• | 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 | Low Resistance | High Resistance | Open | Short to Voltage |
---|---|---|---|---|---|
Steering Wheel Module Stage 1 High | B0012 02 | B0012 0E | B0012 0D | B0012 04 | B0012 01 |
Steering Wheel Module Stage 1 Low | B0012 02 | B0012 0E | B0012 0D | B0012 04 | B0012 01 |
Steering Wheel Module Stage 2 High | B0013 02 | B0013 0E | B0013 0D | B0013 04 | B0013 01 |
Steering Wheel Module Stage 2 Low | B0013 02 | B0013 0E | B0013 0D | B0013 04 | B0013 01 |
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 the steering wheel module coil 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 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 request the instrument panel cluster (IPC) to illuminate the AIR BAG indicator ON. |
• | The SIR system is disabled and no deployments are allowed. |
• | The SDM will store a DTC, however 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. |
SIR System Description and Operation
Control Module References for scan tool information
• | J 38715-A SIR Driver/Passenger Load Tool |
• | SA9409Z-A SIR Driver/Passenger Load Tool |
Important:
• Refer to
SIR Service Precautions
. • When removing the connectors inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector: - Pretensioner - Air bag module - SDM - Air bag wiring harness connector - SDM wiring harness connector
Important: The connector and connector position assurance (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 CPA or connector is not properly engaged, make the appropriate repair. |
⇒ | If the DTC is not set or is set as history, cycle ignition OFF, disconnect the adapter and J 38715-A or SA9409Z-A , reconnect the harness connector at the steering wheel module, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the steering wheel module. |
⇒ | If the DTC is not set or is set as history, replace the steering wheel module coil. |
• | Stage 1 terminal 1 |
• | Stage 2 terminal 3 |
⇒ | If greater than the specified range, test the control circuit for a short to voltage. |
• | Stage 1 terminal 2 |
• | Stage 2 terminal 4 |
⇒ | If greater than the specified range, test the control circuit for a short to voltage. |
• | Stage 1 terminal 1 |
• | Stage 2 terminal 3 |
⇒ | If not the specified value, test the control circuit for a short to ground. |
• | Stage 1 terminal 2 |
• | Stage 2 terminal 4 |
⇒ | If not the specified value, test the control circuit for a short to ground. |
• | Steering wheel module coil connector Stage 1 terminal 1 X3 and SDM terminal 9 |
• | Steering wheel module coil connector Stage 2 terminal 3 X3 and SDM terminal 5 |
⇒ | If not within the specified range, test the control circuit for an open/high resistance. |
• | Steering wheel module coil connector Stage 1 terminal 2 X3 and SDM terminal 8 |
• | Steering wheel module coil connector Stage 2 terminal 4 X3 and SDM terminal 4 |
⇒ | If not within 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 |