B2504

DTC Description

The SRS warning lamp is located in the cluster. When the airbag system is normal, the SRS warning lamp turns on for approx. 6 seconds after the ignition switch is turned to ON, and then turns off automatically. If there is a malfunction in the airbag system, the SRS warning lamp lights up to inform the driver of the abnormality. The SRSCM shall measure the voltage at the SRS warning lamp output pin, both when the lamp is on and when the lamp is off, to detect whether the commanded state matches the actual state.

DTC Detecting Condition





Schematic Diagram





Terminal & Connector Inspection

Refer to the DESCRIPTION in this TROUBLESHOOTING section.

Inspection Procedure

1. PREPARATION
Refer to the DESCRIPTION in this TROUBLESHOOTING section.
2. CHECK THE FUSE
(1) Remove the airbag fuse and the airbag warning lamp fuse from junction box.
(2) Inspect the fuses. Are the fuses normal?
YES
> Check the warning lamp bulb.
NO
> Repair or replace the fuses.
3. CHECK THE WARNING LAMP BULB
(1) Remove the bulb from the instrument cluster.
(2) Inspect the bulb. Is the bulb normal?
YES
>Check source voltage.
NO
> Repair or replace the bulb.
4. CHECK SOURCE VOLTAGE
(1) Connect the battery negative cable to the battery.
(2) Turn the ignition switch to ON.
(3) Measure voltage between the terminal 5 of the Instrument Cluster harness connector and chassis ground.

Specification (voltage) : 9 - 16 V





(4) Is the measured voltage within specification?
YES
>Check short to battery line.
NO
>Repair or replace the wiring harness between ignition switch and the Warning Lamp.
5. CHECK SHORT TO BATTERY LINE
(1) Measure voltage between the terminal 4 of the Instrument Cluster harness connector and chassis ground.

Specification (voltage) : Approximately 0 V





(2) Is the measured voltage within specification?
YES
> Check short or short to ground.
NO
> Repair the short to battery line circuit on wiring harness between the SRSCM and the Warning Lamp.
6. CHECK SHORT OR SHORT TO GROUND
(1) Turn the ignition switch to LOCK.
(2) Disconnect the battery negative cable from the battery.
(3) Measure resistance between the terminal 4 of the Instrument Cluster harness connector and chassis ground.
(4) Measure resistance between the terminal 4 and 5 of the Instrument Cluster harness connector.

Specification (resistance) : infinite





(5) Is the measured resistance within specification?
YES
>Check open circuit.
NO
> Repair the short or short to ground circuit on wiring harness between the SRSCM and the Warning Lamp.
7. CHECK OPEN CIRCUIT
(1) Measure resistance between the terminal 4 of the Instrument Cluster connector and the terminal 15 of SRSCM harness connector(A).

Specification (resistance) : below 1 Ohms





(2) Is the measured resistance within specification?
YES
> Go to next step.
NO
> Repair the open circuit on wiring harness between the SRSCM and the Warning Lamp.
8. CLEAR THE DTC AND CHECK THE VEHICLE AGAIN
Refer to the DESCRIPTION in this TROUBLESHOOTING section.