B2798

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM:

DTC B2796 - No Communication in Immobiliser System

DTC B2798 - Communication Malfunction No. 2

DESCRIPTION

This DTC is output when a key that does not have a transponder chip is inserted into the ignition key cylinder or if communication between the key, transponder key amplifier and transponder key ECU is not possible.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (IMMOBILISER SYSTEM)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Immobiliser / Data List.
(e) Read the Data List according to the display on the Techstream.

Immobiliser (Transponder key ECU assembly)





OK:
On the Techstream screen, the item changes between UNSET and SET according to the chart above.
OK -- READ VALUE USING TECHSTREAM (TRANSPONDER KEY COIL)
NG -- Continue to next step.
2. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS
(a) Check if the engine starts with the vehicle's other keys.
OK:
Engine starts.
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG -- Continue to next step.
3. READ VALUE USING TECHSTREAM (TRANSPONDER KEY COIL)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / Immobiliser / Data List.
(e) Read the Data List according to the display on the Techstream.

Immobiliser (Transponder key ECU assembly)





OK:
On the Techstream screen, the item displays Normal according to the chart above.
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
NG -- Continue to next step.
4. CHECK WIRE HARNESS (TRANSPONDER KEY ECU ASSEMBLY - TRANSPONDER KEY AMPLIFIER)




(a) Disconnect the T8 ECU connector.
(b) Disconnect the T7 amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS AND CONNECTOR
OK -- Continue to next step.
5. CHECK OPERATION OF 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 DEFECTIVE)