GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 Catera 🢒 DTC 🢒 DTC 76 Driver Side Air Bag Short to Voltage

Object Number: 255419 Size: SF
SIR Components
SIR Schematics
Handling ESD Sensitive Parts Notice
SIR Caution
SIR Caution
Handling ESD Sensitive Parts Notice

Circuit Description

The inflatable restraint Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM) performs tests to diagnose critical malfunctions within itself when the ignition switch is turned ON. The SDM monitors the six firing loops to detect leakage currents to ground in the frontal and side air bag inflator module and seat belt pretensioner circuits. The deployment loop resistances are measured to ensure they are within their respective normal resistance ranges. Upon passing these tests, and if the energy reserve is charged up, the firing transistors are tested. The SDM service wait time is 1 minute. Refer to On-Vehicle Service for enable/disable procedures.

Conditions for Setting the DTC
  1. Neither of the two side air bag circuits is open.
  2. The ignition is within normal operating voltage range.
  3. The measured leakage currents to system voltage in the driver side air bag deployment loop are above a specified value.

DTC 76 will set once these conditions are met. This test is run during the SDM Turn-ON tests.

Action Taken When the DTC Sets
    • The SDM sets a Diagnostic Trouble Code.
    • The SDM turns ON the AIR BAG warning lamp.

Conditions for Clearing the DTC

Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool.

Diagnostic Aids

A short circuit to a voltage source in the inflatable restraint driver seat module circuit or a short circuit between the communication signal line of the LH or RH inflatable restraint Side Impact Sensor can set this DTC. Inspect CKTs XB100 and AB11 carefully for cutting and/or chafing. A careful inspection of the circuits and components indicated on the DTC 76 Table is essential to make sure that the replacement SDM will not be damaged.

    •  If DTC DTC 73 and DTC 76 are set, inspect CKTs AB11 and B41 carefully for cutting and/or chafing.
    •  If DTC 76 and DTC 83 are set, inspect CKTs AB11 and M44 carefully for cutting and/or chafing.

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

Test Description

The following numbers refer to the step numbers on the diagnostic table:

  1. This test isolates the malfunction to one side of the inflatable restraint driver seat module yellow integral harness.

    2.

  2. This test isolates the malfunction to one side of the inflatable restraint driver seat harness located under the LH front seat track cover.

    3.

  3. This test determines whether the malfunction is in CKT AB11.

    4.

  4. This test determines whether the malfunction is in CKT XB100.

DTC 76 Driver Side Air Bag Deployment Loop Short to Voltage

Step

Action

Value(s)

Yes

No

1

Was the SIR Diagnostic Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn the ignition switch OFF.
  2. Wait 1 minute until the capacitors in the Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM) have discharged.
  3. Remove the driver seat back cover. Refer to Seat Back Replacement - Front in Seats.
  4. Disconnect the inflatable restraint driver seat module 2-way integral connector.
  5. Using the J 38715-30 adapter, connect the J 38715-A to the inflatable restraint driver seat module 2-way integral connector.
  6. Turn the ignition switch to the ON position.
  7. Use the scan to request the SIR Diagnostic Trouble Codes (DTCs).

Is a current DTC 76 displayed?

--

Go to Step 4

Go to Step 3

3

Replace the inflatable restraint driver seat module. Refer to Inflatable Restraint Seat Module Replacement - Driver .

Is the replacement complete?

--

Go to Step 15

--

4

  1. Turn the ignition switch to the OFF position.
  2. Wait 1 minute until the capacitors in the Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM) have discharged.
  3. Disconnect the inflatable restraint driver seat module yellow 2-way harness connector C208 located under the LH seat track cover.
  4. Using the J 38715-55 adapter, connect 38715-A to the inflatable restraint driver seat module 2-way integral connector.
  5. Turn the ignition switch to the ON position.
  6. Use the scan to request the SIR Diagnostic Trouble Codes (DTCs).

Is a current DTC 76 displayed?

--

Go to Step 6

Go to Step 5

5

Replace the inflatable restraint driver seat harness.

Is the replacement complete?

--

Go to Step 15

--

6
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the J 38715-A.
  3. Disconnect the SDM. Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .
  4. Check for proper connection at terminal 10 and terminal 11 on the SDM harness connector.

Is the harness connector damaged or corroded?

--

Go to Step 7

Go to Step 9

7

Replace the IP harness.

Are the repairs complete?

--

Go to Step 8

--

8

Check for proper connection at terminals 10 and 11 on the SDM.

Are the terminals damaged or corroded?

--

Go to Step 10

Go to Step 15

9

Check for proper connection at terminals 10 and 11 on the SDM.

Are the terminals damaged or corroded?

--

Go to Step 10

Go to Step 11

10

Replace the inflatable restraint Sensing and Diagnostic and Seat Belt Pretensioner Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .

Are the repairs complete?

--

Go to Step 15

--

11

  1. Insert J 42113 Shorting Bar Tool into the SDM harness connector terminal above terminals 10 and 11 on the SDM harness connect
  2. Turn the ignition switch to the ON position.
  3. Use the J 39200 to measure the voltage on the SDM harness connector from terminal 11 to terminal 7 (ground).

Is the voltage reading less than the specified value?

1 V

Go to Step 13

Go to Step 12

12
  1. Turn the ignition switch OFF.
  2. Repair the short to voltage condition in CKT AB11.

Is the repair complete?

--

Go to Step 15

--

13

Use the J 39200 to measure the voltage on the SDM harness connector from terminal 10 to terminal 7 (ground).

Is the voltage reading less than the specified value?

1 V

Go to Integrity Check

Go to Step 14

14
  1. Turn the ignition switch OFF.
  2. Repair the short to voltage condition in CKT XB100.

Is the repair complete?

--

Go to Step 15

--

15

Reconnect all of the SIR components, make sure all the components are properly mounted.

Have all the SIR components been reconnected and properly mounted?

--

Go to Step 16

--

16

Clear all the SIR DTCs.

Have all the DTCs been cleared?

--

Go to SIR Diagnostic System Check

--