Immobilizer System does not Operate Properly [11/2021 - ]: Procedure

1. Check for DTCs.

   Body Electrical > Smart Access > Trouble Codes 

   Powertrain > Engine > Trouble Codes 

   Result

   Result	Proceed to
   DTCs are not output	A
   DTCs are output	B

Result: 

B 

GO TO DIAGNOSTIC TROUBLE CODE CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [11/2021 - 03/2023]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [03/2023 - ] 

Result: 

A 

See step  2

1. Read the Data List according to the display on the GTS.

   Powertrain > Engine > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Immobilizer Fuel Cut Status	Immobilizer fuel cut status	OFF or ON	OFF: Fuel cut OFF ON: Fuel cut ON	-

   Powertrain > Engine > Data List 

   Tester Display
   Immobilizer Fuel Cut Status

   Result

   Result	Proceed to
   On the GTS screen, ON is displayed.	A
   On the GTS screen, OFF is displayed.	B

Result: 

A 

GO TO SFI SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) 

for A25A-FKS: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ]

for T24A-FTS: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ]

Result: 

B 

See step  3

1. Check that the engine starts after 5 seconds of the ignition switch being turned to ON.

   OK

   Engine starts normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2021 - ] 

Result: 

NG 

See step  4

1. Disconnect the D62 ID code box (immobilizer code ECU) connector.
2. Disconnect the A20*1 or A19*2 ECM connector.
   1. *1: for A25A-FKS
   2. *2: for T24A-FTS
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   FOR A25A-FKS
   
   

   Tester Connection	Condition	Specified Condition
   A20-25 (IMO) - D62-3 (EFII)	Always	Below 1 Ω
   A20-25 (IMO) or D62-3 (EFII) - Other terminals and body ground	Always	10 kΩ or higher
   A20-26 (IMI) - D62-4 (EFIO)	Always	Below 1 Ω
   A20-26 (IMI) or D62-4 (EFIO) - Other terminals and body ground	Always	10 kΩ or higher

   FOR T24A-FTS
   
   

   Tester Connection	Condition	Specified Condition
   A19-37 (IMO) - D62-3 (EFII)	Always	Below 1 Ω
   A19-37 (IMO) or D62-3 (EFII) - Other terminals and body ground	Always	10 kΩ or higher
   A19-38 (IMI) - D62-4 (EFIO)	Always	Below 1 Ω
   A19-38 (IMI) or D62-4 (EFIO) - Other terminals and body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  5

1. Connect the A20*1 or A19*2 ECM connector.
   1. *1: for A25A-FKS
   2. *2: for T24A-FTS
2. Connect the D62 ID code box (immobilizer code ECU) connector.
3. Using an oscilloscope, check the waveform.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component with harness connected (ID Code Box (Immobilizer Code ECU))	*b	Approximately 160 ms.
   *c	Approximately 270 ms.	*d	Approximately 40 ms.
   *e	Approximately 60 ms.	*f	Waveform (EFII)
   *g	Waveform (EFIO)	*h	Waveform 1
   *i	Waveform 2	*j	Waveform 3
   *k	Waveform 1 (detail)	-	-

   NOTE:

   The waveform shown in the illustration is an example for reference only. Noise, chattering, etc. are not shown.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   D62-3 (EFII) - Body ground	Within 3 seconds of engine start or within 3 seconds of ignition switch turned to ON after auxiliary battery cable disconnected and reconnected	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform 2)
   D62-4 (EFIO) - Body ground	Within 3 seconds of engine start or within 3 seconds of ignition switch turned to ON after auxiliary battery cable disconnected and reconnected	2 V/DIV., 500 ms./DIV.	Pulse generation (See waveform 1 and 3)

   Result

   Result	Proceed to
   Normal waveform	A
   Waveform 1 is not output, or has abnormal wavelength or shape	B
   Waveform 2 or is not output, or has abnormal wavelength or shape	C

Result: 

B 

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [11/2021 - ] 

Result: 

C 

REPLACE ECM 

for A25A-FKS: Refer to REMOVAL [11/2021 - ]

for T24A-FTS: Refer to REMOVAL [11/2021 - ]

Result: 

A 

See step  6

1. Register the ECU communication ID codes.

   Refer to REGISTRATION [11/2021 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  7

1. Check that the engine starts.

   OK

   Engine starts normally.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE) 

Result: 

NG 

REPLACE ID CODE BOX (IMMOBILIZER CODE ECU). Refer to  REMOVAL [11/2021 - ]