B0066

DTC B0066

CIRCUIT DESCRIPTION




The driver seat belt pretensioner deployment loop consists of a seat belt pretensioner-LF and the seat belt pretensioner-LF high and low circuits. A shorting bar used within the seat belt pretensioner connector shorts together both the seat belt pretensioner high and low circuits when the connector is disconnected. This will help to prevent unwanted deployment of the pretensioner 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 seat belt pretensioner. 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.

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
- DTC B0064 will set when the seat belt pretensioner-LF deployment loop resistance is less than 1.3 ohms for 500 milliseconds.
- DTC B0065 will set when one of the following conditions occurs:
- Seat belt pretensioner-LF high circuit is less than 2.4 volts and the seat belt pretensioner-LF deployment loop is more than 6 ohms for 500 milliseconds.
- Seat belt pretensioner-LF deployment loop resistance is more than 4.8 ohms for 500 milliseconds.
- DTC B0066 will set when one of the following conditions occur:
- Seat belt pretensioner-LF high or low circuits is short to ground or short to voltage for 500 milliseconds.
- Seat belt pretensioner-LF high circuit is less than 2.4 volts and seat belt pretensioner-LF deployment loop resistance is less than 6 ohms for 500 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands the AIR BAG 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 between the seat belt pretensioner-LF high and low circuits.
- An open or a high resistance in the seat belt pretensioner-LF high or low circuits.
- A short to ground or a short to voltage in the seat belt pretensioner-LF high or low circuits.
- The seat belt pretensioner-LF connector
- The SDM connector
- A malfunctioning seat belt pretensioner
- 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 and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-7:

Steps 8-11:

The numbers below refer to the step numbers on the diagnostic table.
4. Tests to see if the malfunction is caused by the seat belt pretensioner-LF.
7. Tests to see what DTCs are present. If DTC B0064 is present, test for a short between the seat belt pretensioner-LF high and low circuits. If DTC B0065 is present, test the seat belt pretensioner-LF high and low circuits for an open and for high resistance. If DTC B0066 is present, test the seat belt pretensioner-LF high and low circuits for a short to ground and for a short to voltage.