B1112

CIRCUIT DESCRIPTION
Since the source voltage can fluctuate, the SRS is equipped with a voltage-increase/voltage-decrease circuit (DC/DC converter) in the SRSCM to adjust for any fluctuations in the source voltage. When the battery voltage fluctuates, the DC/ DC converter adjust the voltage to the SRS by either increasing or decreasing to maintain normal system voltage. The diagnosis system malfunction display for this circuit is different than other circuits-when the SRS warning lamp remains lit up and the DTC is a Bill 1 or Bill 2 code, battery voltage too high or low is indicated.

Malfunction in this circuit is not recorded in the Bill 1 or Bill 2 code, battery voltage too high or low, and the voltage returns to normal, the SRS warning light automatically goes off.

INSPECTION PROCEDURE




1. Preparation.

1. Disconnect negative (-) terminal cable from the battery, and wait at least 30 seconds.
2. Remove the DAB module.
3. Disconnect connectors of PAB left and right side airbag, belt pretensioner and satellite sensor.
4. Disconnect connector of SRSCM.

CAUTION: Store the DAB with the front surface facing upward.




2. Check source voltage.
1. Connect negative (-) terminal cable to battery.
2. Turn ignition switch ON.

CHECK: Measure voltage between the battery supply 5 of SRS connector and body ground.

LIMIT: 10 - 16.5 V

NG: Check the harness between battery and SRSCM, and check the battery and charging system.

OK: Continue to next step.

3. Does SRS warning light turn off?

PREPARATION
1. Turn ignition switch to LOCK.
2. Connect the DAB module.
3. Connect PAB connector, left and right side airbag, belt pretensioner and satellite connectors.
4. Connect SRSCM connector.
5. Turn ignition switch ON.

CHECK: Check that SRS warning light goes off.

NG: Check for DTCs. If a DTC is output, perform troubleshooting for the DTC. If Bill 1 or Bill 2 is output, replace SRSCM.

OK: From the results of the above inspection, the malfunctioning part can now be considered normal.