Wiring Diagrams Cell 93, for schematic and connector information.

Normal Operation — Automatic Transaxle

When the vehicle is placed in REVERSE (R), the PCM sends a message over the high speed CAN to the instrument cluster indicating the transaxle is in reverse gear. The instrument cluster then sends a message over the medium speed CAN to the smart junction box (SJB) indicating the transaxle is in reverse gear. The SJB then provides ground to an internal relay which routes voltage to circuit 140 (BK/PK) to the reversing lamps. Ground is provided to the reversing lamps through circuit 57 (BK).

Normal Operation — Manual Transaxle

The SJB sends a reference signal to the reversing lamp switch through circuit 1789 (VT/WH). When the transaxle is placed in reverse gear, the reversing lamp switch routes the voltage signal to ground through circuit 57 (BK). When the transaxle is placed in reverse gear, the SJB provides ground to an internal relay which routes voltage through circuit 140 (BK/PK) to the reversing lamps. Ground is provided to the reversing lamps through circuit 57 (BK).

Possible Causes