GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2001 🢒 Seville - RHD 🢒 DTC 🢒 DTC B0018

Circuit Description

The passenger deployment loop consists of an inflatable restraint IP module, the IP module high and IP module low circuits. A shorting bar is used in the inflatable restraint IP module connector which will short together the IP module high and IP module low circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the inflatable restraint IP module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in non-volatile memory.

Conditions for Running the DTC

Ignition 1 Voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The DTC will set if one of the following conditions occurs:

    • IP module high and/or low circuits is short to ground or short to voltage for 500 milliseconds.
    • IP module high terminal is less than 2.4 volts and IP module deployment loop resistance is less than 6 ohms for 500 milliseconds.

Action Taken When the DTC Sets

The SDM commands the AIR BAG warning indicator ON via Class 2 serial data.

Conditions for Clearing the DTC
    • 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

The following are possible causes of the malfunction:

    • A short to ground or a short to voltage in the IP module circuits
    • A malfunctioning IP module
    • An internal SDM malfunction

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests to see if the malfunction is caused by the inflatable restraint IP module.

    2.

  2. Tests for a short to ground or a short to voltage in the IP module high and IP module low circuits.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

1

Did you perform A Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Disconnect inflatable restraint IP module in-line connector. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  3. Inspect the IP module connector for damage or corrosion that may cause a short to ground or a short to voltage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Does connector exhibits any signs of damage or corrosion?

Go to Step 3

Go to Step 4

3
  1. If the component side of the IP module connector is damaged, the IP module must be replaced. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  2. If the harness side of the IP module connector is damaged, replace the harness side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 9

--

4

  1. Connect the J 38715-A SIR Driver/Passenger Load Tool to the harness side of the IP module connector. Use PASSENGER INFLATOR connector.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC 0018 is current?

Go to Step 5

Go to Step 7

5
  1. Turn OFF the ignition.
  2. Disconnect the J 38715-A .
  3. Disconnect the inflatable restraint sensing and diagnostic module (SDM) connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  4. Inspect the SDM connector for damage or corrosion that may cause a short to ground or a short to voltage. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 6

6

Test the IP module high and IP module low circuits for a short to ground or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 9

Go to Step 8

7
  1. Turn OFF the ignition.
  2. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you complete the replacement?

Go to Step 9

--

8
  1. Turn OFF the ignition.
  2. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

Go to Step 9

--

9
  1. Use the scan tool in order to Clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK