Rear View Mirror: Overview Ford Expedition III

Principles of Operation

The movement of the LH and RH exterior mirror glass is controlled by the exterior mirror control switch and the LH and RH exterior mirror motors. Adjusting the exterior mirror switch to the LH or RH position determines which exterior mirror motor will be controlled.

If equipped with power folding mirrors, the center position of the exterior mirror control switch controls the power folding mirrors.

The exterior mirrors use a jumper harness between the vehicle wire harness connector and the exterior mirror motor. The exterior mirror jumper harness is integral to the exterior mirror. Before replacing an exterior mirror or mirror motor, inspect the jumper harness for open and shorted circuits or damaged and pushed-out pins. If a concern with the exterior mirror jumper harness exists, an attempt to repair the jumper harness should be made.

Only vehicles equipped with memory exterior mirrors are capable of setting DTCs.

Normal Operation

The exterior mirror control switch receives voltage from Smart Junction Box (SJB) fuse 12 (7.5A) through circuit SBP12 (GN/RD) and ground through circuit GD143 (BK/VT). The exterior mirror control switch uses circuit CPM23 (GY) as the common circuit for exterior mirror motor up/down and right/left movement.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Exterior mirror control switch

Under normal operation, the exterior mirror control switch uses circuit CPM23 (GY) as the common circuit for both exterior mirror motor up/down and right/left movement.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Exterior mirror control switch
3. Exterior mirror motor
4. Exterior mirror

Under normal operation, the exterior mirror control switch uses circuits CPM16 (BN/BU), CPM17 (BU/GN), CPM20 (BN/WH), CPM21 (YE/VT) or CPM23 (GY) to control the exterior mirror movement. The exterior mirror switch controls the LH exterior mirror motor movement by switching voltage and ground to circuits CPM16 (BN/BU), CPM17 (BU/GN) and CPM23 (GY). The exterior mirror switch controls the RH exterior mirror motor movement by switching voltage and ground to circuits CPM20 (BN/WH), CPM21 (YE/VT) and CPM23 (GY).

Mirror Movement

1. When the LH/RH exterior mirror motor receives voltage through circuit CPM16 (BN/BU)/CPM20 (BN/WH) and ground through circuit CPM23 (GY), the LH/RH exterior mirror will operate rightward.
2. When the LH/RH exterior mirror motor receives ground through circuit CPM16 (BN/BU)/CPM20 (BN/WH) and voltage through circuit CPM23 (GY), the LH/RH exterior mirror will operate leftward.
3. When the LH/RH exterior mirror motor receives voltage through circuit CPM17 (BU/GN)/CPM21 (YE/VT) and ground through circuit CPM23 (GY), the LH/RH exterior mirror will operate upward.
4. When the LH/RH exterior mirror motor receives ground through circuit CPM17 (BU/GN)/CPM21 (YE/VT) and voltage through circuit CPM23 (GY), the LH/RH exterior mirror will operate downward.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Exterior mirror control switch
3. Exterior mirror motor
4. Exterior mirror

Under normal operation, the exterior mirror control switch receives voltage from Smart Junction Box (SJB) fuse 12 (7.5A) through circuit SBP12 (GN/RD) and ground from circuit GD133 (BK). The exterior mirror control switch sends input to the Driver Seat Module (DSM) for the LH exterior mirror by switching voltage and ground to circuits CPM14 (GY/BN), CPM15 (VT/OG) and CPM23 (GY) and for the RH exterior mirror by switching voltage and ground to circuits CPM18 (GN/BN), CPM19 (GY/OG) and CPM23 (GY). The DSM will provide the appropriate voltage and ground signals for the LH exterior mirror motor up/down circuits CPM26 (WH), CPM29 (GN) and left/right circuits CPM26 (WH), CPM28 (BU/BN) or the RH exterior mirror motor up/down circuits CPM31 (YE/GY), CPM34 (WH/BN) and left/right circuits CPM31 (YE/GY), CPM33 (WH/VT).

The DSM supplies the LH and RH exterior mirror feedback potentiometer reference voltage through circuit LPM30 (GY/VT) and ground through circuit RPM30 (YE). The DSM receives feedback from the LH exterior mirror feedback potentiometer through circuit (left/right) VPM35 (YE/BU) and circuit (up/down) VPM36 (BN/YE). The DSM receives feedback from the RH exterior mirror feedback potentiometer through circuit (left/right) VPM37 (BU/OG) and circuit (up/down) VPM38 (BN/GN).

DTC DESCRIPTION

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Exterior mirror control switch
4. Exterior mirror motor
5. Exterior mirror
6. DSM

When the exterior mirror control switch is set to the center position and pressed rearward to the FOLD/UNFOLD position, ground is supplied to the Driver Seat Module (DSM) through circuit CPM22 (GY/BN). The power folding mirrors will operate in the opposite direction of the last activation. When the exterior mirrors are extended or retracted, and the DSM receives ground on circuit CPM22 (GY/BN), the DSM will ground circuit CPM39 (GN/VT) and supply voltage to circuit CPM04 (VT/BN), and the LH and RH exterior mirrors will either extend or retract.

If the power folding mirrors are folded or unfolded continuously (6 to 10 cycles), the power lockout feature will disable the system for approximately 7-10 minutes to prevent damage to the power fold motors. After 7-10 minutes have elapsed, normal operation will resume.

1. DTC B112B (Mirror Power Fold Switch Input Short to Battery) - Short to battery on mirror power fold switch input circuit.

This pinpoint test is intended to diagnose the following

1. Wiring, terminals or connectors
2. Exterior mirror control switch
3. Exterior mirror
4. DSM

Under normal operation, when the rear window defrost switch is pressed to the ON position, the rear window defrost relay closes and voltage is supplied to circuit CRD06 (BN/YE) to Battery Junction Box (BJB) fuse 59 (15A). The heated exterior mirrors receive voltage through circuit CBB59 (BN/WH) from BJB fuse 59 (15A). Ground is supplied to the LH heated exterior mirror through circuit GD143 (BK/VT) and to the RH heated exterior mirror through circuit GD138 (BK/WH).

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Exterior mirror glass
4. Exterior mirror

Under normal operation, the interior auto-dimming mirror receives voltage from Smart Junction Box (SJB) fuse 41 (15A) through circuit CBP41 (BU) and ground from circuit GD133 (BK). When the selector lever is placed in REVERSE, voltage is sent to circuit CLS10 (GN/BN) and the interior auto-dimming mirror will turn the dimming feature off. There are 2 photoelectric sensors: one in the front of the interior rear view mirror and one mounted on the glass side of the mirror. If the sensors are blocked, the interior auto-dimming feature might not work correctly. Always verify both sensors are not physically blocked before attempting to diagnose interior auto-dimming mirror concerns.

This pinpoint test is intended to diagnose the following

1. Fuse
2. Wiring, terminals or connectors
3. Interior auto-dimming mirror