Circuit Description
The ignition switch supplies ignition 1 voltage to the inflatable restraint sensing and diagnostic module (SDM) using the AIR BAG fuse. The ignition switch also supplies battery voltage to the AIR BAG indicator using the IG fuse. The AIR BAG indicator is connected to the AIR BAG indicator output of the SDM. When the ignition switch is first turned to the ON position, the SDM responds by flashing the AIR BAG indicator seven times. If the ignition 1 voltage is outside of the normal operating voltage range (9.0 - 16.0 volts) for more than 25 ms, the AIR BAG indicator will turn ON with no DTCs set.
Diagnostic Aids
In order to disable the shorting bar between the air bag indicator control circuit and ground inside the SDM wiring harness connector, the following two conditions must be met:
| • | The SDM wiring harness connector must be properly connected to the SDM. |
| • | The connector position assurance (CPA) must be properly installed in the SDM wiring harness connector. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: SIR Schematics | ||||
1 | Did you perform A Diagnostic System Check - SIR? | -- | Go to Step 2 | |
Does the scan tool indicate that the Ignition Voltage parameter is greater than the specified value? | 16.0 V | Go to Symptoms - Engine Electrical in Engine Electrical | Go to Step 3 | |
3 |
Did you find and correct the condition? | -- | Go to Step 6 | Go to Step 4 |
4 | Test the Air Bag Indicator Control circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 6 | Go to Step 5 |
5 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 6 | -- |
6 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 2 |
