For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC B154A 39: Driver Mirror Internal Malfunction
DTC B154B 39: Passenger Mirror Internal Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Position Sensor 5 V Reference | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Left/Right Mirror Horizontal Position Sensor Signal | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Left/Right Mirror Vertical Position Sensor Signal | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Left/Right Mirror Motor Horizontal Control | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Left/Right Mirror Motor Common Control | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Left/Right Mirror Motor Vertical Control | B154A 39, B154B 39 | B154A 39, B154B 39 | B154A 39, B154B 39 | --
Low Reference | -- | B154A 39, B154B 39 | -- | --

### Circuit/System Description

The outside mirror switch and passenger window switch are on a serial data circuit with the memory seat module as the master. The mirror select and directional control switches are inputs to the memory seat module through the serial data circuit. When the memory seat module receives switch inputs from the outside mirror switch, mirror output commands are sent to the appropriate switch through the serial data circuit. The outside mirror switch and passenger window switch control the left and right outside rear view mirrors through bi-directional motor control circuits. The motor control circuits are floating while in an inactive state and the switches will apply power and ground to the control circuits as necessary to move the mirror in the commanded direction.

Mirror position is determined by both horizontal and vertical position sensors in each of the power mirrors. The outside mirror switch and passenger window switch supply a 5 V reference, low reference, and horizontal and vertical position signal circuits to these sensors. The signal circuits are referenced from 5 V by the switches and the signal circuit voltage levels represent the mirror positions. The mirror positions are sent to the memory seat module through the serial data circuit where they are stored for memory mirror operation. When the memory seat module receives a memory recall command, the memory seat module will send the go to position commands to the outside mirror switch and passenger window switch. The switches will then drive the appropriate mirror motors to the commanded position sensor settings.

### Conditions for Running the DTC

Battery voltage must be between 9-16 V.

### Conditions for Setting the DTC

#### B154A 39

The outside mirror switch has determined a fault is present in a motor control circuit or a position sensor circuit.

#### B154B 39

The passenger window switch has determined a fault is present in a motor control circuit or a position sensor circuit.

### Action Taken When the DTC Sets

Memory mirror recall functions are suspended as long as the fault is present.

### Conditions for Clearing the DTC

• | A current DTC will clear when the fault is no longer present.

• | A history DTC will clear after 40 fault free ignition cycles.

### Reference Information

#### Schematic Reference

Outside Rearview Mirror Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Outside Mirror Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, observe the scan tool Mirror Select Switch parameter while cycling the mirror select switch between the left and right positions. The parameter should change between None, Right, and Left.

⇒ | If the parameter does not cycle between the specified values, replace the S52 outside mirror switch.

2. Observe the scan tool Mirror Direction Switch parameter while cycling the mirror directional switch between the up, down, left and right positions. The parameter should change between Idle, Up, Down, Left, and Right.

⇒ | If the parameter does not cycle between the specified values, replace the S52 outside mirror switch.

3. Command the driver and passenger mirrors UP/DOWN and RIGHT/LEFT with a scan tool. Verify the mirrors move in the commanded directions.

⇒ | If a mirror does not move in all the commanded directions refer to, Mirror Motor Circuit Test.

4. Operate the memory 1, 2, and 3 recall switches. The outside rearview mirrors should adjust to the stored memory positions.

⇒ | If a mirror does not adjust to the stored memory position refer to, Mirror Position Sensor Circuit Test.

### Circuit/System Testing

#### Mirror Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate A9 outside rearview mirror.
2. Connect a test lamp between the control circuit terminal 7 and the control circuit terminal 8.
3. Ignition ON, command the mirror LEFT and RIGHT with a scan tool. The test lamp should turn ON when commanding the LEFT and RIGHT states.

⇒ | If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground or an open/high resistance on either control circuit. If the circuits test normal, replace the appropriate switch.

• | S52 outside mirror switch

• | S79P passenger window switch

4. Connect a test lamp between the control circuit terminal 2 and the control circuit terminal 8.
5. Ignition ON, command the mirror UP and DOWN with a scan tool. The test lamp should turn ON when commanding the UP and DOWN states.

⇒ | If the test lamp remains OFF during either of the commands, test for a short to voltage, short to ground or an open/high resistance on either control circuits. If the circuits test normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

6. If all circuits test normal, test or replace the outside rearview mirror inner actuator.

#### Mirror Position Sensor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate A9 outside rearview mirror.
2. Wait 1 minute, test for less than 10 Ω between the low reference circuit terminal 18 and ground.

⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the appropriate switch.

• | S52 outside mirror switch

• | S79P passenger window switch

3. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.

⇒ | If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the switch.

⇒ | If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

4. Install a 3A fused jumper wire between the signal circuit terminal 5 and the 5 V reference circuit terminal 3. Verify the scan tool Mirror Vertical Position parameter is greater than 4.8 V.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

5. Install a 3A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3. Verify the scan tool Mirror Horizontal Position parameter is greater than 4.8 V.

⇒ | If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

6. Install a 3A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 18. Verify the scan tool Mirror Vertical Position parameter is less than 0.2 V.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

7. Install a 3A fused jumper wire between the signal circuit terminal 1 and the low reference circuit terminal 18. Verify the scan tool Mirror Horizontal Position parameter is less than 0.2 V.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the switch.

• | S52 outside mirror switch

• | S79P passenger window switch

8. If all circuits test normal, test or replace the outside rearview mirror inner actuator.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Outside Rearview Mirror Inner Actuator Replacement

• | Outside Remote Control Rearview Mirror Switch Replacement