For 1990-2009 cars
SIR Components
SIR Schematics
Handling ESD Sensitive Parts Notice
SIR Caution
SIR Caution
Handling ESD Sensitive Parts Notice

### Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Upon passing these tests IGNITION, 23VLR and the deployment loop voltages are measured to make sure they are within their respective normal voltage ranges. The SDM monitors the voltages at Driver Belt Low terminal 9 and Passenger Belt Low terminal 15 to detect shorts to B+ in the seat belt pretensioner deployment loops..

### Conditions for Setting the DTC

• | The voltage at Driver Belt Low terminal 9 is more than 4.5 volts for 500 milliseconds.

• | The voltage at Passenger Belt Low terminal 15 is less than 4.5 volts.

The CONTINUOUS MONITORING test checks for this DTC. This test occurs when IGNITION is within the normal operating voltage range.

### Action Taken When the DTC Sets

• | The SDM sets a Diagnostic Trouble Code.

• | The SDM turns ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

• | Current DTC

| The voltage at Driver Belt Low terminal 9 is less than 3.5 volts for 500 milliseconds.

• | History DTC

- | You issue a scan tool CLEAR CODES command.

- | Once 250 malfunction free ignition cycles have occurred.

### Diagnostic Aids

A short to B+ in the driver seat buckle side belt circuit can cause an intermittent condition. Inspect CKT 2118 and CKT 2119 carefully for cutting or chafing. Wiring pigtail damage requires replacement of the passenger seat buckle side belt. The diagnostic table directs the technician to note the entry value of LH PRETENS. SENSELO. Comparing the value of LH PRETENS. SENSELO can be helpful in determining if an intermittent condition exists.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections . When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair .

### Test Description

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

1. This test determines the driver side air bag low voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).

2. This test isolates the malfunction to one side of the driver seat buckle side belt yellow 2-way connector.

3. This test determines whether the malfunction is in CKT 2138.

4. This test determines whether the malfunction is in CKT 2137.

#### DTC B1044 LH Pretens Deploy. Loop Short to Voltage

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. Connect a scan tool to the DLC.
3. Turn the ignition switch to the RUN position.
4. Request the SIR data list display.
5. Read and record on the repair order the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Has the LH PRETENS. SENSELO been read and recorded on the repair order?

--

Go to Step 3

--

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint front side impact module (LH) and driver seat buckle side belt yellow 2-way connectors located under the driver seat.
3. Connect J 38715-A SIR Driver/Passenger Load Tool STEERING WHEEL and PASSENGER INFLATOR connectors to the yellow 2-way harness connectors.
4. Turn the ignition switch to the RUN position.
5. Using the scan tool, request the SIR data list display.
6. Read the driver seat belt pretensioner low voltage LH PRETENS. SENSELO.

Is LH PRETENS. SENSELO more than the specified value?

3.8 V

Go to Step 5

Go to Step 4

4 |

1. Turn the ignition switch to the OFF position.
2. Inspect the driver seat buckle side belt harness for damage and proper routing.
3. Replace the driver seat buckle side belt. Refer to Seat Buckle Side Belt Replacement in Seats and Carpet.

Are the repairs complete?

--

Go to Step 9

--

5 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM).
3. Disconnect the J 38715-A .
4. Turn the ignition switch to the RUN position.
5. Measure the voltage on the SDM harness connector from terminals 8 to 7 (ground).

Is the measured voltage less than the specified value?

1 V

Go to Step 7

Go to Step 6

6 | Repair a short to B+ condition in CKT 2118. Are the repairs complete? | -- | Go to Step 9 | --
7 | Measure the voltage on the SDM harness connector from terminals 9 to 7 (ground). Is the measured voltage less than the specified value? | 1 V | Go to Integrity Check | Go to Step 8
8 | Repair a short to B+ condition in CKT 2119. Are the repairs complete? | -- | Go to Step 9 | --
9 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to Step 10 | --
10 | Clear all the SIR DTCs. Have all the DTCs been cleared? | Go to SIR Diagnostic System Check