THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM: DESCRIPTION (2008 LX570)

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Last Modified: 11-27-2007		1.6 C
Service Category: Vehicle Interior	Section: Theft Deterrent/Keyless Entry
Model Year: 2008	Model: LX570	Doc ID: RM000002UBW008X
Title: THEFT DETERRENT / KEYLESS ENTRY: ENGINE IMMOBILISER SYSTEM: DESCRIPTION (2008 LX570)

DTC

B279A

Theft Deterrent System Communication Line High Fixation

DESCRIPTION

If the communication line (EFIO-IMI) to the ID code box (immobiliser code ECU) is stuck on HI output, the ECM outputs this DTC.

DTC Code	DTC Detection Condition	Trouble Area
B279A	When the communication line (EFIO-IMI) between the ECM and the ID code box (immobiliser code ECU) is stuck on HI output.	Harness or connector ID code box (immobiliser code ECU) ECM

CLEAR DTC

2.	CHECK FOR DTC

HINT:

If 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

3.	CHECK HARNESS AND CONNECTOR (ID CODE BOX - ECM)

(a) Disconnect the E28 box connector.

(b) Disconnect the A38 ECM connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
E28-6 (EFIO) - A38-40 (IMI)	Always	Below 1 Ω
E28-6 (EFIO) or A38-40 (IMI) - Body ground	Always	10 kΩ or higher

Standard Voltage:

Tester Connection	Condition	Specified Condition
E28-6 (EFIO) - Body ground	Always	Below 1 V
A38-40 (IMI) - Body ground	Always	Below 1 V

4.	CHECK ID CODE BOX (IMMOBILISER CODE ECU) (OUTPUT)

(a) Using an oscilloscope, check the waveform.

OK:

Waveform is output normally (See illustration).

5.	CHECK ID CODE BOX (POWER SOURCE AND BODY GROUND)

(a) Turn the engine switch on (IG).

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

Standard Voltage:

Tester Connector	Condition	Specified Condition
E28-1 (+B) - E28-8 (GND)	Always	11 to 14 V