Toyota Tacoma Quiz
Engine Immobiliser

Engine Immobiliser System Malfunction (B2799,B279986)

In this manual: Engine Immobiliser
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~9min read
DESCRIPTION

This DTC is stored when one of the following occurs: 1) the ECM detects errors in its own communication with the transponder key ECU assembly; 2) the ECM detects errors in the communication lines; or 3) the ECU communication ID between the transponder key ECU assembly and ECM is different and an engine start is attempted.

DTC No.

DTC Detection Condition

Trouble Area

DTC Output Confirmation Operation

B2799*1

One of the following conditions is met:

  • Error in communication between ECM and transponder key ECU assembly.
  • Error in communication lines.
  • Communication ID is different during communication between ECM and transponder key ECU assembly.
  • Wire harness or connector
  • ECM
  • Transponder key ECU assembly
  • Start the engine and wait 10 seconds.
  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.

B279986*2

One of the following conditions is met:

  • Error in communication between ECM and transponder key ECU assembly.
  • Error in communication lines.
  • Communication ID is different during communication between ECM and transponder key ECU assembly.
  • Wire harness or connector
  • ECM
  • Transponder key ECU assembly
  • Start the engine and wait 10 seconds.
  • After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.
  • *1: for 2TR-FE
  • *2: for 2GR-FKS
Vehicle Condition and Fail-safe Operation when Malfunction Detected

Vehicle Condition when Malfunction Detected

Fail-safe Operation when Malfunction Detected

Engine cannot be started

-
Related Data List and Active Test

DTC No.

Data List and Active Test

B2799*1

-

B279986*2

-
  • *1: for 2TR-FE
  • *2: for 2GR-FKS
WIRING DIAGRAM CAUTION / NOTICE / HINT CAUTION / NOTICE / HINT

NOTICE:

  • If the transponder key ECU assembly or ECM is replaced, refer to Registration (See page After repair, confirm that no DTCs are output by performing "DTC Output ).
  • After repair, confirm that no DTCs are output by performing "DTC Output Confirmation Operation".

HINT:

If the transponder key ECU assembly DTC is output simultaneously, troubleshoot the transponder key ECU assembly DTCs first.

PROCEDURE

  1. CLEAR DTC

(a) Clear the DTCs (See page ).

NEXT

  1. CHECK FOR DTC

(a) Perform "DTC Output Confirmation Operation" procedure.

(b) Check for DTCs (See page OK: ).

OK:

DTC B2799*1 or B279986*2 is not output.

  • *1: for 2TR-FE
  • *2: for 2GR-FKS
Result

Result

Proceed to

DTC B2799 is output*1

A

DTC B279986 is output*2

B

Other DTCs are output

C

DTC B2799*1 or B279986*2 is not output

D
  • *1: for 2TR-FE
  • *2: for 2GR-FKS
B

GO TO STEP 11
C

GO TO DIAGNOSTIC TROUBLE CODE CHART
D

USE SIMULATION METHOD TO CHECK
A

  1. INSPECT ECM (TERMINAL IMO)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

*A

for Automatic Transmission

*B

for Manual Transmission

*a

Component with harness connected

(ECM)

*b

Waveform

*c

Approximately 160 ms

*d

Approximately 270 ms

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

E20-9 (IMO) - Body ground

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK:

Waveform is similar to that shown in the illustration.

Result

Result

Proceed to

Normal waveform

A

Terminal IMO stuck low (2.4 V or less)

B

Terminal IMO stuck high (12 V) or abnormal waveform

C
B

GO TO STEP 7
C

GO TO STEP 19
A

  1. INSPECT ECM (TERMINAL IMI)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

*A

for Automatic Transmission

*B

for Manual Transmission

*a

Component with harness connected

(ECM)

*b

Waveform

*c

Approximately 160 ms

*d

Approximately 270 ms

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

E20-10 (IMI) - Body ground

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK:

Waveform is similar to that shown in the illustration.

NG

GO TO STEP 9
OK

  1. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID (See page ).

NEXT

  1. CHECK WHETHER ENGINE STARTS

(a) Using a registered door control transmitter assembly, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)
NG

GO TO STEP 19

  1. INSPECT ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

E20-9 (IMO) - Body ground

Ignition switch turned to ON using registered door control transmitter assembly

Terminal IMO stuck low (2.4 V or less)
Text in Illustration

*a

Front view of wire harness connector

(to ECM)
Result

Result

Proceed to

Terminal IMO stuck low (2.4 V or less)

A

Terminal IMO stuck high (12 V) or abnormal waveform

B
B

GO TO STEP 19
A

  1. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECUASSEMBLY - ECM)

(a) Disconnect the T10 transponder key ECU assembly connector.

(b) Disconnect the E20 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

T10-12 (EFII) - E20-9 (IMO)

Always

Below 1 Ω

T10-12 (EFII) or E20-9 (IMO) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

  1. REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly with a new one (See page ).

NEXT

  1. CHECK WHETHER ENGINE STARTS

(a) Using a registered door control transmitter assembly, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)
NG

REPLACE ECM

  1. INSPECT ECM (TERMINAL IMO)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

*a

Component with harness connected

(ECM)

*b

Waveform

*c

Approximately 160 ms

*d

Approximately 270 ms

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

E14-9 (IMO) - Body ground

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK:

Waveform is similar to that shown in the illustration.

Result

Result

Proceed to

Normal waveform

A

Terminal IMO stuck low (2.4 V or less)

B

Terminal IMO stuck high (12 V) or abnormal waveform

C
B

GO TO STEP 15
C

GO TO STEP 19
A

  1. INSPECT ECM (TERMINAL IMI)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

*a

Component with harness connected

(ECM)

*b

Waveform

*c

Approximately 160 ms

*d

Approximately 270 ms

Measurement Condition:

Tester Connection

Condition

Tool Setting

Specified Condition

E14-8 (IMI) - Body ground

Within 3 seconds of starter operation and initial combustion, or within 3 seconds of ignition switch first being turned to ON after cable disconnected and reconnected to negative (-) battery terminal

2 V/DIV., 500 ms./DIV.

Pulse generation

(See waveform)

OK:

Waveform is similar to that shown in the illustration.

NG

GO TO STEP 17
OK

  1. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID (See page ).

NEXT

  1. CHECK WHETHER ENGINE STARTS

(a) Using a registered door control transmitter assembly, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)
NG

GO TO STEP 19

  1. INSPECT ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

E14-9 (IMO) - Body ground

Ignition switch turned to ON using registered door control transmitter assembly

Terminal IMO stuck low (2.4 V or less)
Text in Illustration

*a

Front view of wire harness connector

(to ECM)
Result

Result

Proceed to

Terminal IMO stuck low (2.4 V or less)

A

Terminal IMO stuck high (12 V) or abnormal waveform

B
B

GO TO STEP 19
A

  1. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECUASSEMBLY - ECM)

(a) Disconnect the T10 transponder key ECU assembly connector.

(b) Disconnect the E14 ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

T10-12 (EFII) - E14-9 (IMO)

Always

Below 1 Ω

T10-12 (EFII) or E14-9 (IMO) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

  1. REPLACE TRANSPONDER KEY ECU ASSEMBLY

(a) Replace the transponder key ECU assembly with a new one (See page ).

NEXT

  1. CHECK WHETHER ENGINE STARTS

(a) Using a registered door control transmitter assembly, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)
NG

REPLACE ECM

  1. REPLACE ECM

(a) Temporarily replace the ECM with a new one (See page ).

NEXT

  1. REGISTER ECU COMMUNICATION ID

(a) Register the ECU communication ID (See page ).

NEXT

  1. CHECK WHETHER ENGINE STARTS

(a) Using a registered door control transmitter assembly, turn the ignition switch to ON.

(b) Check that the engine starts 5 seconds after the ignition switch was turned to ON.

OK:

Engine starts normally.

OK

END (ECM WAS DEFECTIVE)
NG

REPLACE TRANSPONDER KEY ECU ASSEMBLY

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