Toyota Tacoma (2015-2018) Service Manual: Engine Immobiliser System Malfunction (B2799,B279986)

Toyota Tacoma (2015-2018) Service Manual / Engine Immobiliser / Engine Immobiliser System(w/o Smart Key System) / Engine Immobiliser System Malfunction (B2799,B279986)

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

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 Confirmation Operation".

HINT:

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

PROCEDURE

CLEAR DTC

(a) Clear the DTCs (See page ).

2.	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 B27991 or B2799862 is not output	D

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

GO TO STEP 11

GO TO DIAGNOSTIC TROUBLE CODE CHART

USE SIMULATION METHOD TO CHECK

3.	INSPECT ECM (TERMINAL IMO)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

for Automatic Transmission

for Manual Transmission

Component with harness connected

(ECM)

Waveform

Approximately 160 ms

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)

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

GO TO STEP 7

GO TO STEP 19

4.	INSPECT ECM (TERMINAL IMI)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

for Automatic Transmission

for Manual Transmission

Component with harness connected

(ECM)

Waveform

Approximately 160 ms

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)

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.

GO TO STEP 9

5.	REGISTER ECU COMMUNICATION ID

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

6.	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.

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

GO TO STEP 19

7.	INSPECT ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

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

GO TO STEP 19

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

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

(b) Disconnect the E20 ECM connector.

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

9.	REPLACE TRANSPONDER KEY ECU ASSEMBLY

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

10.	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.

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

REPLACE ECM

11.	INSPECT ECM (TERMINAL IMO)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

Component with harness connected

(ECM)

Waveform

Approximately 160 ms

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

GO TO STEP 15

GO TO STEP 19

12.	INSPECT ECM (TERMINAL IMI)

(a) Using an oscilloscope, check the waveform.

Text in Illustration

Component with harness connected

(ECM)

Waveform

Approximately 160 ms

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.

GO TO STEP 17

13.	REGISTER ECU COMMUNICATION ID

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

14.	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.

END (COMMUNICATION ID REGISTRATION WAS DEFECTIVE)

GO TO STEP 19

15.	INSPECT ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the ECM connector.

(b) Turn the ignition switch to ON.

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

GO TO STEP 19

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

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

(b) Disconnect the E14 ECM connector.

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

REPAIR OR REPLACE HARNESS OR CONNECTOR

17.	REPLACE TRANSPONDER KEY ECU ASSEMBLY

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

18.	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.

END (TRANSPONDER KEY ECU ASSEMBLY WAS DEFECTIVE)

REPLACE ECM

19.	REPLACE ECM

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

20.	REGISTER ECU COMMUNICATION ID

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

21.	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.

END (ECM WAS DEFECTIVE)

REPLACE TRANSPONDER KEY ECU ASSEMBLY

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