Inspection Procedure

WARNING: This page is about a different car, the 2005 Lexus GS 430 and 2005 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

Check voltage between terminals CCS of ECM connector and body ground.

PREPARATION:

Remove the ECM with connector still connected.
Turn the ignition switch to ON.

CHECK:

Measure voltage between terminals CCS of ECM connector and body ground, when each of the SET/COAST, RESUME/ ACCEL and CANCEL is turned ON.

CCS AND BODY GROUND

Switch position	Voltage (V)
Neutral	10 - 16V
RES/ACC	2.3 - 4.5 V
SET/COAST	4.5 - 8.1 V
CANCEL	6.6 - 11.4V

Fig 1: Checking Voltage Between Terminal CCS Of ECM Connector And Body Ground

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Proceed to next circuit inspection shown in problem symptoms table (See PROBLEM SYMPTOMS TABLE ).
OK: Go to next step.

Check control switch continuity.

PREPARATION:

Remove the steering wheel pad (See REMOVAL ).
Disconnect the control switch connector.

Measure the resistance between terminals 4 and 5 of control switch connector when control switch is operated.

CONTROL SWITCH CONTINUITY

Switch position	Resistance (Ω.)
Neutral	infin (No continuity)
RES/ACC	220 - 260
SET/COAST	600 - 660
CANCEL	1,500 - 1,600

Fig 2: Checking Control Switch Continuity

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: Replace control switch.
OK: Go to next step.

Check main switch continuity.

PREPARATION:

Remove the steering wheel pad (See REMOVAL ).
Disconnect the control switch connector.

CHECK:

Check the continuity between terminals 4 and 5 of control switch connector when main switch is held ON and OFF.

OK:

MAIN SWITCH CONTINUITY

Switch position	Tester connection	Specified condition
OFF	-	No continuity
Hold ON	4 - 5	Continuity

Fig 3: Checking Main Switch Continuity

NG: Replace control switch.
OK: Go to next step.

Check harness and connector between ECM and cruise control switch, cruise control switch and body ground (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).
1. NG: Repair or replace harness or connector.
2. OK: Go to next step.
Check cruise control indicator light (See COMBINATION METER ).
1. NG: Replace combination meter.
2. OK: Check and replace ECM (See HOW TO USE THE DIAGNOSTIC CHART AND INSPECTION PROCEDURE ).