GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The seat position sensor circuit consists of the seat position sensor, Seat Position Sensor - High and the Seat Position Sensor - Low circuits and the SDM. The seat position sensor monitors seat position for the SDM. If the SDM detects a malfunction within the seat position sensor circuit, a DTC will be set.

Conditions for Running the DTC

Ignition 1 Voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The SDM detects a seat position sensor malfunction.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • An open or high resistance in the seat position sensor - high or the seat position sensor - low circuits.
    • A short to ground in the seat position sensor - high or the seat position sensor - low circuits.
    • A short to voltage in the seat position sensor - high or the seat position sensor - low circuits.
    • A malfunctioning seat position sensor.
    • An internal SDM malfunction.

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. Tests the Seat Position Sensor - High and the Seat Position Sensor - Low circuits for an open or high resistance.

    Tests the Seat Position Sensor - High and the Seat Position Sensor - Low circuits for a short to ground.

    Tests the Seat Position Sensor - High and the Seat Position Sensor - Low circuits for a short to voltage.

  2. Tests to see if the malfunction is caused by the seat position sensor.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform A Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Is DTC B1153 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

  1. Turn OFF the ignition.
  2. Disconnect the seat position sensor connector.
  3. Inspect both the component and harness sides of the connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Does the connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4

  1. If the component side of the seat position sensor connector is damaged, the seat position sensor must be replaced. Refer to Inflatable Restraint Side Impact Module Replacement - Right Side .
  2. If the harness side of the seat position sensor connector is damaged, replace the harness side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the replacement?

Go to Step 10

--

5

  1. Turn OFF the ignition.
  2. Disconnect the SDM connector.
  3. Inspect the SDM connector for damage or corrosion that may cause a malfunction in the seat position sensor - High and/or the Seat position sensor - Low circuits. 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 10

Go to Step 6

6

  1. Test the Seat position sensor - High and the Seat position sensor - Low circuits for an open or high resistance.
  2. Test the Seat position sensor - High and the Seat position sensor - Low circuits for a short to ground.
  3. Test the Seat position sensor - High and the Seat position sensor - Low circuits for a short to voltage.
  4. All the above conditions refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

  1. Turn OFF the ignition.
  2. Replace the seat position sensor.

Did you complete the replacement?

Go to Step 8

--

8

  1. Reconnect all SIR components.
  2. Verify that all components, connectors and CPAs are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 9

System OK

9

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 10

--

10

  1. Reconnect all SIR components.
  2. Verify that all components, connectors and CPAs are properly mounted.
  3. Use the scan tool in order to Clear the DTCs.
  4. 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