SRS Warning Light Does Not Come ON

SUPPLEMENTAL RESTRAINT SYSTEM: AIRBAG SYSTEM: SRS Warning Light does not Come ON

SRS Warning Light does not Come ON

DESCRIPTION

The SRS warning light is located on the combination meter assembly.
When the SRS condition is normal, the SRS warning light illuminates for approximately 6 seconds after the ignition switch is turned from off to on, and then goes off automatically.
If there is a malfunction in the SRS, the SRS warning light illuminates or blinks to inform the driver of the problem. When terminals TC and CG of the DLC3 are connected, the SRS warning light blinks to indicate DTCs.
The center airbag sensor assembly is equipped with a voltage-increase circuit (DC-DC converter) in case the source voltage decreases. When the battery voltage decreases, the voltage-increase circuit (DC-DC converter) boosts the SRS voltage up to the normal level.
Malfunctions relating to battery voltage decreases cause the SRS warning light to illuminate, however, no DTCs are recorded in the center airbag sensor assembly. The SRS warning light goes off automatically when the source voltage returns to normal.
Signals to illuminate the SRS warning light are transmitted from the center airbag sensor assembly to the combination meter assembly.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK BATTERY
(a) Measure the voltage of the battery.
Standard Voltage:

NG -- CHECK AND REPLACE BATTERY OR CHARGING SYSTEM
OK -- Continue to next step.
2. CHECK CONNECTOR (INSTRUMENT PANEL WIRE - COMBINATION METER)
(a) Turn the ignition switch off.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the instrument panel wire connector from the combination meter assembly.
(d) Check the instrument panel wire connector and terminals (on the combination meter side) and check that the connector is properly connected to the combination meter assembly.
Result:

C -- CONNECT CONNECTOR PROPERLY
B -- REPAIR OR REPLACE INSTRUMENT PANEL WIRE
A -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SOURCE VOLTAGE OF COMBINATION METER)
(a) Disconnect the connector from the combination meter assembly.
(b) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.

(d) Turn the ignition switch off.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK CONNECTOR (INSTRUMENT PANEL WIRE - CENTER AIRBAG SENSOR ASSEMBLY)
(a) Turn the ignition switch off.
(b) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(c) Disconnect the instrument panel wire connector from the center airbag sensor assembly.
(d) Check the instrument panel wire connector and terminals (on the center airbag sensor assembly side) and check that the connector is properly connected to the center airbag sensor assembly.
Result:

C -- CONNECT CONNECTOR PROPERLY
B -- REPAIR OR REPLACE INSTRUMENT PANEL WIRE
A -- Continue to next step.
5. CHECK INSTRUMENT PANEL WIRE

(a) Disconnect the connectors from the center airbag sensor assembly and combination meter assembly.
(b) Check for short to B+ in the circuit.
(1) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(2) Turn the ignition switch to ON.
(3) Measure the voltage according to the value(s) in the table below.
Standard Voltage:

(c) Check for open in the circuit.
(1) Turn the ignition switch off.
(2) Disconnect the negative (-) terminal cable from the battery, and wait for at least 90 seconds.
(3) Measure the resistance according to the value(s) in the table below.
Standard Resistance:

(d) Check for short to ground in the circuit.
(1) Measure the resistance according to the value(s) in the table below.
Standard Resistance:

NG -- REPAIR OR REPLACE INSTRUMENT PANEL WIRE
OK -- Continue to next step.
6. CHECK SRS WARNING LIGHT
(a) Connect the connector to the combination meter assembly.
(b) Connect the negative (-) terminal cable to the battery, and wait for at least 2 seconds.
(c) Turn the ignition switch to ON.
(d) Check the SRS warning light condition.
OK:
The SRS warning light goes off after the primary check period and comes on again after approximately 10 seconds.
HINT: The primary check period lasts for approximately 6 seconds after the ignition switch is turned on.

NG -- REPLACE COMBINATION METER ASSEMBLY
OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY