SRS Warning Light Circuit Malfunction CIRCUIT DESCRIPTION The SRS warning light is located on the combination meter. When the SRS is normal, the SRS warning light lights up for approx. 6 seconds after the ignition switch is turned from the LOCK position to ON position, and then turns off automatically. If there is a malfunction in the SRS, the SRS warning light lights up to inform the driver of the abnormality. When terminals Tc and CG of the DLC3 are connected, the DTC is displayed by blinking the SRS warning light.
WIRING DIAGRAM Airbag Sensor Assembly
C13 SRS Warning Light 12 C13
Instrument Panel J/B
14 C13
8 1D
7 1G
B-Y
8
B-R Instrument Panel J/B 8 6 1G 1O
B-Y (W)
3 C4
LA
1P B-Y
B-R
I10 Ignition Switch
Instrument Panel J/B 7 1 1A 1O
W-R
6 A/B
6
5 IG2
AM2
D1 DLC3
ST2
W-R F6 Fusible Link Block
Engine Room R/B 15A AM2 1
1 2
B-L
2
60A MAIN
1 Battery
H12378
2002 ECHO (RM884U)
Author:
Date:
563
DI-394 DIAGNOSTICS
-
SUPPLEMENTAL RESTRAINT SYSTEM
INSPECTION PROCEDURE Always lights up, when ignition switch is in LOCK position 1
Prepare for inspection. (See step 1 on page DI-390 )
2
Does SRS warning light turn off? Airbag Sensor Assembly
LOCK
AB0117
H01293
PREPARATION: (a) Turn the ignition switch to LOCK. (b) Disconnect negative (-) terminal cable from the battery, and wait at least for 90 seconds. (c) Disconnect the airbag sensor assembly connector. (d) Connect negative (-) terminal cable to the battery. CHECK: Check operation of SRS warning light.
H01295
NO
Check SRS warning light circuit or terminal A/B circuit of DLC3.
YES
Replace airbag sensor assembly.
2002 ECHO (RM884U)
Author:
Date:
564
DI-395 DIAGNOSTICS
-
SUPPLEMENTAL RESTRAINT SYSTEM
Does not light up, when ignition switch is turned to ON 1
Check AM2 Fuse.
Fuse
N14677
PREPARATION: Remove AM2 fuse. CHECK: Check continuity of AM2 fuse. OK: Continuity HINT: Fuse may be burnt out even if it appears to be OK during visual inspection. If fuse is OK, install it. NG
Go to step 5.
OK
2
Prepare for inspection. (See step 1 on page DI-390 )
3
Check SRS warning light circuit. Airbag Sensor Assembly ON
(+)
LA
(-) AB0119 H01300
PREPARATION: (a) Connect negative (-) terminal cable to the battery. (b) Turn the ignition switch to ON. CHECK: Measure the voltage between body ground and LA terminal of the harness side connector of the airbag sensor assembly. OK: Voltage: 10 - 14 V
Does SRS warning light come on? PREPARATION: (a) Disconnect negative (-) terminal cable from the battery. (b) Connect the airbag sensor assembly connector. (c) Connect negative (-) terminal cable to the battery, and wait at least for 2 seconds. (d) Turn ignition switch to ON. CHECK: Check operation of SRS warning light.
P/T Squib (RH)
Front Airbag Sensor (RH) D Squib Spiral Cable
P Squib Front Airbag Sensor (LH) P/T Squib (LH) ON Airbag Sensor Assembly
H05047 BE6653 H10589
H13130
NO
Check terminal LA of airbag sensor assembly. If normal, replace airbag sensor assembly.
YES
From the results of the above inspection, the malfunctioning part can now be considered normal. To make sure of this, use simulation method to check.
2002 ECHO (RM884U)
Author:
Date:
566
DI-397 DIAGNOSTICS
5
-
SUPPLEMENTAL RESTRAINT SYSTEM
Is new AM2 fuse burnt out again?
NO
Using simulation method, reproduce malfunction symptoms. (See page IN-19 )
YES
Check harness between AM2 fuse and SRS warning light.
