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

The driver door module (DDM) and passenger door module (PDM) receive mirror position signals from the mirror horizontal and vertical position sensors. These signals are used by the door modules for memory recall functions of the driver and passenger mirrors. The door modules command the mirror memory settings based upon the voltage level received back from the position sensors. Each door module provides a 5 volt supply, a signal, and ground circuit for each of the position sensors. The horizontal and vertical position sensors are variable resistors that the door modules monitor voltage levels across. When a memory setting is recalled, the door modules command the mirror motors in the appropriate directions until the stored position sensor voltage levels are achieved. The DDM and PDM monitor the signal circuits to determine if the voltage level is out of range. For more detailed information concerning power mirror operation refer to Outside Mirror Description and Operation .

Battery voltage must be between 9-16 volts.

These DTCs will set if:

If DTC B1580 and B1590 are both set, the low reference circuit may be open, or the 5-volt reference circuit may be open, shorted to ground, or shorted to voltage.

Schematic Reference

Outside Rearview Mirror Schematics

Connector End View Reference

Power Door Systems Connector End Views

Electrical Information Reference

Scan Tool Reference

1. Ignition OFF, disconnect the appropriate outside rearview mirror C2 harness connector.
2. Ignition OFF, test for less than 1.0 ohm of resistance between the low reference circuit terminal 7 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 control module.

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

⇒	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 appropriate door control module.

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

4. Verify with a scan tool the appropriate mirror position parameter is less than 4.5 volts.

⇒	If greater than the specified range, test the appropriate mirror position signal circuit for a short to voltage. If the circuit tests normal, replace the appropriate door control module.

5. Install a 3-A fused jumper wire between the appropriate mirror position signal circuit and the 5-volt reference circuit terminal 3. Verify with a scan tool the appropriate mirror position parameter is greater than 4.5 volts.

⇒	If less than the specified range, test the appropriate mirror position signal circuit for short to ground or an open/high resistance. If the circuit tests normal, replace the appropriate door control module.

6. If all circuits test normal, test or replace the appropriate mirror.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.