GM Service Manual Online
For 1990-2009 cars only

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. Upon 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. right side belt pretensioner low terminal B3 is grounded through a current sink, and the right side belt pretensioner current source is connected to the right side belt pretensioner high terminal to allow a known amount of current to flow. By monitoring the voltage difference between the right side belt pretensioner high and right side belt pretensioner low terminals, the SDM calculates the combined resistance of the right side belt pretensioner inflator module, harness wiring, and connector terminal contacts.

Conditions for Setting the DTC

  1. Resistance of the right side belt pretensioner deployment loop is less than 1.2 ohms for 500 milliseconds.
  2. Ignition voltage is within normal operation range.

Action Taken When the DTC Sets

The SDM will turn ON the AIRBAG indicator and set a diagnostic trouble code DTC 57.

Conditions for Clearing the DTC

  1. Resistance of the right side belt pretensioner deployment loop is higher than or equal to 1.2 ohms for 500 milliseconds.
  2. Turn OFF the ignition switch.
  3. The scan tool CLEAR CODES command is received.

Diagnostic Aids

An intermittent condition is likely to be caused by a short between the right side belt pretensioner high and low circuits, a short between the right side belt pretensioner high circuit and the left side belt high circuit, a short on C221 or a short between the right side belt pretensioner high circuit and the left side belt low circuit. The problem could also be a malfunctioning shorting bar in the right side belt pretensioner airbag connector, which would require replacement of the right side belt pretensioner airbag module. The test for this DTC is run only while the AIRBAG indicator is performing the turn-on test. When a scan tool CLEAR CODES command is issued while the malfunction is still present, the DTC will not reappear until the next ignition cycle.

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.

Step

Action

Values

Yes

No

1

Perform the Diagnostic System Check - SIR.

Is the Diagnostic System Check - SIR complete?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition and remove the key.
  2. Connect the scan tool to the Data Link Connector (DLC).
  3. Turn ON the ignition.

Is the DTC 64 also displayed?

--

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition and remove the key.
  2. Disconnect the yellow airbag connectors at the steering column, passenger airbag and connector C221.
  3. Repair the short between the right side belt pretensioner high circuit and the left side belt pretensioner high circuit.
  4. Make sure all SIR components are reconnected and all components are properly mounted.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

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4

  1. Turn OFF the ignition and remove the key.
  2. Disconnect the connector C221 and the right side belt pretensioner connector.
  3. Measure the resistance between terminal A and B of the right side belt pretensioner.

Refer to Diagnostic Illustration 17 in SIR Diagnostic Illustrations .

Is the resistance equal to the specified value?

Go to Step 5

Go to Step 7

5

  1. Replace the sensing and diagnostic module (SDM). The arrow must be pointing to the front of the vehicle.
  2. Connect all the wiring connectors. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Clear all trouble codes with a scanner.

Did you complete the repair?

--

System OK

Go to Step 6

6

Replace the right side belt pretensioner.

Did you complete the repair?

--

System OK

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7

Repair the short between the right side belt pretensioner high circuit and the right side belt pretensioner low circuit or replace the wiring harness.

Did you complete the repair?

--

Go to Diagnostic System Check - SIR

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