GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Prizm 🢒 Restraints 🢒 SIR 🢒 DTC 72 LH Pretens Deploy. Loop Short to Voltage

Object Number: 238653 Size: SF
SIR Components
SIR Schematics
SIR Caution
SIR Caution
Handling ESD Sensitive Parts Notice

Circuit Description

When you first turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM monitors the voltages at LH PRETENSIONER LOW terminal 1 to detect shorts-to-B+ in the seat belt pretensioner circuits.

Conditions for Setting the DTC

The SDM detects a short to battery voltage in the LH seat belt pretensioner deployment loop.

Action Taken When the DTC Sets
    • The SDM sets a Diagnostic Trouble Code.
    • The SDM flashes the AIR BAG warning lamp.

Conditions for Clearing the DTC

All DTCs are cleared with each ignition cycle.

Diagnostic Aids

A short to B+ in the seat belt pretensioner circuit can cause an intermittent condition. Inspect the YEL/BLK and YEL wires leading to the seat belt pretensioner carefully for cut or chafed wires.

Test Description

  1. This test checks for a short to voltage in the LH pretensioner high circuit.

    2.

  2. This test checks for a short to voltage in the LH pretensioner low circuit.

    3.

  3. This test determines if the malfunction is caused by the SDM.

    4.

  4. This test determines if the malfunction is caused by the LH pretensioner.

Step

Action

Value(s)

Yes

No

1

Was the SIR Diagnostic System Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM).
  3. Disconnect the LH seat belt pretensioner.
  4. Turn the ignition switch to the ON position.
  5. Measure the voltage at the pretensioner harness connector between terminal 1 and ground.

Is the voltage measured greater than the specified value?

0 V

Go to Step 8

Go to Step 3

3

Measure the voltage at the pretensioner harness connector between terminal 2 and ground.

Is the voltage measured greater than the specified value?

0 V

Go to Step 9

Go to Step 4

4

  1. Turn the ignition switch to the OFF position.
  2. Connect the SDM.
  3. Connect a jumper wire between terminals 1 and 2 of the pretensioner harness connector.
  4. Turn the ignition switch to the ACC or ON position and wait 20 seconds.
  5. Clear SIR DTCs.
  6. Turn the ignition switch to the ACC or ON position and wait 20 seconds.
  7. Check for SIR DTCs.

Is DTC 72 present?

--

Go to Step 6

Go to Step 5

5

  1. Turn the ignition switch to the OFF position.
  2. Connect the pretensioner connector.
  3. Turn the ignition switch to ACC or ON and wait 20 seconds.
  4. Clear SIR DTCs.
  5. Turn the ignition switch to the ACC or ON position and wait 20 seconds.
  6. Check for SIR DTCs.

Is DTC 72 present?

--

Go to Step 7

Go to Step 10

6

Replace the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Are all the repairs complete?

--

Go to Step 11

--

7

Replace the driver seat belt. Refer to Seat Belt Retractor Replacement - Left Front in Seat Belts.

Are all the repairs complete?

--

Go to Step 11

--

8

Repair a short to voltage in the YEL/BLK wire between the pretensioner and the SDM. Refer to Wiring Repair in this section.

Are all the repairs complete?

--

Go to Step 11

--

9

Repair a short to voltage in the YEL wire between the pretensioner and the SDM. Refer to Wiring Repair in this section.

Are all the repairs complete?

--

Go to Step 11

--

10

An intermittent exists in the driver seat belt deployment loop. Refer to Diagnostic Aids.

Are all the repairs complete?

--

Go to Step 11

--

11

Reconnect all SIR components. Make sure all components are properly mounted.

Have all the SIR components been reconnected and properly mounted?

--

Go to SIR Diagnostic System Check

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