Last Modified: 4-30-2014 6.6 C Doc ID: RM00000185J000X
Model Year: 2006 Model: LX470 Prod Date Range: [05/2005 -           ]
Title: ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2796,B2798; No Communication in Immobiliser System; 2006 MY LX470 [05/2005 -        ]

DTC

B2796

No Communication in Immobiliser System

DTC

B2798

Communication Malfunction No. 2

DESCRIPTION

This DTC is stored in memory when a key that does not have a transponder chip is inserted or if communication between the key and transponder key ECU is impossible.

DTC No.

DTC Detection Condition

Trouble Area

B2796

No communication

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

B2798

Communication malfunction No. 2

Key

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 (B2796 is stored in memory)

A

All keys start engine

B

Specific key does not start engine (B2796 is stored in memory)

C

B

NO PROBLEM

C

REPLACE SPECIFIC KEY

A

2.

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

T27-8 (VC5) - T11-1 (VC5)

Below 1 Ω

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

T27-12 (TXCT) - T11-5 (TXCT)

T27-13 (AGND) - T11-7 (GND)

T27-8 (VC5) or T11-1 (VC5) - Body ground

10 kΩ or higher

T27-11 (CODE) or T11-4 (CODE) - Body ground

T27-12 (TXCT) or T11-5 (TXCT) - Body ground

T27-13 (AGND) or T11-7 (GND) - Body ground

NG

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK

3.

CHECK OPERATION OF TRANSPONDER KEY AMPLIFIER

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

OK:

Engine starts.

NG

REPLACE TRANSPONDER KEY ECU ASSEMBLY

OK

END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)