For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

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

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Seat Position Sensor - Left Control | B0084 | B0084 | B0084 | B0084 | B0084
Seat Position Sensor - Right Control | B0083 | B0083 | B0083 | B0083 | B0083

### Circuit/System 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 near 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 (I/P) module 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.

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### 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 requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.

• | The SDM defaults the SPS to seat forward threshold.

### Conditions for Clearing the DTC

• | The condition for setting the DTC no longer exists.

• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

SIR System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information.

### Circuit/System Testing

Important: When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:

• | Seat position sensor (SPS)

• | SDM

• | Seat position sensor wiring harness connector

• | SDM wiring harness connector

1. Ignition OFF, disconnect the harness connector at the appropriate SPS.
2. Disconnect the harness connector at the SDM.
3. Ignition ON, test for less than 1 volt between the appropriate signal circuit listed below and ground:

• | Driver SPS signal circuit terminal 24.

• | Passenger SPS signal circuit terminal 25.

⇒ | If greater than the specified range, test the signal circuit for a short to voltage.

4. Ignition ON, test for less than 1 volt between the low reference circuit terminal 11 and ground.

⇒ | If greater than the specified range, test the low reference circuit for a short to voltage.

5. Ignition ON, test for infinite resistance between the appropriate signal circuit listed below and ground:

• | Driver SPS signal circuit terminal 24.

• | Passenger SPS signal circuit terminal 25.

⇒ | If less than infinite resistance, test the signal circuit for a short to ground.

6. Test for less than 1 ohm between the appropriate signal circuit terminals listed below:

• | Driver SPS signal circuit terminal 24 at the SDM and terminal A at the sensor.

• | Passenger SPS signal circuit terminal 25 at the SDM and terminal A at the sensor.

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance.

7. Test for less than 1 ohm between the appropriate low reference circuit terminals listed below:

• | Driver SPS low reference circuit terminal 11 at the SDM and terminal B at the sensor.

• | Passenger SPS low reference circuit terminal 11 at the SDM and terminal B at the sensor.

⇒ | If greater than the specified range, test the signal circuit for an open/high resistance.

8. If all circuits test normal, replace the SPS and verify that the DTC does not reset.

⇒ | If the DTC resets, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Inflatable Restraint Seat Position Sensor Replacement

• | SIR/SRS Wiring Repairs

• | Control Module References for SDM replacement, setup, and programming