Inspection Procedure

WARNING: This page is about a different car, the 2004 Lexus GS 430 and 2004 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

If the DTC is not displayed, do the following troubleshooting.

Does SRS warning light up for approx. 6 seconds?
PREPARATION:

Check operation of the SRS warning light after ignition switch is turned from LOCK position to ON position.

Fig 1: Checking Operation Of SRS Warning Light
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. NO: Check SRS warning light system (See SRS WARNING LIGHT CIRCUIT MALFUNCTION ).
2. YES: Go to Next Step.
Check voltage between terminals TC and CG of DLC3.
PREPARATION:

Turn the ignition switch to ON.

CHECK:

Measure the voltage between terminal TC and CG of DLC3.

OK:

Voltage: 10-14 V

Fig 2: Measuring Voltage Between Terminal TC And CG Of DLC3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
1. OK: Go to step 4 .
2. NG: Go to Next Step.
Check voltage between terminal TC of DLC3 and body ground.

Fig 3: Checking Voltage Between Terminal TC Of DLC3 And Body Ground
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

CHECK:

Measure the voltage between terminal TC of DLC3 and body ground.

OK:

Voltage: 10-14 V
1. OK: Check or repair harness between terminal CG of DLC3 and body ground.
2. NG: Go to Next Step.
Check multiplex communication system (See INSPECTION ).
Check airbag sensor assembly.
CHECK:

Check the DTC (See PRE-CHECK ).

OK:

DTC is output.
1. NG: Replace airbag sensor assembly.
2. OK: Go to next step.
  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.

If the DTC is displayed without a DTC check procedure, perform the following troubleshooting.

Check and repair wire harness between the engine ECU and DLC3.
Is DTC output again?
CHECK:
1. Turn the ignition switch to LOCK, and wait at least for 5 seconds.
2. Turn the ignition switch to ON, and wait at least for 10 seconds.
3. Check SRS warning light.
1. YES: Replace airbag sensor assembly.
2. NO: Go to next step.
  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.