GM Service Manual Online
For 1990-2009 cars only

Circuit Description

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 .

DTC Descriptors

This diagnostic procedure supports the following DTCs:

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

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

These DTCs will set if:

    • A mirror position sensor signal voltage is below 0.5 volts for 2 seconds.
    • A mirror position sensor signal voltage is above 4.5 volts for 2 seconds.

Action Taken When the DTC Sets

    • The door module will ignore the failed position sensor.
    • The door module will ignore memory set or recall for the mirrors.
    • Manual mirror movements will be allowed.

Conditions for Clearing the DTC

    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.

Diagnostic Aids

    • If DTC B1580 and B1590 are both set, the low reference circuit may be open, or the 5-volt reference circuit may be open, short to ground or short to voltage.
    • Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Value(s)

Yes

No

Schematic Reference: Outside Rearview Mirror Schematics and Door Control Module Schematics

Connector End View Reference: Power Door Systems Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the appropriate mirror position parameter in the appropriate door module data list.

Does the scan tool indicate that the mirror position parameter is within the specified range?

0.5-4.5 V

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Disconnect the appropriate outside rearview mirror C2 harness connector.

Does the scan tool indicate that the mirror position parameter is greater than specified?

4.5 V

Go to Step 8

Go to Step 4

4

Measure the voltage from the 5-volt reference circuit of the door harness connector to a good ground.

Does the voltage measure near the specified value?

5 V

Go to Step 6

Go to Step 5

5

Does the voltage measure greater than the specified value?

5 V

Go to Step 9

Go to Step 10

6

Measure the voltage between the 5-volt reference circuit and the low reference circuit of the door harness connector.

Does the voltage measure near the specified value?

5 V

Go to Step 7

Go to Step 11

7

Connect a 3-amp fused jumper wire between the 5-volt reference circuit and the appropriate signal circuit of the door harness connector.

Does the scan tool indicate that the mirror position parameter is greater than specified?

4.5 V

Go to Step 13

Go to Step 12

8

Test the appropriate mirror position signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

9

Test the appropriate 5-volt reference circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

10

Test the appropriate 5-volt reference circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

11

Test the appropriate low reference circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

12

Test the appropriate mirror position signal circuit for a short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 14

13

Inspect for poor connections at the harness connectors of the appropriate mirror. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 15

14

Inspect for poor connections at the C2 harness connector of the appropriate door module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 17

Go to Step 16

15

Replace the appropriate mirror. Refer to Mirror, Mirror Face Replacement - Front Door .

Did you complete the replacement?

--

Go to Step 17

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16

Replace the appropriate door module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup and programming.

Did you complete the replacement?

--

Go to Step 17

--

17

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK