• | 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 | B0012 02 | B0012 0D | B0012 04 | B0012 01 | B0012 0E |
Steering Wheel Module Stage 1 Low | B0012 02 | B0012 0D | B0012 04 | B0012 01 | B0012 0E |
Steering Wheel Module Stage 2 High | B0013 02 | B0013 0D | B0013 04 | B0013 01 | B0013 0E |
Steering Wheel Module Stage 2 Low | B0013 02 | B0013 0D | B0013 04 | B0013 01 | B0013 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 and both steering wheel module stage 2 high circuit and steering wheel module stage 2 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 short to voltage for 120 milliseconds.
The steering wheel module high and/or low circuit is short 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 more 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 commands the AIR BAG indicator ON via serial data communications. |
• | The SDM will store a DTC, if an event occurs the system will still attempt deployments. |
• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used. |
• | A history DTC will clear once 100 malfunction-free ignition cycles have occurred. |
J 38715-A SIR Driver/Passenger Load Tool
This DTC usually indicates a poor connection or a wiring malfunction between the SDM and the deployment loop.
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.
• The pretensioner • The air bag module • The SDM module • The air bag wiring harness connector • The 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 not the specified range, test the circuit for a short to voltage. |
⇒ | If not the specified range, test the circuit for a short to voltage. |
⇒ | If not the specified range, test the circuit for a short to ground. |
⇒ | If not the specified range, test the circuit for a short to ground. |
⇒ | If not the specified range, test the circuit for an open/high resistance. |
⇒ | If not 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 |