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 DTC1015.

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 poor connection at the passenger inflator module harness connector terminals A or B, SDM terminals A1 or A4, or a poor wire to terminal connection to circuits 1403 or 1404. This test for this diagnostic trouble code is only run while the 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. This test determines whether the malfunction is in the passenger inflator module circuitry or in the SDM wiring harness circuitry.

  2. This test checks whether the malfunction is due to high resistance in Circuit 1403.

  3. This test checks whether the malfunction is due to high resistance in Circuit 1404.

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 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. Check for proper connection to passenger inflator module at terminals A and B.
  4. If not ok, repair and go to Step 8
  5. If ok, then connect SA 9409Z-A SIR driver/passenger load tool to driver and passenger inflator module harness connectors.
  6. Turn ON the ignition.

Is DTC B1015 current?

Go to Step 3

Go to Step 4

3

  1. Turn OFF the ignition.
  2. Disconnect SIR driver passenger load tool.
  3. Check for proper connection to SDM at terminals A1 and A4.
  4. If not ok, then repair and go to Step 8
  5. If ok measure resistance from SDM harness connector terminal A1 to passenger inflator module harness connector terminal B.

Is resistance one ohm or less?

Go to Step 5

Go to Step 6

4

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

Go to Step 8

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5

Measure resistance from SDM harness connector terminal A4 to passenger inflator module harness connector terminal A.

Is resistance one ohm or less?

Go to Chart A

Go to Step 7

6

Repair high resistance or open in circuit 1403.

Go to Step 8

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7

Repair high resistance or open in circuit 1404.

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 codes.
  3. Repeat SIR Diagnostic System Check.

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