Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

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

PREPARATION:

Remove the ECM with connector being connected.
Turn ignition switch ON.

CHECK:

Measure voltage between terminal CCS of ECM connector and body ground, when each of the -/SET, +/RES and CANCEL is turned ON.

OK:

SWITCH POSITION VOLTAGE

Switch Position	Voltage
Neutral	9-14V
+/RES	2.1 -4V
-/SET	4-7.1 V
CANCEL	6-10.1 V

Fig 1: Identifying ECM Connector Terminal CCS

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : Proceed to next circuit Inspection shown on problem symptom table (See PROBLEM SYMPTOMS TABLE ).
NG : Go To Next Step

Check main switch continuity.

PREPARATION:

Remove steering wheel center pad (See STEERING WHEEL ).
Disconnect the control switch connector.

CHECK:

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

SWITCH POSITION RESISTANCE

Switch position	Resistance (Ω)
Neutral	INFINITY (No continuity)
+/RES	210-270
-/SET	560-700
CANCEL	1380-1700

Check continuity between terminal 4 and 5 of the control switch connector when the main switch is held on and off.

OK:

SWITCH POSITION SPECIFIED CONDITION

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

Fig 2: Identifying Terminals 4 & 5 Of Cruise Control Switch Connector

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 PROCEED WITH TROUBLESHOOTING ).
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 ).