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

### Circuit Description

When you turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests in order to diagnose critical malfunctions. Upon passing these tests, the system measures IGNITION 1 voltage, the 23-volt loop reserve, and deployment loop voltages in order to verify normal voltage ranges. The SDM monitors the voltages at the DRIVER SIDE LOW terminal 10 and at the Passenger Side Low terminal 3 in order to detect shorts to B+ in the inflator module circuits. The service wait time is 10 minutes. Refer to Disabling the SIR System .

### Conditions for Setting the DTC

• | The voltage at Driver Side Low terminal 10 is less than 3.5 volts.

• | The voltage at the Passenger Side Low terminal 3 is more than 3.5 volts for 500 milliseconds.

The Continuous Monitoring test checks for this DTC. This test occurs if IGNITION 1 is within the normal operating range.

### Action Taken When the DTC Sets

• | The SDM sets DTC B1019 and DTC B1071.

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

### Conditions for Clearing the DTC

DTC B1019 is a latched code. You cannot clear a latched code. Before you replace the SDM, repair the malfunction that sets the DTC.

### Diagnostic Aids

A short-to-B+ in the circuit of the inflatable restraint IP module can cause an intermittent condition. DTC B1071 would occur with DTC B1019. Inspect the YEL/RED wire and the YEL wire carefully for broken wires or for chafed wires. Wiring pigtail damage requires replacement of the inflatable restraint IP module. Careful inspection of the circuits and of the components on the DTC B1019 Table prevents damage to the replacement SDM.

The diagnostic table directs the technician to note the entry value of PASSENGER SENSELO. Comparing the value of the PASSENGER SENSELO can help determine if an intermittent condition exists.

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

### Test Description

Numbers below refer to step numbers on the diagnostic table.

1. This test determines the Passenger Side Low voltage measured by the inflatable restraint Sensing and Diagnostic Module (SDM).

2. This test isolates the malfunction to one side of the inflatable restraint IP module yellow connector located behind the IP compartment.

3. This test determines whether the malfunction is in the YEL/RED wire.

4. This test determines whether the malfunction is in the YEL wire.

#### DTC B1019 Passenger Deploy. Loop Short To Voltage

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Notice: When DTC B1019 is set, it is necessary to replace the inflatable restraint Sensing and Diagnostic Module (SDM). Setting DTC B1019 also causes DTC B1071 to set. When a scan tool clear codes command is issued and the malfunction is no longer present, DTC B1019 and DTC B1071 will remain current. Ensure that the short to B+ condition is repaired prior to installing a replacement SDM in order to avoid damaging the SDM.
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 the Passenger Side Low voltage PASSENGER SENSELO. Record onto the repair order.

Did you read the PASSENGER SENSELO? Did you record PASSENGER SENSELO on the repair order?

--

Go to Step 3

--

3 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the inflatable restraint (SIR) steering wheel and inflatable restraint IP modules yellow connectors. These are located under the steering wheel side cap and behind the IP compartment.
3. Connect the J 38715-A to the inflatable restraint IP module harness connectors.
4. Turn the ignition switch to the ON position.
5. Using the scan tool, request the SIR data list display. Read the PASSENGER SIDE LOW voltage PASSENGER SENSELO.

Is the PASSENGER SENSELO more than the specified value?

3.5 V

Go to Step 5

Go to Step 4

4 |

1. Turn the ignition switch to the LOCK position.
2. Inspect the inflatable restraint IP module pigtail for damage. Verify that the pigtail and the nearby wiring are routed correctly.
3. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you replace the inflatable restraint IP module?

--

Go to Step 9

--

5 |

1. Turn the ignition switch to the LOCK position.
2. Disconnect the inflatable restraint Sensing Diagnostic Module (SDM).
3. Disconnect the J 38715-A .
4. Turn the ignition switch to the ON position.
5. Measure the voltage on the SDM harness connector from terminal 4 to terminal 6 (ground).

Is the measured voltage less than the specified value?

1 V

Go to Step 7

Go to Step 6

6 |

1. Turn the ignition switch to the LOCK position.
2. Repair a short to B+ condition in the YEL/RED wire.

Is the circuit repair complete?

--

Go to Step 9

--

7 | Measure the voltage on the SDM harness connector from terminal 3 to terminal 6 (ground). Is the measured voltage less than the specified value? | 1 V | Go to Sensing and Diagnostic Module Integrity Check | Go to Step 8
8 |

1. Turn the ignition switch to the LOCK position.
2. Repair a short to B+ condition in the YEL wire.

Is the circuit repair complete?

--

Go to Step 9

--

9 |

1. Reconnect all the SIR system components, make sure all the components are properly mounted.
2. Turn the ignition switch to RUN.
3. Verify that the PASSENGER SENSELO is less than the specified value.
4. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you reconnect all the SIR components?

Did you properly mount all the SIR components?

3.5 V

Go to Step 10

--

10 | Clear the SIR diagnostic trouble codes. Have the SIR diagnostic trouble codes been cleared? | -- | Go to SIR Diagnostic System Check | --