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. Then the SDM performs the following continuous diagnostic tests on the deployment loops:
| • | Deployment loop voltage out of range test |
| • | Deployment loop resistance measurement test |
If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.
Conditions for Running the DTC
Deployment loop voltage out of range test - Ignition 1 voltage is within the normal operating voltage range.
Deployment loop resistance measurement test:
| • | Ignition 1 voltage is within the normal operating voltage range. |
| • | Driver frontal deployment loop is not shorted to voltage. |
Conditions for Setting the DTC
| • | Deployment loop voltage out of range test - Driver frontal high terminal is greater than 6 volts for 500 milliseconds. |
| • | Deployment loop resistance measurement test - Driver frontal high terminal is less than 2.4 volts and driver frontal deployment loop resistance is less than 6 ohms for 500 milliseconds. |
Action Taken When the DTC Sets
The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
Conditions for Clearing the DTC
| • | Driver frontal high terminal is less than or equal to 6 volts for 500 milliseconds. |
| • | Driver frontal high terminal is greater than or equal to 2.4 volts and driver frontal deployment loop resistance is less than 6 ohms 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
The following can cause an intermittent condition:
| • | A short to ground or to voltage on either of the two sides of the deployment loop circuit can cause a intermittent condition. |
| • | Inspect the driver frontal high and driver frontal low circuits carefully for cutting or chafing or any type of wire damage. |
| • | Wiring pigtail damage requires replacement of the inflatable restraint steering wheel module coil. |
If any of the above conditions are found refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
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This step checks the driver inflator module in-line connector below the steering wheel restraint module coil.
-
This step test for the proper operation of inflatable restraint steering wheel module coil and/or inflatable restraint steering wheel inflator module.
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This step checks to see if there is a short to ground in the driver frontal high deployment circuit.
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This step checks to see if there is a short to ground in the driver frontal low deployment circuit.
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This step checks to see if there is a short to voltage in the driver frontal high deployment circuit.
-
This step determines if there is a short to voltage in the driver frontal low deployment circuit, or if there is a malfunctioning SDM.
-
This step clears all SIR DTC's.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check? | -- | ||||||||
Does connector exhibits any signs of corrosion, terminal damaged, or poor connections? | -- | |||||||||
3 |
Did you complete the replacement? | -- | -- | |||||||
4 |
Does the scan tool indicate that this DTC is current? | -- | Go to Diagnostic Aids | |||||||
5 |
Does the scan tool indicate that this DTC is current? | -- | ||||||||
Does the scan tool indicate that this DTC is current? | -- | |||||||||
7 |
Did you complete the replacement? | -- | -- | |||||||
8 |
Did you complete the replacement? | -- | -- | |||||||
Does the resistance measure less than the specified value? | OL | |||||||||
10 | Locate and repair a short to ground in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||||
Use the J 39200 and measure the resistance between SDM wiring harness connector driver frontal low circuit and a known good ground. Does the resistance measure less than the specified value? | OL | |||||||||
12 | Locate and repair a short to ground in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||||
Does the voltage measured less than the specified value? | 1 V | |||||||||
14 | Locate and repair a short to voltage in the driver frontal high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||||
Use the J 39200 and measure the voltage between SDM wiring harness connector driver frontal low circuit and a known good ground. Does the voltage measured less than the specified value? | 1 V | |||||||||
16 | Locate and repair a short to voltage in the driver frontal low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | -- | |||||||
17 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | -- | |||||||
Did you complete the action? | -- | -- |
