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 Descriptors

DTC B1580: Mirror Horizontal Position Sensor Circuit
DTC B1590: Mirror Vertical Position Sensor Circuit

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
5-Volt Reference | B1580, B1590 | B1580, B1590 | B1580, B1590 | --
Driver/Passenger Mirror Horizontal Position Sensor Signal | B1580 | 1 | B1580 | --
Driver/Passenger Mirror Vertical Position Sensor Signal | B1590 | 1 | B1590 | --
Low Reference | -- | B1580, B1590 | -- | --
1. Memory Recall Malfunction

### Circuit/System Description

The Driver Door Switch (DDS) and Passenger Door Switch (PDS) determine the position of the outside rearview mirrors based on inputs from two mirror position sensors, one for vertical position, the other for horizontal position. 5 volts is applied to each sensor through a shared 5-volt reference circuit and a shared low reference circuit supplies ground. Each sensor has an individual signal circuit which provides position voltage to the DDS/PDS.

### Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

### Conditions for Setting the DTC

#### B1580

An improper voltage level is seen on the horizontal position sensor signal circuit.

#### B1590

An improper voltage level is seen the vertical position sensor signal circuit.

### Action Taken When the DTC Sets

Memory 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 malfunction-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

Ignition ON, observe the scan tool Mirror Horizontal Position and Mirror Vertical Position parameters. The reading should be between 0.2-4.8 volts and change as the mirror is moved, left, right, up, and down.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector X1 at the appropriate outside rearview mirror.
2. Ignition OFF, wait 1 minute, test for less than 1.0 ohm between the low reference circuit terminal 10 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 door switch.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 7 and ground.

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

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

4. Install a 3A fused jumper wire between the signal circuit terminal 4 and the 5-volt reference circuit terminal 7. Verify the scan tool Mirror Vertical Position parameter is greater than 4.8 volts.

⇒ | 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 door switch.

5. Install a 3A fused jumper wire between the signal circuit terminal 5 and the 5-volt reference circuit terminal 7. Verify the scan tool Mirror Horizontal Position parameter is greater than 4.8 volts.

⇒ | 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 door switch.

6. Install a 3A fused jumper wire between the signal circuit terminal 4 and the low reference circuit terminal 10. Verify the scan tool Mirror Vertical Position parameter is less than 0.2 volt.

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

7. Install a 3A fused jumper wire between the signal circuit terminal 5 and the low reference circuit terminal 10. Verify the scan tool Mirror Horizontal Position parameter is less than 0.2 volt.

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

8. If all circuits test normal, test or replace the appropriate outside rearview mirror motor.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Outside Rearview Mirror Motor Replacement

• | Control Module References for DDS or PDS replacement, setup, and programming