Last Modified: 4-30-2014 6.6 C Doc ID: RM00000185K000X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2797; Communication Malfunction No. 1; 2006 MY LX470 [05/2005 -        ]

DTC

B2797

Communication Malfunction No. 1

DESCRIPTION

This DTC is detected when an error occurs, although the communication is performed normally (example: Some noise is included in communication line).

DTC No.

DTC Detection Condition

Trouble Area

B2797

Communication error
  • Key
  • Wire harness
  • Transponder key amplifier
  • Transponder key ECU assembly

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

DELETE DTC AND INSERT ALL PRESENTLY AVAILABLE KEYS TO CHECK WHETHER ENGINE STARTS OR NOT

(a) Delete the DTC 2006 MY LX470 [05/2005 -        ]; ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: DTC CHECK / CLEAR .

(b) Insert all the presently available keys to check whether the engine starts or not.

Result:

Result

Proceed to

All keys do not start engine (B2797 is stored in memory)

A

All keys start engine

B

Specific key does not start engine (B2797 is stored in memory)

C
B

NO PROBLEM

C

REPLACE SPECIFIC KEY

A

2.

CHECK NOISE

(a) Using an oscilloscope or the intelligent tester, check for noise in the waveform between the terminals of the T11 amplifier connector and T27 ECU connector.

OK:

No noise is present (see illustration).

Tester Connection

Tool Setting

Condition

Specified Condition

T27-11 (CODE) - T11-4 (CODE)

5 V/DIV., 20 msec./DIV.

Key inserted

No noise is present
NG

FIND CAUSE OF NOISE AND REMOVE IT

OK

3.

CHECK WIRE HARNESS (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY AMPLIFIER)

(a) Disconnect the T27 ECU connector.

(b) Disconnect the T11 amplifier connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:

Tester Connection

Specified Condition

T27-11 (CODE) - T11-4 (CODE)

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

4.

CHECK OPERATION TRANSPONDER KEY AMPLIFIER

(a) After replacing the transponder key amplifier with a normally functioning transponder key amplifier, check that the engine starts.

OK:

Engine starts.

NG

REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK

END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)