Inspection Procedure

1. Check the DATA LIST for proper functioning of the stop light switch.

   ECM (cruise control) 

   ITEM MEASUREMENT NORMAL CONDITION CHART
   
   

   Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
   Stp Light SW M-CPU	Stop light switch signal (Main CPU) / ON or OFF	ON: Brake pedal is depressed OFF: Brake pedal is released	-

   OK: 

   OK: Display changes according to brake pedal operation described in above table. 

OK: REPLACE ECM 

NG: Go to next step 

1. Disconnect the stop light switch connector.
2. Measure the resistance of the switch.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Switch Condition	Specified Condition
   1 - 2	Pin not pushed (Brake pedal depressed)	Below 1 Ω
   3 - 4	Pin not pushed (Brake pedal depressed)	10 kΩ or higher
   1 - 2	Pin pushed (Brake pedal released)	10 kΩ or higher
   3 - 4	Pin pushed (Brake pedal released)	Below 1 Ω

NG: REPLACE STOP LIGHT SWITCH 

OK: Go to next step 

1. Disconnect the E5 and E6 ECM connectors.
2. Turn the ignition switch ON.
3. Measure the voltage of the wire harness side connectors.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Brake Pedal Condition	Specified Condition
   E5-4 (STP) - Body ground	Depressed	10 to 14 V
   E5-4 (STP) - Body ground	Released	Below 1 V
   E6-8 (ST1-) - Body ground	Depressed	Below 1 V
   E6-8 (ST1-) - Body ground	Released	10 to 14 V

   Result 

   RESULT REFERENCE CHART
   
   

   Result	Proceed to
   OK	A
   NG (STP terminal is NG)	B
   NG (ST1 - terminal is NG)	C

   Fig 1: Checking Wire Harness (ECM - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

A: REPLACE ECM 

C: REPAIR OR REPLACE HARNESS OR CONNECTOR 

B: Go to next step 

1. Remove the STOP fuse from the driver side junction block ECU.
2. Measure the resistance of the fuse.

   Standard resistance: 

   Below 1 Ω 

NG: REPLACE FUSE 

OK: Go to next step 

1. Disconnect the D2 ECU connector.
2. Measure the voltage of the wire harness side connector.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Brake Pedal Condition	Specified Condition
   D2-13 (STPI) - Body ground	Depressed	10 to 14 V
   D2-13 (STPI) - Body ground	Released	Below 1 V

   Fig 2: Checking Wire Harness (Main Body ECU - Battery)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the D2 ECU connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION
   
   

   Tester Connection	Brake Pedal Condition	Specified Condition
   D2-12 (STPO) - Body ground	Depressed	10 to 14 V
   D2-12 (STPO) - Body ground	Released	Below 1 V

   Fig 3: Identifying D2 Driver Side Junction Block Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE MAIN BODY ECU (for Driver Side) 

OK: REPAIR OR REPLACE HARNESS OR CONNECTOR (MAIN BODY ECU - ECM)