GM Service Manual Online
For 1990-2009 cars only

Object Number: 456294  Size: MF
Handling ESD Sensitive Parts Notice
Power Seat Systems Components
Memory Seats Schematics
Power Seat Connector End Views

Circuit Description

The memory seat module (MSM) receives inputs from the left seat switch. When you operate a switch, the switch grounds. The MSM recognizes the input. The MSM then moves the seat in the appropriate direction. When any seat positioning switch continues to activate for 30 seconds after motion stops in the direction requested, the system considers the switch shorted. The system also considers a switch shorted under the following conditions:

    • A seat position sensor DTC is currently set.
    • A switch in the direction of the faulty sensor is active for over 30 seconds.

Conditions for Setting the DTC

The MSM sets the appropriate DTC any time the MSM detects a switch failure.

Action Taken When the DTC Sets

    • Motor outputs driven in response to the faulty switch deactivate.
    • The MSM continues to respond to valid inputs from all other positioning switches.
    • The MSM ignores all memory recall commands.

Conditions for Clearing the DTC

The DTC clears when the MSM does not detect the switch failure for the last monitoring cycle.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. This test determines if there is a stuck switch or a short to ground in the input wiring to the memory seat module (MSM). If there is a short to ground in the wiring, the DTC will set again. If there is a stuck switch, the DTC will not set again because the left seat switch is disconnected.

Step

Action

Value(s)

Yes

No

1

Did you perform the Power Seat Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Power Seat Systems

2

  1. Disconnect the left seat switch.
  2. Connect a Scan Tool to the data link connector (DLC).
  3. Turn the ignition switch to the RUN position.
  4. Use the Scan Tool in order to clear all DTCs.
  5. Wait 30 seconds.

Does the DTC set again?

--

Go to Step 3

Go to Step 4

3

Repair the short to ground in CKT 1519 (YEL). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step 5

--

4

Replace the left seat switch. Refer to Power Seat Switch Replacement .

Is the left seat switch replacement complete?

--

Go to Step 5

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5

  1. Clear the DTCs from memory. Refer to Diagnostic Trouble Code (DTC) Clearing .
  2. Perform the Diagnostic System Check. Refer to Diagnostic System Check - Power Seat Systems .

Did you clear the DTCs and perform the Power Seat Systems Diagnostic System Check?

--

Go to Diagnostic System Check - Power Seat Systems

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