B2798

ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2796: No Communication in 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 and transponder key ECU is not possible.






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester on.
(d) Enter the following menus: Body Electrical / Immobiliser / Data List.
(e) According to the display on tester, read the "Data List".

Immobiliser:





OK:
"UNSET" (ignition switch ON) appears on the screen.
NG -- CHECK WHETHER ENGINE STARTS WITH OTHER KEYS
OK -- REPLACE TRANSPONDER KEY ECU ASSEMBLY
2. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS
(a) Check whether the engine starts with the vehicle's other keys.
OK:
Engine starts.
NG -- READ VALUE USING TECHSTREAM
OK -- RE-REGISTER OR REPLACE KEY THAT CANNOT START ENGINE
3. READ VALUE USING TECHSTREAM
(a) Connect a Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the tester on.
(d) Enter the following menus: Body Electrical / Immobiliser / Data List.
(e) According to the display on tester, read the "Data List".

Immobiliser:





OK:
"NORMAL" (antenna coil is normal) appears on the screen.
NG -- REPLACE TRANSPONDER KEY AMPLIFIER
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)




(a) Disconnect the D23 transponder key ECU connector.
(b) Disconnect the D24 transponder key amplifier connector.
(c) Measure the resistance of the wire harness side connectors.
Standard resistance:





(d) Reconnect the D23 transponder key ECU connector.
(e) Reconnect the D24 transponder key amplifier connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. REPLACE 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 DEFECTIVE)