Circuit Description
When you first turn ON the ignition, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these tests IGNITION 1, 23VLR and the deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at the driver side low circuit and the passenger side low circuit to detect shorts to B+ in the inflator module circuits.
Conditions for Running the DTC
IGNITION 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | The voltage at the passenger side low circuit is less than 4.8 volts. |
| • | The voltage at the driver side low circuit is more than 4.8 volts for 500 milliseconds. |
Action Taken When the DTC Sets
The SDM turns ON the AIR BAG warning lamp.
Conditions for Clearing the DTC
| • | The voltage at the driver side low circuit is less than 4.8 volts for 500 milliseconds. |
| • | You can issue a CLEAR CODES command. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
Diagnostic Aids
A short to B+ in the inflatable restraint steering wheel module circuit can cause an intermittent condition. Inspect the driver side high circuit and the driver side low circuit for cutting or chafing. The diagnostic table directs the technician to note the entry value of DRIVER SENSELO. Comparing the value of DRIVER SENSELO can be helpful in determining if an intermittent condition exists.
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This step checks the driver side low voltage that was measured by the inflatable restraint sensing and diagnostic module (SDM).
-
This step isolates the malfunction to one side of the inflatable restraint steering wheel module coil yellow 2-way connector.
-
This step determines if there is a malfunctioning inflatable restraint steering wheel module coil or if there is a malfunctioning inflatable restraint steering wheel module.
-
This step checks to see if there is a short to B+ in the driver side high circuit.
-
This step determines if there is a short to B+ in the driver side low circuit or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the SIR Diagnostic System Check? | -- | ||
Has the DRIVER SENSELO been read and recorded on the repair order? | -- | -- | ||
Is DRIVER SENSELO more than the specified value? | 4.8 V | |||
Is DRIVER SENSELO more than the specified value? | 4.8 V | |||
5 |
Did you complete the repair? | -- | -- | |
6 |
Did you complete the repair? | -- | -- | |
Is the measured voltage less than the specified value? | 1.0 V | |||
8 |
Did you complete the repair? | -- | -- | |
Use the J 39200 to measure the voltage between the driver side low circuit and the ground circuit of the SDM wiring harness connector. Is the measured voltage less than the specified value? | 1.0 V | |||
10 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the repair? | -- | -- | |
11 |
Did you complete the repair? | -- | -- | |
12 |
Did you complete the action? | -- | -- |
