• | 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. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Passenger Seat Position Sensor - High | B0084 | B0084 | B0084 | B0084 |
Driver Seat Position Sensor - High | B0083 | B0083 | B0083 | B0083 |
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.
Ignition voltage is between 9-16 volts.
• | The SDM detects the SPS circuit amperage is 4 mA or less for 500 milliseconds. |
• | The SDM detects the SPS circuit amperage is 18 mA or greater for 500 milliseconds. |
• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. |
• | The SDM defaults to disabling stage 2 frontal deployment. |
• | The condition for setting the DTC no longer exists. |
• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred. |
SIR System Description and Operation
Control Module References for scan tool information
Ignition ON, observe the scan tool Driver Seat Position Sensor parameter and Passenger Seat Position Sensor parameter while commanding the appropriate seat BACKWARD and FORWARD, the reading should change between Rearward and Forward.
⇒ | If greater than the specified value, test the circuit for a short to voltage. |
⇒ | If greater than the specified range, test the circuit for a short to voltage. |
⇒ | If less than the specified range, test the signal circuit for a short to ground. |
• | Passenger seat position sensor terminal B and SDM terminal 28. |
• | Driver seat position sensor terminal B and SDM terminal 28. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
• | Passenger seat position sensor terminal A and SDM terminal 30. |
• | Driver seat position sensor terminal A and SDM terminal 29. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
⇒ | If the seat position sensor DTC resets and is current, replace the SDM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for SDM replacement, setup, and programming |