Ignition Switch Circuit: Procedure

1. Using the Techstream, read the Data List.
   MAIN BODY
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   IG SW	Ignition switch / ON or OFF	ON: Ignition switch ON OFF: Ignition switch OFF	-

   OK

   When the ignition switch is operated, "ON" is displayed on the Techstream screen.

NG → See step   2 

OK → See step   6 

1. Remove the AM1 and ECU-IG No. 2 fuses from the main body ECU.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   AM1 fuse	Always	Below 1 Ω
   ECU-IG No. 2 fuse

NG → REPLACE FUSE 

OK: Go to next step 

1. Disconnect the DA main body ECU connector.
   Fig 1: Identifying DA Main Body ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   DA-1 (IG) - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

Fig 2: Identifying Ignition Switch Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the ignition switch.
   1. For 1GR-FE, refer to the following procedures. Refer to REMOVAL .
   2. For 1UR-FE, refer to the following procedures. Refer to REMOVAL .
   3. For 3UR-FE, refer to the following procedures. Refer to REMOVAL .
   4. For 3UR-FBE, refer to the following procedures. Refer to REMOVAL .
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Switch Condition	Specified Condition
   1 (IG1) - 4 (AM1)	Ignition switch ON	Below 1 Ω

   RESULT
   
   

   Result	Proceed to
   OK	A
   NG (for 1GR-FE)	B
   NG (for 1UR-FE)	C
   NG (for 3UR-FE)	D
   NG (for 3UR-FBE)	E

B → See step   7 

C → See step   8 

D → See step   9 

E → See step   10 

A: Go to next step 

Fig 3: Checking Harness And Connector (Main Body ECU -- Ignition Switch And Body Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the DD main body ECU connector.
2. Disconnect the J9 ignition switch connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   DD-47 - J9-4 (AM1)	Always	Below 1 Ω
   DD-43 - J9-1 (IG1)
   DD-62 - Body ground
   DD-47 - Body ground	Always	10 kΩ or higher
   DD-43 - Body ground

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → REPLACE MAIN BODY ECU