GM Service Manual Online
For 1990-2009 cars only

Object Number: 605771  Size: SF
SIR Components
2000 J SIR
SIR Handling Caution
Handling ESD Sensitive Parts Notice

Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) monitors the front end discriminating sensor circuit for front impact detection. The SDM processes the signal provided by the front end discriminating sensor to further support deployment of the air bags. The front end discriminating sensor is an input only to the SDM and does not directly cause air bag deployment. When you first turn the ignition ON, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM then performs the following continuous diagnostic tests on the deployment loops:

    • Deployment loop voltage out of range test
    • Deployment loop resistance measurement test

If the voltage out of range test detects a short to voltage condition, the resistance measurement test for that deployment loop will not be performed.

Conditions for Running the DTC

    • Ignition voltage is within the normal operating voltage range.
    • The SDM monitors the inflatable restraint front end discriminating sensor with the ignition ON.

Conditions for Setting the DTC

The voltage at the discriminating sensor signal input is greater than 3.65 volts for 300 milliseconds.

Action Taken When the DTC Sets

    • The SDM disables the discriminating sensor input.
    • The SDM commands ON the AIR BAG warning lamp via Class 2 serial data.

Conditions for Clearing the DTC

    • The voltage at the discriminating sensor signal input is 3.65 volts or less for 300 milliseconds.
    • The condition responsible for setting the DTC no longer exists, and the Scan Tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.

Diagnostic Aids

A short to battery or an open condition in the inflatable restraint front end discriminating sensor loop can cause an intermittent condition. Inspect the inflatable restraint front end discriminating sensor circuits carefully for cutting or chafing. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

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

  1. This step checks the inflatable restraint front end discriminating sensor wiring harness connector.

  2. This step checks the inflatable restraint front end discriminating sensor.

  3. This step checks the inflatable restraint sensing and diagnostic module (SDM) wiring harness connector.

  4. This step checks for an open or a high resistance in the inflatable restraint front end discriminating sensor input circuit.

  5. This step checks for an open or a high resistance in the inflatable restraint front end discriminating sensor return circuit.

  6. This step checks for a short to B+ in the inflatable restraint front end discriminating sensor input circuit.

  7. This step determines if there is an open or a high resistance in the inflatable restraint front end discriminating sensor return circuit or if there is a malfunctioning SDM.

DTC B0036 ADS Open/Missing or Shorted to Battery

Step

Action

Value(s)

Yes

No

1

Did you perform the SIR Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Disconnect the inflatable restraint front end discriminating sensor. Refer to Inflatable Restraint Front End Discriminating Sensor Replacement .
  3. Inspect the male and female sides of the inflatable restraint front end discriminating sensor connector for the following conditions:
  4. • Corrosion
    • Damaged terminals
    • Poor connection/terminal tension

Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Does the inflatable restraint front end discriminating sensor connector exhibit any signs of corrosion, terminal damage, or poor connections?

--

Go to Step 3

Go to Step 4

3

Replace the inflatable restraint front end discriminating sensor connector. Refer to Connector Repairs .

Did you complete the replacement?

--

Go to Step 17

--

4

Use the J 39200 Digital Multimeter (DMM) to measure the resistance between the inflatable restraint front end discriminating sensor terminals.

Does the resistance measure within the specified values?

900 - 1100 ohms

Go to Step 6

Go to Step 5

5

Replace the inflatable restraint front end discriminating sensor. Refer to Inflatable Restraint Front End Discriminating Sensor Replacement .

Did you complete the replacement?

--

Go to Step 17

--

6

  1. Disconnect the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Inspect the SDM wiring harness connector for the following conditions:
  3. • Corrosion
    • Damaged terminals
    • Poor connections/terminal tension

Does the SDM wiring harness connector exhibit any signs of corrosion, terminal damage, or poor connections?

--

Go to Step 7

Go to Step 8

7

Replace the SDM wiring harness connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 17

--

8

Use the DMM to measure the resistance of the inflatable restraint front end discriminating sensor input circuit.

Does the resistance measure less than the specified value?

2 ohms

Go to Step 10

Go to Step 9

9

Locate and repair the open or the high resistance in the inflatable restraint front end discriminating sensor input circuit.

Did you complete the repair?

--

Go to Step 17

--

10

Use the DMM to measure the resistance of the inflatable restraint front end discriminating sensor return circuit.

Does the resistance measure less than the specified value?

2 ohms

Go to Step 12

Go to Step 11

11

Locate and repair the open or the high resistance in the inflatable restraint front end discriminating sensor return circuit.

Did you complete the repair?

--

Go to Step 17

--

12

  1. Turn ON the ignition, with the engine OFF.
  2. Use the DMM to measure the voltage between the inflatable restraint front end discriminating sensor input circuit and a known good ground.

Does the voltage measure more than the specified value?

1 V

Go to Step 13

Go to Step 14

13

Locate and repair the short to voltage in the inflatable restraint front end discriminating sensor input circuit.

Did you complete the repair?

--

Go to Step 17

--

14

Use the DMM to measure the voltage between the inflatable restraint front end discriminating sensor return circuit and a known good ground.

Does the voltage measure more than the specified value?

1 V

Go to Step 15

Go to Step 16

15

Locate and repair the short to voltage in the inflatable restraint front end discriminating sensor return circuit.

Did you complete the repair?

--

Go to Step 17

--

16

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the repair?

--

Go to Step 17

--

17

  1. Reconnect all SIR system components.
  2. Verify that all components and connectors are properly mounted.
  3. Turn On the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.
  5. Also, clear all communication DTCs in all modules that communicate with the SDM.

Does the DTC reset?

--

Go to Diagnostic System Check - SIR

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