B2798

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2796,B2798: No Communication in Immobiliser System
B2798 - Communication Malfunction No. 2

DESCRIPTION

When a key is inserted into the ignition key cylinder but no communication occurs between the key and transponder key ECU assembly, DTC B2796 is output. When a key is inserted into the ignition key cylinder but a communication error occurs between the key and transponder key ECU assembly, DTC B2798 is output.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (ENGINE IMMOBILISER SYSTEM)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON with the key that cannot start the engine.

(c) On the Techstream enter the following menus: Body Electrical / Immobiliser / Data List / Immobiliser. Read the values.

Immobiliser





OK:

"Unset" (ignition switch ON) appears on the screen.

OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY Removal
NG -- Continue to next step.

2. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS

(a) Check whether the engine starts with the vehicle's other keys.

OK:

Engine starts.

OK -- RE- REGISTER OR REPLACE KEY THAT CANNOT START ENGINE
NG -- Continue to next step.

3. READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch ON with the key that will not start the engine.

(c) On the Techstream, enter the following menus: Body Electrical / Immobiliser / Data List / Antenna Coil Status. Read the values.

Immobiliser





OK:

"Normal" (transponder key coil is normal) appears on screen.

OK -- REPLACE TRANSPONDER KEY AMPLIFIER
NG -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY AMPLIFIER)

(a) Disconnect the T10 ECU connector.





(b) Disconnect the T9 amplifier connector.

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

Standard resistance:





(d) Reconnect the ECU connector.

(e) Reconnect the amplifier connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

5. REPLACE TRANSPONDER KEY AMPLIFIER (OPERATION)

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

OK:

Engine starts.

NG -- REPLACE TRANSPONDER KEY ECU ASSEMBLY Removal

OK -- NORMAL (TRANSPONDER KEY AMPLIFIER DEFECTIVE)