The LF/driver seat belt pretensioner deployment loop is a 2 wire circuit. 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.
• | The ignition 1 voltage is within the normal operating voltage range. |
• | The LF pretensioner deployment loop is not shorted to voltage. |
• | The LF pretensioner high terminal is more than 2.4 volts. |
Deployment loop resistance measurement test:
• | The ignition 1 voltage is within the normal operating voltage range. |
• | The LF pretensioner deployment loop is not shorted to voltage. |
• | The LF pretensioner deployment loop is not shorted to ground. |
• | Deployment loop voltage out of range test - The LF pretensioner high is less than 2.4 volts, the LF pretensioner loop resistance is greater or equal to 6 ohms for 500 milliseconds. |
• | Deployment loop resistance measurement test - The LF pretensioner deployment loop resistance is more than 4.8 ohms for 500 milliseconds. |
The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.
• | The LF pretensioner deployment loop resistance is 4.8 ohms or less for 500 milliseconds. |
• | The LF pretensioner high is more than 2.4 volts, the LF pretensioner 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. |
The following can cause an intermittent condition:
• | The LF pretensioner harness connector |
• | The SDM wiring harness connector |
• | The wire to terminal connections in the LF pretensioner high circuit |
• | The wire to terminal connections in the LF pretensioner low circuit |
If any of the above conditions are found 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 LF/driver seat belt pretensioner in-line connector.
This step checks to see if there is a malfunctioning LF pretensioner.
This step checks to see if the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector is OK.
This step checks to see if there is an open or a high resistance in the LF pretensioner high deployment circuit.
This step determines if there is an open or high resistance in the LF pretensioner low deployment circuit or if there is a malfunctioning SDM.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check? | -- | Go to Step 2 | |||||||
Do the connectors exhibit any signs of corrosion, terminal damaged, or poor connections? | -- | Go to Step 3 | Go to Step 4 | |||||||
3 | Replace the vehicle wiring harness side of the in-line connector. Refer to Connector Repairs in Wiring Systems. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
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 14 | -- | ||||||
Is the SDM wiring harness connector OK? | -- | Go to Step 9 | Go to Step 8 | |||||||
8 | Repair or replace the SDM wiring harness connector. Refer to Connector Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||
Use the J 39200 DMM and measure the resistance between the LF pretensioner high deployment circuit in-line connector terminal and the SDM wiring harness connector terminal. Does the resistance measure greater than the specified value? | 0-0.5 ohms | Go to Step 10 | Go to Step 11 | |||||||
10 | Locate and repair the open or high resistance in the LF pretensioner high deployment circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||
Use the J 39200 and measure the resistance between the LF pretensioner low deployment circuit in-line connector terminal and the SDM wiring harness connector terminal. Does the resistance measure greater than the specified value? | 0-0.5 ohms | Go to Step 12 | Go to Step 13 | |||||||
12 | Locate and repair the open or high resistance in the LF pretensioner low deployment circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 14 | -- | ||||||
13 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 14 | -- | ||||||
14 |
Did you complete the action? | -- | -- |