GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Express - AWD 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B0083 or B0084

Circuit Description

The inflatable restraint seat position sensor (SPS) is used to determine the proximity of a front driver or passenger seat position with respect to the frontal air bag. The SPS interfaces with the sensing and diagnostic module (SDM). The state of the SPS allows the SDM to disable stage 2 of the frontal air bag for a front seat that is forward of a forward/rearward point in seat track travel. The SPS is a Hall effect sensor that is mounted on the seat track of both the driver and passenger seats. The seat track includes a metal bracket that shunts the SPS magnetic circuit creating 2 states of seat position. The shunted state represents a rearward seat position. The non-shunted state represents a forward position. The SPS provides 2 current ranges, one range for the shunted state and a second range for a non-shunted state. These 2 states are inputs to the SDM. State 1 (shunted) being the rearward threshold and state 2 (non-shunted) being the forward threshold. When the SDM receives input from a SPS that state 1 threshold is reached (seat is rearward) the SDM will not disable stage 2 deployment, if required by the deployment sensors. When state 2 threshold is reached (seat is forward) the SDM will disable stage 2 deployment on the side the seat is forward. The SDM monitors the SPS circuit and if a fault is detected the SDM will set codes B0083 or B0084 and defaults to disabling stage 2 frontal deployment. This will only default on the side of the vehicle the sensor has a fault. Its important to understand that the SPS is secondary to the passenger presence system (PPS) and the manual instrument panel module (IPM) disable switch. If either one of these devices are in the disable mode the passenger air bag will not deploy regardless of the SPS status.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

    • DTC B0083 Right Front/Passenger Seat Position Sensor Circuit
    • DTC B0084 Left Front/Driver Seat Position Sensor Circuit

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

DTC B0083 and B0084 will set when one of the following conditions occur:

    • The SDM detects the SPS circuit amperage is 4 mA or less for 500 milliseconds.
    • The SDM detects the SPS circuit amperage is between 8-11 mA for 500 milliseconds.
    • The SDM detects the SPS circuit amperage is 18 mA or greater for 500 milliseconds.

Action Taken When the DTC Sets
    • The SDM commands the AIR BAG indicator ON via class 2 serial data.
    • The SDM defaults the SPS to seat forward threshold.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists.
    • You issue a scan tool CLEAR DTCs command.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

The following can cause an intermittent condition:

    • A short between the SPS signal and low reference circuits
    • High or low resistance in the SPS signal and low reference circuits
    • Inspect the SPS signal and return circuits carefully for cutting and/or chafing

Refer to Testing for Intermittent Conditions and Poor Connections .

Test Description

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

  1. This step inspects the SPS connector and terminals.

    2.

  2. This step tests for a short to ground, a high resistance, or an open in the SPS signal circuit.

    3.

  3. This step tests for a short to ground, a high resistance, or an open in the SPS low reference circuit.

    4.

  4. This step tests for a short to voltage in the SPS signal and low reference circuits.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn OFF the ignition.
  2. If DTC B0083 is present disconnect the right seat position sensor (SPS) located on the RF inboard seat track. If DTC B0084 is present disconnect the left SPS located on the LF outboard seat track.
  3. Inspect both the SPS and harness connector terminals for the following conditions:
    4. • Corrosion
    • Terminal damage
    • Poor connections/terminal tension

Do the SPS terminals or harness connector exhibit any signs of corrosion, terminal damage, or poor connections?

Go to Step 3

Go to Step 4

3
    • If the SPS terminals are damaged, replace the SPS. Refer to Inflatable Restraint Seat Position Sensor Replacement .
    • If the SPS harness connector is damaged, replace the connector. Refer to Connector Repairs .

Did you complete the replacement?

Go to Step 12

--

4
  1. If DTC B0083 is present disconnect the right main seat harness connector-located under the RF seat. If DTC B0084 is present disconnect the left main seat harness connector-located under the LF seat. Refer to Power Seat Connector End Views .
  2. Inspect both halves of the connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 5

5
  1. Disconnect the sensing and diagnostic module (SDM) connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Inspect the SDM connector for corrosion or damage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 6

6

    • If DTC B0083 is current, test the right SPS signal circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .
    • If DTC B0084 is current, test the left SPS signal circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 7

7

    • If DTC B0083 is current, test the right SPS low reference circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .
    • If DTC B0084 is current, test the left SPS low reference circuit for a short to ground, a high resistance, or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 8

8

  1. Turn ON the ignition, with the engine OFF.
  2. If DTC B0083 is current, test the right SPS signal and low reference circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
  3. If DTC B0084 is current, test the left SPS signal and low reference circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 9

9

For DTC B0083 replace the right SPS. For DTC B0084 replace the left SPS. Refer to Inflatable Restraint Seat Position Sensor Replacement .

Did you complete the replacement?

Go to Step 10

--

10
  1. Reconnect all SIR system components.
  2. Use the scan tool in order to clear the DTCs.
  3. Operate the vehicle within the Conditions for Running the DTC, as specified in the supporting text.

Does the DTC reset?

Go to Step 11

System OK

11

Replace the SDM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

12
  1. Reconnect all SIR system components.
  2. Verify that all components, connectors and connector position assurances (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