Diagnostics and testing of rear view mirrors (Discovery 3)

Review

The mirror operation is controlled by three different modules. These are the automatic temperature control module, the body control module and the seat memory module.

The heated mirror is controlled by the automatic temperature control module, so some diagnostic trouble codes (DTCs) are the same as the climate control system codes.

Information about mirrors and their operation can be found in the relevant section of the service station manual.

Inspection and verification

1. Ensure that the customer's complaint is justified.

2. Visually inspect for obvious mechanical and electrical problems.

Mechanical factors

Electrical factors

Condition and installation of the outside mirror switch Condition and installation of exterior mirrors

Battery status and charging Fuses Battery electrical junction box (BJB) - 12E fuse Battery electrical junction box (BJB) - 16E fuse Central electrical junction box (CJB) - 5P fuse Central electrical junction box (CJB) - fuse 16P Central electrical junction box (CJB) - fuse 33P Central electrical junction box (CJB) - fuse 46P Central electrical junction box (CJB) - fuse 69P Wiring harnesses and electrical connectors Washer nozzle and mirror heating element relay Memory function control module(s) Exterior mirror switch(es) Electric motor(s) for outside mirrors Ignition switch Battery Junction Box (BJB) Central Junction Box (CJB) Automatic temperature control module LIN electrical circuit (Local interconnect network)

3. If an obvious cause for the problem you identified or the customer described is found, resolve it before proceeding with further actions. (if possible).



4. Use the approved diagnostic system or scan tool to retrieve all diagnostic trouble codes (DTCs) before referring to the Symptom Chart and DTC Index.

Since DTCs are stored in more than one module, a full vehicle data read is recommended.

Clear all DTCs after troubleshooting.

Sign of malfunction	Possible reasons	Actions
Ice is not removed from the glass/washer nozzles freeze	Fuse failure Washer nozzle and mirror heating element relay malfunction Electrical circuit fault: high resistance Electrical circuit fault: short circuit to ground Automatic temperature control module failure	Check the fuses. Check the operation of the relay for heating the washer nozzles and mirrors. (see visual inspection table). Check the electrical circuits for the heated washer nozzles and mirrors. Refer to the electrical manual. If the module is suspected, refer to the warranty policy and procedures manual.
Mirrors do not rotate in one or more directions	Mechanical failure Switch malfunction Electric motor failure Electrical circuit fault: high resistance Electrical circuit fault: short circuit to ground	Press the mirror switch and listen for the sound of the motor(s). If you hear the sound of the motor(s), check the mirror mechanical components and linkages. Repair if necessary. Check for DTCs that indicate a faulty switch, motor, or circuit.
The stored mirror position is not restored.	Battery voltage is less than 10.5V The position is not stored in memory The switch is pressed during operation of the "one-touch" memorized position recovery function. EEPROM failure	Before assuming a faulty memory element, check the operation of the switch and refer to the symptoms described above. Make sure there is sufficient battery voltage. Make sure the desired position is correctly stored in memory. Make sure the procedure for storing/restoring the stored position is carried out correctly. Refer to the relevant section in the workshop manual.
The function does not work "Lazy entry"	Remote transmitter malfunction (power supply, transmitter programming, etc.) See the list in the section "The stored position is not restored".	Check if the remote transmitter controls the central locking etc. If yes, the fault is not in the transmitter. Refer to the section "Memorised position is not restored"

DTC Index

NOTE: Generic scan tools cannot read the codes listed or can only read 5-digit codes. Match the 5 digits from the scan tool with the first 5 digits of the listed 7-digit code to identify the fault. (the last 2 digits provide additional information readable by a manufacturer approved diagnostic system).

NOTE: For a complete listing of climate control system DTCs, refer to Section 412-00, Climate Control System, in the service manual.

DTC codes	Description	Possible reasons	Actions
B1B8541	Memory module	Error in seat module	Replace the seat memory module If you have any doubts about the module's functionality, refer to the warranty policy and procedures manual.
B1B8549	Memory module	Error in seat module	If there is no customer complaint about seat operation, no action is required, clear/ignore DTC. If seat operation is affected, replace module. If in doubt about module functionality, refer to Warranty Policy and Procedures Manual.
B1B8587	Memory module	Seat memory module does not respond	The seat settings memory module is not installed on all modifications (custom installation). Registration of the failure is prohibited by the CCF file, but if the CCF file is incorrectly configured, it is possible for the DTC to be registered by mistake. Repair is required only for vehicles with a sunroof. If necessary, see the description of the "Lost Communication" condition at the beginning of this table.
B1C0273	Position memory function switch	Position Memory Function Switch: Stuck Position memory function switch: short circuit to ground	Refer to the electrical manuals and check the wiring between the seat memory module and the switch cluster for a short to ground. Check the switch operation and replace if necessary.
B1C0373	Memory Cell Switch #1	Memory Cell Switch #1: Stuck Memory Cell Switch #1: Short to Ground	Refer to the electrical manuals and check the wiring between the seat memory module and the switch cluster for a short to ground. Check the switch operation and replace if necessary.
B1C0473	Memory Cell Switch #2	Memory Cell Switch #2: Stuck Memory Cell Switch #2: Short to Ground	Refer to the electrical manuals and check the wiring between the seat memory module and the switch cluster for a short to ground. Check the switch operation and replace if necessary.
B1C0573	Memory Cell Switch #3	Memory Cell Switch #3: Stuck Memory Cell Switch #3: Short to Ground	Refer to the electrical manuals and check the wiring between the seat memory module and the switch cluster for a short to ground. Check the switch operation and replace if necessary.
B1C0601	Electrical circuit of the driver's mirror up/down motor and general mirror control	Open or short circuit in the mirror up/down motor circuit Mirror up/down motor failure	Refer to the electrical manuals and check the wiring between the seat memory module and the door mirror for an open circuit or short to ground. Check the operation of the mirror and replace it if necessary.
B1C0701	Electrical circuit of the electric motors for turning left/right of the driver's mirror and raising/lowering of the right mirror	Open or short circuit in the left/right mirror rotation motor circuit Left/right mirror rotation motor failure	Refer to the electrical manuals and check the wiring between the seat memory module and the door mirror for an open circuit or short to ground. Check the operation of the mirror and replace it if necessary.
B1C0801	Electric circuit of the left/right turn motor of the passenger mirror and the general control of the mirrors	Open or short circuit in the left/right mirror rotation motor circuit Left/right mirror rotation motor failure	Refer to the electrical manuals and check the wiring between the seat memory module and the door mirror for an open circuit or short to ground. Check the operation of the mirror and replace it if necessary.
B1C0973	Driver's left/right mirror turn motor electrical circuit	Software error (dTC registration is possible when turning the mirror manually) Open or short circuit in the left/right mirror rotation motor circuit Left/right mirror rotation motor failure	If there is no customer complaint about the mirror operation, no action is required, clear/ignore the DTC. If the mirror operation is not normal, refer to the electrical diagrams and check the circuit for a short to ground or an open circuit. Replace the mirror/motor if necessary.
B1C1073	Driver's mirror up/down motor electrical circuit	Software error (dTC registration is possible when turning the mirror manually) Open or short circuit in the mirror up/down motor circuit Mirror up/down motor failure	If there is no customer complaint about the mirror operation, no action is required, clear/ignore the DTC. If the mirror operation is not normal, refer to the electrical diagrams and check the circuit for a short to ground or an open circuit. Replace the mirror/motor if necessary.
B1C1173	Passenger Mirror Left/Right Turn Motor Electrical Circuit	Software error (dTC registration is possible when turning the mirror manually) Open or short circuit in the left/right mirror rotation motor circuit Left/right mirror rotation motor failure	If there is no customer complaint about the mirror operation, no action is required, clear/ignore the DTC. If the mirror operation is not normal, refer to the electrical diagrams and check the circuit for a short to ground or an open circuit. Replace the mirror/motor if necessary.
B1C1273	Passenger mirror up/down motor electrical circuit	Software error (dTC registration is possible when turning the mirror manually) Open or short circuit in the mirror up/down motor circuit Mirror up/down motor failure	If there is no customer complaint about the mirror operation, no action is required, clear/ignore the DTC. If the mirror operation is not normal, refer to the electrical diagrams and check the circuit for a short to ground or an open circuit. Replace the mirror/motor if necessary.
B1C133A	Driver's mirror up/down motor feedback circuit	Electric motor of the door mirror has moved beyond the expected range Break or short circuit of the electrical circuit of the sensor Malfunction of the sensor of the position of the electric motor of the door mirror	Refer to electrical manuals and check the wiring harness and connectors between the seat memory module and the mirror. Repair/replace as necessary. Check/replace the mirror motor/entire assembly.
B1C143A	Driver's Mirror Left/Right Turn Motor Feedback Circuit	Electric motor of the door mirror has moved beyond the expected range Break or short circuit of the electrical circuit of the sensor Malfunction of the sensor of the position of the electric motor of the door mirror	Refer to electrical manuals and check the wiring harness and connectors between the seat memory module and the mirror. Repair/replace as necessary. Check/replace the mirror motor/entire assembly.
B1C153A	Passenger mirror up/down motor feedback circuit	Electric motor of the door mirror has moved beyond the expected range Break or short circuit of the electrical circuit of the sensor Malfunction of the sensor of the position of the electric motor of the door mirror	Refer to electrical manuals and check the wiring harness and connectors between the seat memory module and the mirror. Repair/replace as necessary. Check/replace the mirror motor/entire assembly.
B1C163A	Passenger Mirror Left/Right Turn Motor Feedback Circuit	Electric motor of the door mirror has moved beyond the expected range Break or short circuit of the electrical circuit of the sensor Malfunction of the sensor of the position of the electric motor of the door mirror	Refer to electrical manuals and check the wiring harness and connectors between the seat memory module and the mirror. Repair/replace as necessary. Check/replace the mirror motor/entire assembly.
B1C1773	Driver's left mirror switch	Left Mirror Switch: Sticking Left Mirror Switch: Short to Ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C1873	Driver's right mirror switch	Right Mirror Switch: Sticking Right Mirror Switch: Short to Ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C1973	Driver's mirror lift switch	Mirror up switch: sticking Mirror up switch: short circuit to ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C2073	Driver's mirror down switch	Mirror down switch: sticking Mirror down switch: short to ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C2173	Left Passenger Mirror Switch	Left Mirror Switch: Sticking Left Mirror Switch: Short to Ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C2273	Right Passenger Mirror Switch	Right Mirror Switch: Sticking Right Mirror Switch: Short to Ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C2373	Passenger Mirror Up Switch	Mirror up switch: sticking Mirror up switch: short circuit to ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.
B1C2473	Passenger mirror down switch	Mirror down switch: sticking Mirror down switch: short to ground	Refer to the electrical manuals and check the wiring between the memory module and the mirror switch assembly for a short to ground. Check the switch operation and replace if necessary.