B0020
DTC B0019 or B0020
Circuit Description
The passenger frontal deployment loop consists of the following components:
* A dual stage inflatable restraint instrument panel (I/P) module
* The I/P module high circuits for both stages 1 and 2
* The I/P module low circuits for both stages 1 and 2
There are 2 shorting bar used within the I/P module connector which will short together both I/P module stage 1 high and low circuits and both I/P module stage 2 high and 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 I/P 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 diagnostic trouble code (DTC) will be stored in memory.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
* DTC B0019 Passenger Frontal Deployment Loop Stage 1
* DTC B0020 Passenger Frontal Deployment Loop Stage 2
Conditions for Running the DTC
Ignition voltage is within the normal operating voltage range.
Conditions for Setting the DTC
B0019 01 Stage 1 or B0020 01 Stage 2
The I/P module high and/or low circuit is short to voltage for 120 milliseconds.
B0019 02 Stage 1 or B0020 02 Stage 2
The I/P module high and/or low circuit is short to ground for 120 milliseconds.
B0019 04 Stage 1 or B0020 04 Stage 2
The I/P module high and/or low circuit is open for 120 milliseconds.
B0019 0D Stage 1 or B0020 0D Stage 2
The I/P module deployment loop resistance is more than 5.1 ohms for 120 milliseconds.
B0019 0E Stage 1 or B0020 0E Stage 2
The I/P module deployment loop resistance is less than 1.3 ohms for 120 milliseconds.
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON via GMLAN serial data.
Conditions for Clearing the MIL/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 between the I/P module stage 1 or stage 2, high and low circuits
* An open or a high resistance in the I/P module stage 1 or stage 2, high or low circuits
* A short to ground or a short to voltage in the I/P module stage 1 or stage 2, high or low circuits
* The I/P module connector
* The SDM connector
* A malfunctioning I/P module
* A malfunctioning SDM
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 Diagnostic Aids. Component Tests and General Diagnostics
Test Description
Step 1 - Step 8:
Step 9:
The numbers below refer to the step numbers on the diagnostic table.
4. This step tests to see if the malfunction is caused by the I/P module.
6. If DTC B0019 01 or B0020 01 is present, test the I/P module for a short to battery voltage on the high and low circuits in stage 1 or stage 2. If DTC B0019 02 or B0020 02 is present, test the I/P module for a short to ground on the high and low circuits in stage 1 or stage 2. If DTC B0019 04, 0D, 0E or B0020 04, 0D, 0E is present, test the high and low circuits for an open circuit and for high or low resistance in stage 1 or stage 2.