The Driver Door Module (DDM) and Passenger Door Module (PDM) 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. Five 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 DDM/PDM.

Battery voltage must be between 9-16 volts.

B1580

An improper voltage level is seen on the Driver/Passenger Mirror Horizontal Position Sensor Signal circuit.

B1590

An improper voltage level is seen on the Driver/Passenger Mirror Vertical Position Sensor Signal circuit.

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

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

Scan Tool References

Control Module References for scan tool information.

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.

1. Ignition OFF, disconnect the X7 harness connector at the appropriate door module.
2. Ignition ON, verify a test lamp does not illuminate between the following circuit terminals and ground:

•	5-volt reference circuit terminal 7

•	Signal circuit terminal 4

•	Signal circuit terminal 5

•	Low reference circuit terminal 10

⇒	If the test lamp illuminates, test the appropriate circuit for a short to voltage.

3. Ignition OFF, test for infinite resistance between the following circuits and ground:

•	5-volt reference circuit terminal 7

•	Signal circuit terminal 4

•	Signal circuit terminal 5

•	Low reference circuit terminal 10

⇒	If less than the specified value, test the appropriate circuit for a short to ground.

4. Test for 4K-7K ohms between the 5-volt reference circuit terminal 7 and the low reference circuit terminal 10.

⇒	If not within the specified range, test the 5-volt reference circuit and the low reference circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror.

5. Test for 1K-7K ohms between the 5-volt reference circuit terminal 7 and the signal circuit terminal 4.

⇒	If not within the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror.

6. Test for 1K-7K ohms between the 5-volt reference circuit terminal 7 and the signal circuit terminal 5.

⇒	If not within the specified range, test the signal circuit for an open/high resistance. If the circuits test normal, test or replace the rearview mirror.

7. If all circuits test normal, replace the door module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.