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

### Circuit Description

When you first turn the ignition switch to the ON position, the inflatable Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. Next the SDM measures IGNITION 1 and the deployment loop voltages to make sure they are within their respective normal voltage ranges. Then the SDM proceeds with the RESISTANCE MEASUREMENT test. During one portion of the RESISTANCE MEASUREMENT test, the SDM does the following:

• | Grounds the DRIVER SIDE LOW terminal 10 through an internal current sink.

• | Connects the DRIVER SIDE HIGH terminal 9 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.

| Measure the voltage difference between the DRIVER SIDE HIGH and DRIVER SIDE LOW.

• | Calculates the resistance of the driver deployment loop using the measured voltage.

### Conditions for Setting the DTC

• | The driver and passenger deployment loops are not open.

• | The driver and passenger deployment loops are not shorted to voltage.

• | The driver deployment loop is not shorted to ground.

• | The driver deployment loop resistance is less than 1.8 ohms. The driver deployment loop consists of the following components:

- | Inflatable restraint steering wheel module.

- | Inflatable restraint steering wheel module coil.

- | Harness wiring of the GRN/RED wire.

- | Harness wiring of the GRN wire.

- | Connector terminal contact.

The RESISTANCE MEASUREMENT test checks for this malfunction. This test only occurs once each ignition cycle when IGNITION 1 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

• | Clear the Current DTC when the resistance of the driver deployment loop is more than 1.8 ohms and the ignition switch is cycled.

• | Clear the History DTC under the following conditions:

- | You issue a scan tool CLEAR CODES command.

- | 250 malfunction free ignition cycles have occurred.

When you issue a scan tool CLEAR CODES command and the malfunction is still present, the DTC will not reappear until the next ignition cycle

### Diagnostic Aids

the following can cause an intermittent condition:

• | A short circuit between the GRN/RED wire and the GRN wire.

• | A short circuit between the GRN/RED wire and the YEL/RED wire.

• | A short circuit between the GRN/RED wire and the YEL wire.

• | A malfunctioning shorting bar on the inflatable restraint steering wheel module connector.

• | A malfunctioning shorting bar on the inflatable restraint steering wheel module coil steering column connector.

The diagnostic table directs the technician to note the entry value of DRIVER RESISTANCE. Comparing the value of DRIVER RESISTANCE 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 in this section.

### Test Description

Numbers below refer to step numbers on the diagnostic table.

1. This test determines the deployment loop resistance measured by the inflatable restraint Sensing and Diagnostic Module (SDM).

2. This test isolates the malfunction to one side of the yellow 2-way connector on the inflatable restraint steering wheel module coil. This connector is located near the base of the steering column.

3. This test determines whether the malfunction is in the inflatable restraint steering wheel module coil or the inflatable restraint steering wheel module.

4. This test checks for a short from the GRN/RED wire to the GRN wire.

5. This test checks for a short from the GRN/RED wire to the YEL wire.

#### DTC B1022 Driver Deployment Loop Resistance Low

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 LOCK position.
2. Connect a scan tool to the data link connector. Follow the directions in the instruction manual of the scan tool.
3. Turn the ignition switch to the ON position.
4. Request the SIR data list display.
5. Read and record on the repair order the driver deployment loop resistance DRIVER RESISTANCE.
6. Request the SIR diagnostic trouble code display.

Is DTC B1016 also current?

--

Go to Step 3

Go to Step 4

3 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the yellow connectors on the inflatable restraint steering wheel module and on the inflatable restraint IP module. These connectors are located under the steering wheel side cap and behind the IP compartment.
3. Repair the short from the GRN/RED wire to the YEL/RED wire.

Is the circuit repair complete?

--

Go to Step 14

--

4 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the yellow 2-way connector on the inflatable restraint steering wheel module. This connector is located near the base of the steering column.
3. Reconnect the yellow 2-way connector on the inflatable restraint steering wheel module.
4. Make sure that the connector is properly seated and that the CPA is installed properly.
5. Turn the ignition switch to the ON position.
6. Using the scan tool, request the SIR data list display. Read the driver deployment loop resistance DRIVER RESISTANCE.

Is the DRIVER RESISTANCE less than the specified value?

1.8ohms

Go to Step 6

Go to Step 5

5 |

1. Turn the ignition switch to the LOCK position
2. Replace the yellow 2-way harness connector at the base of the steering wheel. Refer to SIR Connector (Plastic Body and Terminal Metal Pin) Repair portion of Wiring Repair .

Have you replaced the yellow 2-way harness connector?

--

Go to Step 14

--

6 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the yellow 2-way connectors on the inflatable restraint steering wheel module and the inflatable restraint IP module. These connectors are located near the base of the steering column and behind the IP compartment.
3. Connect the J 38715-A SIR Driver/Passenger Load Tool to the inflatable restraint steering wheel module harness connector and to the inflatable restraint IP module harness connector.
4. Turn the ignition switch to the ON position.
5. Using the scan tool, request the SIR data list display and read the driver deployment loop resistance DRIVER RESISTANCE.

Is DRIVER RESISTANCE less than the specified value?

1.8ohms

Go to Step 10

Go to Step 7

7 |

1. Turn the ignition switch to the LOCK position.
2. Remove the inflatable restraint steering wheel module from the steering wheel. Refer to Inflatable Restraint Steering Wheel Module Replacement .
3. Reconnect the 2-way connector at the base of the steering column.
4. Connect the J 38715-A to the inflator module connector on the steering column.
5. Turn the ignition switch to the ON position.
6. Using the scan tool, request the SIR data list display, and read the driver deployment loop resistance DRIVER RESISTANCE.

Is DRIVER RESISTANCE less than the specified value?

1.8ohms

Go to Step 9

Go to Step 8

8 |

1. Turn the ignition switch to the LOCK position.
2. Replace the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Have you replaced the inflatable restraint steering wheel module?

--

Go to Step 14

--

9 |

1. Turn the ignition switch to the LOCK position.
2. Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Have you replaced the inflatable restraint steering wheel module coil?

--

Go to Step 14

--

10 |

1. Turn the ignition switch to the LOCK position.
2. Disable the inflatable restraint Sensing and Diagnostic Module (SDM).
3. Disconnect the J 38715-A .
4. Measure the resistance from the SDM harness connector terminal 9 to terminal 10.

Is the resistance reading less than the specified value?

OL

Go to Step 11

Go to Step 12

11 |

1. Turn the ignition switch to the LOCK position.
2. Repair the short from the GRN/RED wire to the GRN wire.

Is the repair complete?

--

Go to Step 14

--

12 | Measure the resistance from the SDM harness connector terminal 9 to terminal 3. Is the resistance reading less than the specified value? | OL | Go to Step 13 | Go to AIR BAG Warning Lamp Comes On Steady
13 | Repair the short from the GRN/RED wire to the YEL wire. Is the repair complete? | -- | Go to Step 14 | --
14 | Reconnect and mount all the SIR system components. Have all the SIR components been reconnected and properly mounted? | -- | Go to Step 15 | --
15 | Clear the SIR diagnostic trouble codes. Have you cleared all the SIR diagnostic trouble codes? | -- | Go to SIR Diagnostic System Check | --