For 1990-2009 cars
SIR Components
Power, Ground, Serial Data, Indicator and Front Inflatable Restraint Modules
SIR Caution
Handling ESD Sensitive Parts Notice

### Circuit Description

When you first turn ON the ignition, the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) performs tests to diagnose critical malfunctions within itself. Then, the SDM proceeds with the RESISTANCE MEASUREMENT test to measure the deployment loop resistances to ensure they are within their respective normal resistance ranges. Upon passing these tests, the energy reserve is charged and the firing transistors are tested. The SDM then goes into CONTINUOUS MONITORING mode.

### Conditions for Running the DTC

When the ignition voltage is within the normal operating voltage range, the SDM monitors all deployment loops in order to detect a leakage current to ground in the passenger seat belt pretensioner deployment loop.

### Conditions for Setting the DTC

The measured leakage current to ground is above the specified value in the passenger seat belt pretensioner deployment loop.

### Action Taken When the DTC Sets

The SDM turns ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

• | You can issue a CLEAR CODES command.

• | A history DTC will clear once 255 malfunction free cycles have occurred.

### Diagnostic Aids

A short to ground in the passenger seat belt pretensioner deployment loop can cause an intermittent condition. Inspect the passenger belt high and passenger belt low circuits carefully for cutting or chafing. Wiring pigtail damage requires replacement of the passenger seat belt pretensioner.

### Test Description

The numbers below refer to step numbers on the diagnostic table.

1. This step checks the passenger seat belt pretensioner 2-way connector.

2. This step checks to see if there is a short to ground in the passenger belt high circuit.

3. This step determines if there is a short to ground in the passenger belt low circuit or if there is a malfunctioning SDM.

4. This step clears all SIR DTCs.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform A Diagnostic System Check - SIR? | -- | Go to Step 2 | Go to Diagnostic System Check - SIR
2 |

1. Turn OFF the ignition.
2. Remove the ignition key.
3. Disconnect the passenger seat belt pretensioner 2-way wiring harness connector. Refer to Seat Belt Buckle Pretensioner Replacement - Right Side .
4. Inspect the male and female sides of the inline connector for the following conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems:

• | Corrosion

• | Damaged terminals

• | Poor connections/terminal tension

Does either the male or female sides of the inline connector exhibit signs of corrosion, terminal damage, or poor connections?

--

Go to Step 3

Go to Step 4

3 |

1. If the female side of the inline connector is damaged, the passenger seat belt pretensioner must be replaced.
2. If the male side of the inline connector is damaged, replace the male side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the replacement?

--

Go to Step 12

--

4 |

1. Reconnect the passenger seat belt pretensioner 2-way connector.
2. Verify that the connector position assurance (CPA) is properly installed.
3. Turn ON the ignition, with the engine OFF.
4. Use the scan tool to request the SIR DTC display.

Does the scan tool indicate that this DTC is current?

--

Go to Step 5

Go to Diagnostic Aids

5 |

1. Turn OFF the ignition.
2. Remove the ignition key.
3. Use the J 38715-55 adaptor to connect the J 38715-A SIR Driver/Passenger Load Tool PASSENGER INFLATOR connector to the passenger seat belt pretensioner 2-way wiring harness connector.
4. Turn ON the ignition, with the engine OFF.
5. Use the scan tool to request the SIR DTC display.

Does the scan tool indicate that this DTC is current?

--

Go to Step 7

Go to Step 6

6 |

1. Turn OFF the ignition.
2. Remove the ignition key.
3. Replace the passenger seat belt pretensioner. Refer to Seat Belt Buckle Pretensioner Replacement - Right Side .

Did you complete the replacement?

--

Go to Step 12

--

7 |

1. Turn OFF the ignition.
2. Remove the ignition key.
3. Remove the J 38715-A .
4. Disconnect the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .
5. Install the J 42113 SIR Shorting Bar Tool into the SDM wiring harness connector above the passenger belt high and the passenger belt low circuits.
6. Use the J 39200 Digital Multimeter (DMM) to measure the resistance between the passenger belt high circuit and a known good ground.

Does the resistance measure less than the specified value?

OL

Go to Step 8

Go to Step 9

8 | Locate and repair the short to ground in the passenger belt high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | --
9 | Use the DMM to measure the resistance between the driver belt low circuit and a known good ground. Does the resistance measure less than the specified value? | OL | Go to Step 10 | Go to Step 11
10 | Locate and repair the short to ground in the passenger belt low circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 12 | --
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | --
12 |

1. Reconnect all SIR components.
2. Verify that all connectors and components are properly mounted.
3. Turn On the ignition, with the engine OFF.
4. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to Diagnostic System Check - SIR

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