• | 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 | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Steering Wheel Module Stage 1 High Circuit | B0012 02 | B0012 0D | B0012 04 | B0012 01 | B0012 0E |
Steering Wheel Module Stage 1 Low Circuit | B0012 02 | B0012 0D | B0012 04 | B0012 01 | B0012 0E |
If a malfunction is detected, a DTC will be stored in non-volatile memory. During a frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage.
There are 2 shorting bars used within each connector which will short together both steering wheel module stage 1 high circuit and steering wheel module stage 1 low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing.
Ignition voltage is between 9-16 volts.
The steering wheel module high and/or low circuit is shorted to voltage for 120 milliseconds.
The steering wheel module high and/or low circuit is shorted to ground for 120 milliseconds.
The steering wheel module high and/or low circuit is open for 120 milliseconds.
The steering wheel module deployment loop resistance is greater than 5.1 ohms for 120 milliseconds.
The steering wheel module deployment loop resistance is less than 1.3 ohms for 120 milliseconds.
• | The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator. |
• | The SDM will store a DTC, if an event occurs the system will still attempt deployments. |
• | The condition for setting the DTC no longer exists. |
• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred. |
• | When a harness connector is disconnected, the high control and low control circuits are shorted together by the integral shorting bar. This should be taken into account when testing for faults on these circuits. |
• | This DTC usually indicates a poor connection or a wiring malfunction between the SDM and the deployment loop. |
SIR System Description and Operation
Control Module References for scan tool information
J 38715-A SIR Driver/Passenger Load Tool
Important: When removing connectors inspect for damage, corrosion or poor connection. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
• Pretensioner • Air bag module • SDM module • Air bag wiring harness connector • SDM wiring harness connector
Important: The connector and CPA may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly.
⇒ | If the above condition is found, make the appropriate repair. |
⇒ | If DTC is not set or is set as history, replace the steering wheel module. |
⇒ | If DTC is not set or is set as history, replace the steering wheel module coil. |
⇒ | If greater than the specified range, 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 value, test the circuit for a short to ground. |
⇒ | If less than the specified value, test the circuit for a short to ground. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
⇒ | If greater than the specified range, test the circuit for an open/high resistance. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for SDM replacement, setup, and programming |