Theft Deterrent System Communication Line High Fixation (B279A)

DESCRIPTION

If the communication line (EFIO - IMI) to the certification ECU (smart key ECU assembly) is stuck high output (e.g. shorted to +B), the ECM stores this DTC.

DTC No.	DTC Detection Condition	Trouble Area
B279A	When the communication line (EFIO - IMI) between ECM and certification ECU (smart key ECU assembly) is stuck high output.	Wire harness or connector Certification ECU (Smart key ECU assembly) ECM

WIRING DIAGRAM
CAUTION / NOTICE / HINT

NOTICE:

If the certification ECU (smart key ECU assembly) is replaced, register the key (See page ).

PROCEDURE

1. CHECK DTC OUTPUT

(a) Clear the DTCs (See page ).

(b) Recheck for DTCs (See page ).

HINT:

If any DTCs other than DTC B279A are output, troubleshoot those DTCs first.

Result	Proceed to
DTC B279A is output	A
DTC B279A and other DTCs are output	B

B

GO TO DIAGNOSTIC TROUBLE CODE CHART

A

1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - ECM)

(a) Disconnect the certification ECU (smart key ECU assembly) connector.

(b) Disconnect the ECM connector.

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

Standard Resistance:

for 2GR-FE

Tester Connection	Condition	Specified Condition
D25-35 (EFIO) - A41-40 (IMI)	Always	Below 1 Ω
D25-35 (EFIO) - Body ground	Always	10 kΩ or higher

for 1AR-FE

Tester Connection	Condition	Specified Condition
D25-35 (EFIO) - A49-11 (IMI)	Always	Below 1 Ω
D25-35 (EFIO) - Body ground	Always	10 kΩ or higher

Standard Voltage:

Tester Connection	Condition	Specified Condition
D25-35 (EFIO) - Body ground	Always	Below 1 V

Text in Illustration

*1	Front view of wire harness connector (to Certification ECU (Smart Key ECU Assembly))
*2	Front view of wire harness connector (to ECM)
*3	for 2GR-FE
*4	for 1AR-FE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

1. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Reconnect the certification ECU (smart key ECU assembly) connector.

(b) Reconnect the ECM connector.

(c) Using an oscilloscope, check the waveform.

Waveform (Reference):

Item	Content
Terminal No. (Symbol)	D25-35 (EFIO) - D25-15 (E)
Tool Setting	5 V/DIV., 100 msec./DIV.
Condition	Engine switch on (IG)

OK:

Waveform is output normally (see illustration).

Result	Proceed to
NG	A
OK (for 2GR-FE)	B
OK (for 1AR-FE)	C

Text in Illustration

*1	Component with harness connected (Certification ECU (Smart Key ECU Assembly))
*2	GND

B

REPLACE ECM

C

REPLACE ECM

A

1. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Replace the certification ECU (smart key ECU assembly) (See page ).

NEXT

1. KEY REGISTRATION

(a) Register the key (See page ).

NEXT

1. REGISTER ECU COMMUNICATION ID

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

NEXT

1. CHECK DTC OUTPUT

(a) Clear the DTCs (See page ).

(b) Recheck for DTCs (See page ).

OK:

DTC B279A is not output.

Result	Proceed to
OK	A
NG (for 2GR-FE)	B
NG (for 1AR-FE)	C

A

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)

B

REPLACE ECM

C

REPLACE ECM