Inspection Procedure

1. Delete the DTCs (See DTC CHECK / CLEAR  ).

   HINT:

   After all DTCs are cleared, turn the engine switch on (IG) and depress the brake pedal. After 15 seconds have elapsed, check if the trouble occurs again.

2. Check for DTCs again.

   OK: No DTC is output. 

NG: Go to step 2 

OK: CHECK INTERMITTENT PROBLEMS 

1. Disconnect the E58 ECU connector.
   Fig 1: Disconnecting A10 ECM Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the A10 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   RESISTANCE SPECIFICATION
   
   

   Terminal No. (Symbol)	Condition	Specified Condition
   E58-4 (STSW) - A10-14 (STSW)	Always	Below 1 Ω
   E58-4 (STSW) - Body ground	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to Next Step 

1. Reconnect the connectors.
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage 

   VOLTAGE SPECIFICATION
   
   

   Terminal No. (Symbol)	Condition	Specified Condition
   E58-4 (STSW) - Body ground	Brake pedal depressed, Engine switch hold on (ST)	Output voltage at terminal AM1 or AM2 is -2 V or more.

Fig 2: Identifying Main Body ECU Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE MAIN BODY ECU 

OK: Go to Next Step 

1. After replacing the main body ECU with a normally functioning ECU, check that the engine can start. Make sure the brake pedal is depressed and the shift position is P at this time.
2. Check that the engine switch mode can be changed by pushing the engine switch.

   HINT:

   Without depressing the brake pedal, push the engine switch repeatedly. Engine switch mode should turn from off to on (ACC) to on (IG) and back to off. With the brake pedal depressed, push the engine switch repeatedly.

   Engine switch mode should turn to ENGINE START from any status.

   OK: Engine can start normally. 

   HINT:

   If engine does not start, (See ENGINE DOES NOT START  ).

NG: GO TO OTHER PROBLEM 

OK: END (MAIN BODY ECU DEFECTIVE)