Smart Access System (Keyless Start) (Diagnostic Codes & Symptom Tests): Wiring Lexus GS III facelift

WIRING DIAGRAM

See CRANKING HOLDING FUNCTION CIRCUIT Refer to Cranking Holding Function Circuit .

Scheme 113

Scheme 114

Scheme 115

Scheme 116

1. CHECK FOR DTC Delete the DTCs. HINT: After all DTCs are cleared, check if the trouble occurs again 5 seconds after the engine switch is turned on (IG). Check for DTCs again. OK No DTC is output. NG --> GO TO DTC CHART OK: Go to next step
2. CHECK BASIC FUNCTION When there is fuel in the fuel tank, the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal causes the engine to start. OK Engine starts. NG --> See step 3 OK --> END
3. CHECK SWITCH CONDITION When the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal while pressing the engine switch causes the power source mode to change as follows. OK off --> on (ACC) --> on (IG) --> off NG --> GO TO POWER SOURCE MODE DOES NOT CHANGE OK: Go to next step
4. CHECK BASIC FUNCTION When there is fuel in the fuel tank, the key is inside the vehicle and the shift lever is on P, check that depressing the brake pedal and pressing the engine switch cranks the engine. OK Engine cranks. NG --> See step 5 OK --> GO TO ENGINE IMMOBILISER SYSTEM
5. CHECK STEERING LOCK SYSTEM When the engine switch is on (ACC), check that the steering lock can be released. OK Steering lock can be released. NG --> GO TO STEERING LOCK SYSTEM OK: Go to next step
6. CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - PNP SWITCH) Disconnect the K73 ECU connector. Disconnect the E77 switch connector. Measure the resistance of the wire harness side connectors. Standard resistance Tester Connection Specified Condition K73-17 (STR1) - E77-4 Below 1 ohms K73-17 (STR1) or E77-4 - Body ground 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS AND CONNECTOR OK: Go to next step
7. CHECK WIRE HARNESS (ENGINE ROOM R/B NO. 2 - POWER SOURCE CONTROL ECU) Remove the ST CUT relay from the engine room R/B No. 2. Disconnect the K73 ECU connector. Measure the resistance of the wire harness side connectors. Standard resistance Tester Connection Specified Condition Engine room R/B No. 2 ST CUT relay terminal 3 - K73-15 (STR2) Below 1 ohms Engine room R/B No. 2 ST CUT relay terminal 3 or K73-15 (STR2) - Body ground 10 kohms or higher Standard resistance Tester Connection Specified Condition Engine room R/B No. 2 ST CUT relay terminal 2- K73-35 (IG2D) Below 1 ohms Engine room R/B No. 2 ST CUT relay terminal 2 or K73-35 (IG2D) - Body ground 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS AND CONNECTOR OK: Go to next step
8. CHECK WIRE HARNESS (POWER SOURCE CONTROL ECU - ECM) Disconnect the K73 ECU connector. Disconnect the A6 ECM connector. Measure the resistance of the wire harness side connectors. Standard resistance Tester Connection Specified Condition K73-28 (SKSW) - A6-31 (KSW) Below 1 ohms K73-28 (SKSW) or A6-31 (KSW) - Body ground 10 kohms or higher NG --> REPAIR OR REPLACE HARNESS AND CONNECTOR OK: Go to next step
9. CHECK POWER SOURCE CONTROL ECU Reconnect the K73 ECU connector. Measure the voltage of the ECU. Standard voltage Tester Connection Condition Specified Condition K73-39 (STSW) - Body ground Engine switch on (IG) 10 to 14 V NG --> REPAIR OR REPLACE HARNESS AND CONNECTOR OK --> GO TO SFI SYSTEM