B1818

DTC B1815, B1816, B1817, or B1818

Circuit Description

The inflatable restraint instrument panel (I/P) module deployment loop consists of a dual stage inflatable restraint I/P module, the I/P module high and I/P module low circuits. There are 2 shorting bar used in the inflatable restraint I/P module connector which will short together the I/P module - high and I/P module low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (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.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

* DTC B1815 Passenger Air Bag Deployment Loop Resistance Too Low Circuit 2
* DTC B1816 Passenger Air Bag Deployment Loop Resistance Too High Circuit 2
* DTC B1817 Passenger Air Bag Deployment Loop Short To Ground Circuit 2
* DTC B1818 Passenger Air Bag Deployment Loop Short To Battery Circuit 2

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

* DTC B1815 will set when the SDM detects a low resistance condition in the I/P module deployment loop.
* DTC B1816 will set when the SDM detects a high resistance condition in the I/P module deployment loop.
* DTC B1817 will set when the SDM detects a short to ground in the I/P module deployment loop.
* DTC B1818 will set when the SDM detects a short to voltage in the I/P module deployment loop.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Diagnostic Aids

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.

The following are possible causes of the malfunction:

* A short between the I/P module - high and the I/P module - low circuits
* An open or high resistance in the I/P module - high or the I/P module - low circuits
* A short to ground in the I/P module - high or the I/P module - low circuits
* A short to voltage in the I/P module - high or the I/P module - low circuits
* A malfunctioning inflatable restraint I/P module
* An internal SDM malfunction

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics

Test Description

Step 1 - Step 12:

Step 13:

The numbers below refer to the step numbers on the diagnostic table.
7. This step tests to see if the malfunction is caused by the inflatable restraint I/P module.
8. This step tests to see if the malfunction is caused by the inflatable restraint I/P module.
10. If DTC B1815 is present, test for a short between the I/P module high and I/P module low circuits.
If DTC B1816 is present, test the I/P module high and I/P module low circuits for an open or high resistance.
If DTC B1817 is present, test the I/P module high and I/P module low circuits for a short to ground.
If DTC B1818 is present, test the I/P module high and I/P module low circuits for a short to voltage.