GM Service Manual Online
For 1990-2009 cars only

Object Number: 501158  Size: MF
Power Seat Systems Components
Seat Front Vertical, Seat Rear Vertical, and Seat Horizontal POSiTion Sensors and Motors

Circuit Description

The memory seat module (MSM) supplies a 5 volt reference voltage to all of the seat position sensors from connector C1 cavity 13 (GRY).

Conditions for Setting the DTC

The 5-volt feed voltage falls out of the range of 4.6-5.2 volts.

Action Taken When the DTC Sets

The MSM does not allow any memory recall function. Only manual seat movement is allowed. Only one seat motor moves at a time.

Conditions for Clearing the DTC

The 5-volt feed voltage is within a valid operating range during the last monitoring cycle.

Test Description

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

  1. This step tests for an open or short to ground in CKT 788 (GRY).

  2. This step tests for a short to battery positive voltage (B+) in CKT 788 (GRY).

Step

Action

Value(s)

Yes

No

1

Was the entire Power Seat Systems Diagnostic System Check performed?

--

Go to Step  2

Go to Diagnostic System Check - Power Seat Systems

2

  1. Turn OFF the ignition switch.
  2. Disconnect the front vertical position sensor connector.
  3. Connect a J 39200 digital multimeter (DMM) from the front vertical position sensor cavity B (GRY) to ground.

Is the voltage near the specified value?

0 V

Go to Step  5

Go to Step  3

3

Is the voltage near the specified value?

12 V

Go to Step  6

Go to Step  4

4

Replace the MSM. Refer to Memory Seat Control Module Replacement .

Is the MSM replacement complete?

--

Go to Step  7

--

5

Repair the open or short to ground in CKT 788 (GRY). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step  7

--

6

Repair the short to battery positive voltage (B+) in CKT 788 (GRY). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

--

Go to Step  7

--

7

Clear the DTCs from memory. Refer to Diagnostic Trouble Code (DTC) Clearing .

Are all DTCs cleared?

--

Go to Diagnostic System Check - Power Seat Systems

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