GM Service Manual Online
For 1990-2009 cars only

Object Number: 1207177  Size: MF

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 then proceeds with the "Current Source Diagnostic""Passenger Side LO" terminal A4 is grounded through a resistor and the passenger current source connected to "Passenger Side HI" terminal A1 allows a known amount of current to flow. By monitoring the voltage difference between "Passenger Side HI" and the "Passenger Side LO" the SDM calculates the combined resistance of the passenger inflator module, harness wiring Circuits 1403 and 1404 and connector terminal contact.

DTC Will Set When

The combined resistance of the passenger inflator module harness wiring circuits 1403 and 1404 and connector terminal contact is greater than 3.6 ohms. This test is run once each ignition cycle during the "Current Source Diagnostics" when:

  1. No "higher priority faults" are detected during "Turn On".
  2. No "higher priority faults" are detected during "Continuous Monitoring".
  3. "Ignition 1" voltage is above a specified value.

Action Taken

SDM turns ON the AIR BAG telltale lamp and sets DTCB1015.

DTC Will Clear When

The malfunction is no longer occurring and the ignition switch is turned OFF, or a Scan Tool "Clear Codes" command is issued.

Diagnostic Aids

An intermittent condition is likely to be caused by a short between circuit 1404, and circuit 347, 348 or 1403, or a malfunction shorting bar on the passenger inflator module which would require replacement of the module. The test for this diagnostic trouble code is only run while AIR BAG telltale lamp is performing the bulb check, unless DTC B1017 or B1026 is detected. When a Scan tool "Clear Codes" command is issued and the malfunction is still present, the DTC will not reappear until the next ignition cycle.

When measurements are requested in this chart use SA 91114NEDVM 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. DTC B1016 and B1022 will set simultaneously when the "Driver Side H1" circuit is shortened to the "Passenger" Side H1 circuit due to parallel current paths.

  2. This test determines whether the malfunction is in the passenger inflator module circuitry or in the SDM wiring harness circuitry.

  3. This test checks for a short from the "Passenger Side HI" circuit to the "Passenger Side LO" circuit.

  4. This test checks for a short from the "Passenger Side HI" circuit to the " Driver Side LO" circuit.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - SIR?

Go to Step 2

Go to SIR Diagnostic System Check

2

Is DTC B1022 current?

Go to Step 4

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect driver and passenger inflator modules, yellow two-way connectors located at the base of the steering column and under the I/P top cover.
  3. Connect SA9409Z-A SIR driver/passenger load tool to driver and passenger inflator module harness connectors.
  4. Turn ON ignition.

Is DTC B1016 current?

Go to Step 5

Go to Step 6

4

  1. Turn OFF the ignition.
  2. Disconnect driver and passenger inflator modules, yellow two-way connectors located at the base of the steering column and under the I/P top cover.
  3. Repair short from circuit 347 to circuit 1403.

Go to Step 10

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5

  1. Turn OFF ignition.
  2. Disconnect SDM.
  3. Measure resistance on the SDM harness connector from terminal A1 to terminal A4.

Does DVM display OL (Infinite)?

Go to Step 7

Go to Step 8

6

  1. Turn OFF ignition.
  2. Replace passenger inflator module.

Go to Step 10

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7

Measure resistance on SDM harness connector from terminal A3 to terminal A1.

Does DVM display OL (Infinite)?

Go to Chart A

Go to Step 9

8

Repair short from circuit 1403 to circuit 1404.

Go to step 10

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9

Repair short from circuit 1403 to circuit 348.

Go to Step 9

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10

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

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