GM Service Manual Online
For 1990-2009 cars only

Integrity Check DERM

Circuit Description

When the inflatable restraint Diagnostic Energy Reserve Module (DERM) recognizes that the Ignition 1 voltage, applied to terminals A9 and A10, is in the normal operating voltage range, the AIR BAG warning lamp is flashed seven times to verify operation. At this time the DERM performs Turn On tests followed by Continuous Monitoring tests. When no malfunctions are detected, the DERM proceeds to the Initiator Assembly Resistance Test. When a malfunction is detected the DERM sets a current diagnostic trouble code and illuminates the AIR BAG warning lamp. The DERM will clear current diagnostic trouble codes and move them to a history file when the malfunction is no longer detected and/or the ignition switch is cycled, except for DTC B1051. DTC B1051 can only be cleared using a scan tool Clear Codes command.

Test Description

Refer to step numbers on the diagnostic table.

  1. Start with the SIR Diagnostic System Check for all diagnosis.

  2. This test confirms a current malfunction. If a History DTC set exists, reference the Diagnostic Aids for the appropriate DTC. Do not replace the DERM for a History DTC.

  3. This test checks for a malfunction introduced into the SIR system during the diagnostic process. A malfunctioning DERM is extremely unlikely to cause a new malfunction to occur during the diagnostic process.

  4. Replace the DERM only when all circuitry outside the DERM has been found to operate properly as indicated by the appropriate diagnostic table.

  5. The symptom or DTC is no longer occurring. The condition may be intermittent or was inadvertently repaired during diagnosis of the SIR system. Refer to Intermittents and Poor Connections in Section 8A4.

TABLE A - Integrity Check DERM

Step

Action

Value

Yes

No

1

Were you sent here from a Symptom Table or a Diagnostic Trouble Code Table?

--

Go to Step 2

Go to

SIR Diagnostic System Check

2

  1. Turn OFF the ignition switch.
  2. Reconnect all of the SIR system components.
  3. Ensure that the ignition switch has been off for at least two minutes.
  4. Note the AIR BAG warning lamp as the ignition switch is turned ON.

Does the AIR BAG warning lamp flash seven times and go off?

--

Go to Step 5

Go to Step 3

3

  1. Install a scan tool.
  2. Request the DTC display.

Is the same symptom on DTC occurring as when the SIR Diagnostic Check was performed?

--

Go to Step 4

Go to the indicated table

4

  1. Clear the SIR Diagnostic Trouble Codes.
  2. Turn OFF the ignition switch.
  3. Ensure that the ignition switch has been off for at least two minutes.
  4. Note the AIR BAG warning lamp as the ignition is turned ON.

Does the AIR BAG warning lamp flash seven times and then go off?

--

System OK

Go to Step 6

5

Clear the SIR Diagnostic Trouble Codes .

Have the SIR Diagnostic Trouble Codes been cleared?

--

Go to

SIR Diagnostic System Check

--

6

  1. Turn OFF the ignition switch.
  2. Replace the DERM. Refer to Inflatable Restraint Diagnostic Energy Reserve Module .

Has the DERM been replaced?

--

Go to

SIR Diagnostic System Check

--