Circuit Description
The seat belt pretensioner deployment loop consists of a seat belt pretensioner, the seat belt pretensioner high and seat belt pretensioner low circuits. A shorting bar is used in the seat belt pretensioner connector, which will short together the seat belt pretensioner high and seat belt pretensioner low circuits, when the connector is disconnected. This will help to prevent unwanted deployment of the seat belt pretensioner during servicing. During a frontal crash of sufficient force, the sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the seat belt pretensioner. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity, and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored.
DTC Descriptor
This diagnostic procedure supports the following DTCs:
DTC 0049 LF Pretensioner Deployment Loop Short to Battery
DTC 0050 LF Pretensioner Deployment Loop Voltage Out of Range
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | DTC 0049 will set when the SDM detects a short to voltage in the LH seat belt pretensioner deployment loop. |
| • | DTC 0050 will set when the SDM detects a short to ground in the LH seat belt pretensioner deployment loop. |
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON.
Conditions for Clearing the DTC
The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.
The following are possible causes of the malfunction:
| • | A short to voltage in the seat belt pretensioner high or the seat belt pretensioner low circuits |
| • | A short to ground in the seat belt pretensioner high or the seat belt pretensioner low circuits |
| • | A malfunctioning LH seat belt pretensioner |
| • | An internal SDM malfunction |
If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the seat belt pretensioner high and the seat belt pretensioner low circuits for a short to voltage.
-
This step tests to see if the malfunction is caused by the LH seat belt pretensioner.
-
This step tests the seat belt pretensioner high and the seat belt pretensioner low circuits for a short to ground.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | ||||
1 | Did you perform a Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 | Is DTC 0049 or 0050 set as a current DTC? | -- | Go to Step 3 | Go to Diagnostic Aids |
3 | Is DTC 0049 set as a current DTC? | -- | Go to Step 4 | Go to Step 5 |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | |
5 | Is DTC 0050 set as a current DTC? | -- | Go to Step 6 | -- |
6 | Use the scan tool to display the LH Pretensioner deployment loop resistance. Does the resistance display within the specified range? | Approximately 1.6-6.4 ohms | Go to Step 7 | Go to Step 8 |
7 |
Did the DTC status change from NO DTCs? | -- | Go to Step 10 | Go to Step 13 |
Does the resistance display as specified? | Approximately 3 ohms | Go to Step 11 | Go to Step 9 | |
Did you find and correct the condition? | -- | Go to Step 13 | Go to Step 12 | |
10 | Locate and repair the intermittent short to ground in wiring harness. Refer to Testing for Intermittent Conditions and Poor Connections , Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 13 | -- |
11 | Replace the LH seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
12 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 13 | -- |
13 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
