GM Service Manual Online
For 1990-2009 cars only

Object Number: 97857  Size: MF
Power Door Systems Components
Door Control Module Schematics
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

The RH Door Control Module (RDCM) provides the RH mirror motor control output functions. This output control allows the RDCM to command the RH power mirror in the horizontal or vertical position. The LH door switch circuit provides an input to the LDCM when the mirror switch is pressed UP, DOWN, LEFT or RIGHT. When the LDCM detects an active mirror command from mirror switch, the LDCM will send a message on the serial data line to the RDCM, the RDCM will command the RH window motor in the appropriate direction. The RDCM accomplishes this by applying a ground or voltage to CKT 889 and CKT 1498 (vertical motor), or CKT 90 and CKT 881 (horizontal motor), depending on the desired mirror position. The RDCM monitors the amount of current draw on both RH the horizontal and vertical mirror motor control circuits. If the current draw is not within the acceptable range, a malfunction is present and a DTC will set.

Conditions for Setting the DTC

    • The RDCM commands the horizontal or vertical mirror motor ON.
    • The RDCM detects a high current or short to voltage condition in the RH horizontal or vertical mirror motor control circuit.
    • The RDCM detects battery 1 voltage under 7.9 volts with the RH horizontal or vertical mirror motor is applied.
    • Condition must be present for 2 seconds.

Action Taken When the DTC Sets

    • Stores a history DTC B2273 in the RDCM memory.
    • This DTC can only be set as a history code even if the malfunction is current.
    • No driver warning message will be displayed for this DTC.

Conditions for Clearing the DTC

    • The RDCM no longer detects a high current or short to voltage condition in the RH horizontal or vertical mirror motor control circuit for longer than 2 seconds.
    • Use the IPC clearing DTCs feature.
    • Use a scan tool.

Diagnostic Aids

    • The following conditions may cause an intermittent malfunction:
       - There is an intermittent short to voltage in the RH vertical or horizontal mirror motor control circuit.
       - The RH vertical or horizontal mirror motor is shorted internally.
    • If the horizontal or vertical motor circuit is shorted (to ground or voltage), the RH mirror will operate only in certain directions depending on what circuit was affected.
    • Using a scan tool, select RDCM inputs and monitor the mirror motor load while operating the mirror motor in all directions. If the scan tool displays the mirror motor load as 0, then check the mirror motor circuit for opens.
    • If the DTC does not reset after the code is cleared, then the problem may be intermittent. Perform the tests shown while moving related wiring and connectors. This can often cause the malfunction to occur. Refer to Intermittents and Poor Connections .

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This test determines if the malfunction is located in the RH mirror horizontal motor circuit or the RH mirror vertical motor circuit.

  2. This test checks if the RDCM is sending the correct supply voltage to the RH vertical mirror motor.

  3. This test checks if the RDCM is sending the correct supply voltage to the RH horizontal mirror motor.

DTC B2273

Step

Action

Value(s)

Yes

No

1

Were you sent here from the Power Door Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Power Door Systems

2

Using the LH door switch, select RH mirror and operate the RH mirror LEFT and RIGHT.

Does the RH outside rearview mirror move LEFT and RIGHT?

--

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition switch.
  2. Disconnect the RH mirror connector C1.
  3. Turn ON the ignition switch.
  4. At the RH mirror connector C1 (harness side), measure the voltage between terminals A and C while operating the RH mirror UP and DOWN.

Is the voltage within the specified range in the UP and DOWN positions?

10.0-14.0 V

Go to Step 9

Go to Step 5

4

  1. Turn OFF the ignition switch.
  2. Disconnect the RH mirror connector C1.
  3. Turn ON the ignition switch.
  4. At the RH mirror connector C1 (harness side), measure the voltage between terminals H and F while operating the RH mirror LEFT and RIGHT.

Is the voltage within the specified range in the LEFT and RIGHT positions?

10.0-14.0 V

Go to Step 9

Go to Step 6

5

Check for an open or short (to ground or voltage) in CKT 1498 or CKT 889.

Was a problem found and repaired?

--

Go to Step 10

Go to Step 8

6

Check for an open or short (to ground or voltage) in CKT 881 or CKT 90.

Was a problem found and repaired?

--

Go to Step 10

Go to Step 8

7

Replace the RH mirror assembly. Refer to Outside Rearview Mirror Replacement .

Is the replacement complete?

--

Go to Step 10

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8

  1. Replace the RDCM. Refer to Door Control Module Replacement .
  2. Program the replacement DCM (hardtop only). Refer to Door Control Module Programming/RPO Configuration .

Is the replacement complete?

--

Go to Step 10

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9

Check both the mirror horizontal and vertical position sensor circuits for an intermittent malfunction. Refer to Diagnostic Aids.

Was a problem found and repaired?

--

Go to Step 10

Go to Step 7

10

  1. Turn OFF the ignition switch.
  2. Reconnect or install any connectors or components that were disconnected or removed.
  3. Turn ON the ignition switch.
  4. Clear any DTCs.

Is the repair complete?

--

Go to Diagnostic System Check - Power Door Systems

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