Circuit Description
When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform tests to diagnose critical malfunctions within itself.
After passing these tests, ignition and deployment loop voltages are measured to ensure that they are within their respective normal voltage ranges. The SDM then proceeds with the resistance measurement test. Each inflator low terminal is grounded through a current sink, and each inflator current source is connected to each inflator high terminal to allow a known amount of current to flow.
By monitoring the voltage difference between each inflator high and low, the SDM calculates the combined resistance of the inflator module, the wiring harness, and the connector terminal contacts.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B0057 RF Pretensioner Deployment Loop Resistance Low
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
The resistance of passenger belt pretensioner deployment loop is lower than 1.4 ohms.
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
An intermittent condition likely to be caused by a short between the passenger belt pretensioner high and low circuits.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
|
Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Is there any visible damage to the SIR harness or connectors? | -- | Go to Step 3 | Go to Step 4 |
3 | Repair or replace the SIR wiring harness or connectors. Is the repair complete? | -- | Go to Step 8 | -- |
4 |
Is the resistance less than the specified value? | ∞ | Go to Step 3 | 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 |
Does the DTC reset? | -- | Go to Step 7 | System OK |
7 | Replace the passenger seat belt pretensioner. Did you complete the replacement? | -- | Go to Step 8 | -- |
8 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
