Toyota CH-R Service Manual: Engine Immobiliser System Malfunction (B2799)

Toyota CH-R Service Manual / Theft Deterrent / Keyless Entry / Immobiliser System(w/o Smart Key System) / Engine Immobiliser System Malfunction (B2799)

DESCRIPTION

The ECM stores this DTC when the communication line between the ECM and transponder key ECU assembly is malfunctioning or the communication ID of the ECM and transponder key ECU assembly do not match.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Note
B2799	Engine Immobiliser System Malfunction	Either condition is met (1 trip detection logic*2): A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly. A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.	Wire harness or connector Transponder key ECU assembly ECM	DTC Output Confirmation Operation: Start the engine and wait 10 seconds.1 After disconnecting and reconnecting the cable to the negative (-) battery terminal, turn the ignition switch to ON and wait 10 seconds.2 1: Communication starts within 3 seconds of starting the engine. If verification fails, this DTC is stored 6 seconds after communication has completed. 2: Communication starts within 3 seconds of turning the ignition switch to ON. If verification fails, this DTC is stored 6 seconds after communication has completed.

DTC Detection Conditions

		Vehicle Condition
		Pattern 1	Pattern 2
Diagnosis Condition	Engine start operation.	○	○
Malfunction Status	A malfunction occurs in the communication or communication lines between the ECM and transponder key ECU assembly.	○	-
Malfunction Status	A communication code cannot be verified during communication between the ECM and transponder key ECU assembly.	-	○
Detection Time		-	-
Number of Trips		1 trip	1 trip

HINT:

DTC will be output when conditions for either of the patterns in the table above are met.

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	-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

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

HINT:

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

PROCEDURE

CLEAR DTC

(a) Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs

2.	CHECK FOR DTC

(a) Start the engine.

(b) Check for DTCs.

Powertrain > Engine and ECT > Trouble Codes

HINT:

Before checking for DTCs, perform the "DTC Output Confirmation Operation" procedure.

OK:

B2799 is not output.

Result	Proceed to
OK	A
NG (DTC B2799 is output)	B
NG (Other DTCs are output)	C

USE SIMULATION METHOD TO CHECK

GO TO DIAGNOSTIC TROUBLE CODE CHART

3.	INSPECT ECM (TERMINAL IMO)

(a) Using an oscilloscope, check the waveform

Component with harness connected

(ECM)

Waveform

Measurement Condition

Item	Content
Tester Connection	A38-45 (IMO) - Body ground
Tool Setting	2 V/DIV., 500 ms./DIV.
Condition	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

Result	Proceed to
OK	A
NG (Terminal IMO stuck low (2.4 V or less))	B
NG (Terminal IMO stuck high (12 V) or abnormal waveform)	C

GO TO STEP 10

GO TO STEP 7

4.	INSPECT ECM (TERMINAL IMI)

(a) Using an oscilloscope, check the waveform

Component with harness connected

(ECM)

Waveform

Measurement Condition

Item	Content
Tester Connection	A38-28 (IMI) - Body ground
Tool Setting	2 V/DIV., 500 ms./DIV.
Condition	Ignition switch ON

OK:

Waveform is similar to that shown in the illustration.

Result	Proceed to
OK	A
NG	B

GO TO STEP 12

5.	REGISTER ECU COMMUNICATION ID

(a) Reregister the ECU communication ID.

HINT:

Refer to Registration.

Click here

6.	CHECK WHETHER ENGINE STARTS

(a) Using a registered key, 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)

7.	REPLACE ECM

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

Click here

8.	REGISTER ECU COMMUNICATION ID

(a) Reregister the ECU communication ID.

HINT:

Refer to Registration.

9.	CHECK WHETHER ENGINE STARTS

(a) Using a registered key, 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

10.	INSPECT ECM (IMO TERMINAL VOLTAGE)

(a) Disconnect the A38 ECM connector

(b) Turn the ignition switch to ON

Standard Voltage:

Tester Connection	Condition	Result
A38-45 (IMO) - Body ground	Ignition switch turned to ON using registered key	Terminal IMO stuck low (2.4 V or less)
A38-45 (IMO) - Body ground	Ignition switch turned to ON using registered key	Terminal IMO stuck high (12 V) or Abnormal waveform

*a	Front view of wire harness connector (to ECM)

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 7

11.	CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - ECM AND BODY GROUND)

(a) Disconnect the F22 transponder key ECU assembly connector

(b) Disconnect the A38 ECM connector

Standard Resistance:

Tester Connection	Condition	Specified Condition
F22-12 (EFII) - A38-45 (IMO)	Always	Below 1 Ω
A38-45 (IMO) - Body ground	Always	10 kΩ or higher
F22-12 (EFII) - Body ground	Always	10 kΩ or higher
F22-13 (EFIO) - A38-28 (IMI)	Always	Below 1 Ω
A38-28 (IMI) - Body ground	Always	10 kΩ or higher
F22-13 (EFIO) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

12.	REPLACE TRANSPONDER KEY ECU ASSEMBLY

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

Click here

HINT:

Refer to Registration.

Click here

NOTICE:

Key ID code registration is necessary when replacing the transponder key ECU assembly.

Click here

13.	CHECK WHETHER ENGINE STARTS

(a) Using a registered key, 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

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