For 1990-2009 cars

### Circuit Description

When the ignition switch is first turned ON, the SDM will perform tests to diagnose critical malfunctions within itself. Upon passing these tests "Ignition 1", VLR, and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. The SDM monitors the voltage at "Driver Side LO" terminal A3 and "Passenger Side LO" terminal A4 to detect shorts in B+ or ignition in the inflator module circuits.

### DTC Will Set When

The VLR power supply in the SDM is in its normal operating range and neither of the two inflator modules is not open. Then, if the voltage measured at "Driver Side LO" is greater than 5 volts and the voltage measured at "Passenger Side LO" is greater than or equal to 3 volts for 500 milliseconds during "Continuous Monitoring" or "Current Source Diagnostic," DTC B1019 will set. DTC B1019 will take precedence over DTC's B1015,B1016,B1021, B1022 and B1024.

### Action Taken

SDM turns ON the AIR BAG telltale lamp and sets, DTC B1019 and also B1071. DTC B1019 will take precedence over DTC's B1015, B1016, B1021, B1022 and B1024.

### DTC Will Clear When

The voltage measured at "Passenger Side LO" is less than 4 volts for 500 milliseconds during "Continuous Monitoring". Or, the malfunction no longer exists and the ignition switch is turned OFF.

### Diagnostic Aids

An intermittent condition is likely to be caused by a short to B+ or ignition in the passenger inflator module circuits. Inspect circuits 1403 and 1404 carefully for cutting or chafing. If the wiring of the passenger inflator module is damaged, the module must be replaced.

The test for this diagnostic trouble code is run during "Continuous Monitoring" and "Current Source Diagnostics," unless DTC B1017 or B1026 is detected.

When measurements are requested in this chart use SA 91114NE DVM with correct terminal adapter from SA 9206Z. When a check for proper connection is requested refer to Intermittent and Poor Connections. When a wire connector or terminal repair is requested, use the proper repair parts and refer to Wiring Repairs .

### Test Description

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

1. This test determines whether the malfunction is occurring in the passenger inflator module, or the circuitry.

2. This test checks for a short from "Passenger Side HI" to B+ or ignition.

3. This test checks for a short from "Passenger Side LO" B+ or ignition or a SDM integrity problem.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - SIR? | Go to Step 2 | Go to SIR Diagnostic System Check
2 |

1. Turn OFF ignition.
2. Disconnect passenger inflator module, yellow two-way connectors located under the I/P top cover. Leave driver inflator module connected.
3. Connect SIR driver/passenger load tool SA9409Z-A to passenger inflator module harness connector.
4. Turn ON ignition.

Go to Step 7

Go to Step 4

Go to Step 3

3 |

1. Turn OFF ignition.
2. Remove and inspect passenger inflator module and connecting wires for damage. Determine and repair cause of damage.
3. Replace passenger inflator module. Refer to Passenger Inflator Module.

Does DVM display OL (Infinite)?

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4 |

1. Turn OFF ignition.
2. Disconnect SIR driver/passenger load tool.
3. Disconnect SDM.
4. Measure voltage on SDM harness connector from terminal A1 to terminal A6 (ground).

Is voltage 1 volt or less?

Go to Step 5

Go to Step 6

5 | Measure voltage on SDM harness connector from terminal A4 to terminal A6 (ground). Is voltage 1 volt or less? | Go to Chart A | Go to Step 7
6 |

1. Turn OFF ignition.
2. Repair short from circuit 1403 to B+, or ignition circuit 1139.

Go to Step 7

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7 |

1. Turn OFF ignition.
2. Repair short from circuit 1404 to B+, or ignition circuit 1139.

Go to Step 8

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8 |

1. Reconnect all SIR system components. Ensure all components are properly mounted.
2. Clear SIR diagnostic trouble code.
3. Repeat SIR Diagnostic System Check.

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