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 Circuit | B0084 | B0084 | B0084 | B0084 | B0084
Seat Position Sensor - Right Circuit | 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 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.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

SIR Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

1. With the ignition OFF, disconnect the SPS connector.

⇒ | If DTC B0083 is present, disconnect the right SPS located on the RF outboard seat track.

⇒ | If DTC B0084 is present, disconnect the left SPS located on the LF outboard seat track.

2. Test and inspect the component signal and ground circuits for damage or corrosion.
3. Replace the defective SPS.

⇒ | If DTC B0083 is present, replace the right SPS located on the RF outboard seat track.

⇒ | If DTC B0084 is present, replace the left SPS located on the LF outboard seat track.

4. With the ignition ON, use a scan tool to observe the SIR DTC display. Verify DTC B0083 and/or B0084 is cleared.
5. If DTC does not clear remove the inflatable restraint SDM connector. Inspect the SDM connector for damage or corrosion that may cause a malfunction in the SPS high and/or low circuits.

⇒ | If damage or corrosion is found make the appropriate repair.

6. Test the high and low circuits between the SDM and SPS for a short to voltage, short to ground, or open/low resistance.

⇒ | If circuits test good then 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