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.
Deployment loop voltage out of range test:
• | Ignition 1 voltage is within the normal operating voltage range. |
• | Driver seat belt pretensioner deployment loop is not shorted to voltage. |
• | Driver belt high terminal C1 is less than 2 volts. |
Deployment loop resistance measurement test:
• | Ignition 1 voltage is within the normal operating voltage range. |
• | Driver seat belt pretensioner deployment loop is not shorted to voltage. |
• | Driver seat belt pretensioner deployment loop is not shorted to ground. |
Deployment loop voltage out of range test - Driver seat belt pretensioner deployment loop resistance is at least 6 ohms for 300 milliseconds.
Deployment loop resistance measurement test - Driver seat belt pretensioner deployment loop resistance is more than 3.7 ohms for 300 milliseconds.
The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
• | You can issue a CLEAR CODES command |
• | A history DTC will clear once 255 malfunction free ignition cycles have occurred |
The following can cause an intermittent condition:
• | The driver seat belt pretensioner yellow 2-way connector. |
• | The SDM wiring harness connector. |
• | The wire to terminal connections in the driver belt high circuit. |
• | The wire to terminal connections in the driver belt low circuit. |
• | Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. |
The number(s) below refer to the step number(s) on the diagnostic table.
This step checks the driver seat belt pretensioner yellow 2-way connector.
This step checks to see if there is a malfunctioning driver seat belt pretensioner.
This step checks to see if there is an open or a high resistance in the driver belt high circuit.
This step determines if there is an open or a high resistance in the driver belt low circuit or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform A Diagnostic System Check - SIR? | -- | Go to Step 2 | |||||||
Does either the component or harness side of the driver seat belt pretensioner yellow 2-way connector exhibit any signs of corrosion, terminal damage, or poor connections? | -- | Go to Step 3 | Go to Step 4 | |||||||
3 |
Did you complete the repair? | -- | Go to Step 12 | -- | ||||||
4 |
Does the scan tool indicate that this DTC is current? | -- | Go to Step 5 | Go to Diagnostic Aids | ||||||
Does the scan tool indicate that this DTC is current? | -- | Go to Step 7 | Go to Step 6 | |||||||
6 |
Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
Does the resistance measure less than the specified value? | 0.5 ohms | Go to Step 9 | Go to Step 8 | |||||||
8 | Locate and repair the open or the high resistance in the driver belt high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | -- | ||||||
Use the DMM to measure the resistance of the driver belt low circuit. Does the resistance measure less than the specified value? | 0.5 ohms | Go to Step 11 | Go to Step 10 | |||||||
10 | Locate and repair the open or the high resistance in the driver belt low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | -- | ||||||
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- | ||||||
12 |
Did you complete the action? | -- | -- |