GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The mobility seat module uses inputs from 4 limit switches in order to determine the seat position. The limit switch signal circuits are referenced from battery voltage within the module. The limit switches will open or close the switch signal circuits to ground in order for the module to determine them to be active or inactive. The swivel out limit switch signal circuit is considered to be active when the circuit reference voltage is low or closed to ground by the switch. The mobility seat module also monitors an input from a hall effect sensor in the rotation motor while the seat is being rotated in or out. The hall effect is a 12-volt 3-wire sensor and the signal circuit is referenced from battery voltage within the module.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC 023 Swivel Out Limit Becomes Active Before Rotation Out Is Complete

Conditions for Running the DTC

    • Battery voltage must be within 9-16 volts.
    • Seat operation is attempted from the forward facing position.

Conditions for Setting the DTC

When rotating the seat to the outward position the swivel out limit switch becomes active before the hall effect sensor input indicates that the seat has rotated to the full outward facing position.

Action Taken When the DTC Sets

While the fault is current the module will not allow the seat to be extended outward but will allow rotation inward to the forward facing position.

Conditions for Clearing the DTC

The DTC may be cleared by removing the main power supply or ground from the seat module.

Diagnostic Aids

Inspect the limit switch for any physical damage or obstructions to its mechanical operation which may cause the condition.

Step

Action

Yes

No

Schematic Reference: Passenger Seat Schematics

Connector End View Reference: Power Seat Connector End Views

1

Did you review the description operation and perform the necessary inspections?

Go to Step 2

Go to Power Seats System Description and Operation

2

Verify the fault is present.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Attempt to operate the seat to the outward facing position.

Does the seat rotate to the swivel out hard stop?

Go to Step 4

Go to Step 5

4

  1. Return the seat to the forward facing position.
  2. Remove the 25-amp circuit breaker for several seconds.
  3. Operate the seat from the forward facing position to the out of vehicle position 2 times.

Does the DTC reset?

Go to Step 6

Go to Step 8

5

Test the swivel out limit switch for a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 8

Go to Step 7

6

Replace the mobility seat control module. Refer to Sit-N-Lift Control Module Replacement .

Is the repair complete?

Go to Step 8

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7

Replace the mobility seat base unit. Refer to Sit-N-Lift Seat Base Replacement .

Is the repair complete?

Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3