B2798
ENGINE IMMOBILISER: ENGINE IMMOBILISER SYSTEM: B2796, B2798: No Communication in Immobiliser System
B2798 - Communication Malfunction No. 2
DESCRIPTION
* DTC B2796 is output when a key is inserted into the ignition key cylinder but no communication occurs between the key and transponder key ECU.
* DTC B2798 is output when a key is inserted into the ignition key cylinder but a communication error occurs between the key and transponder key ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT
When the transponder key ECU is replaced, reregister the ECU - ECM communication ID Engine Immobiliser System.
PROCEDURE
1. CLEAR DTC
(a) Clear the DTC Engine Immobiliser System.
NEXT -- Continue to next step.
2. CHECK FOR DTC
(a) Check for DTC Engine Immobiliser System.
OK:
DTC B2796 or B2798 is not output.
NG -- READ VALUE USING TECHSTREAM (ENGINE IMMOBILISER SYSTEM)
OK -- USE SIMULATION METHOD TO CHECK How To Proceed With Troubleshooting
3. READ VALUE USING TECHSTREAM (ENGINE IMMOBILISER SYSTEM)
(a) Use the Data List to check if the engine immobiliser system is functioning properly.
Immobiliser
OK:
Unset (key is in ignition key cylinder) appears on the screen.
NG -- CHECK WHETHER ENGINE STARTS WITH OTHER KEYS
OK -- REPLACE TRANSPONDER KEY ECU Removal
4. CHECK WHETHER ENGINE STARTS WITH OTHER KEYS
(a) Check if the engine starts with an already registered vehicle key.
OK:
Engine starts.
NG -- CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)
OK -- REREGISTER KEY CODE OR REPLACE KEY THAT CANNOT START ENGINE
5. CHECK HARNESS AND CONNECTOR (TRANSPONDER KEY ECU - TRANSPONDER KEY AMPLIFIER)
(a) Disconnect the J26 ECU connector.
(b) Disconnect the J20 amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. REPLACE TRANSPONDER KEY AMPLIFIER
(a) Temporarily replace the transponder key amplifier with a new or normally functioning one Removal.
NEXT -- Continue to next step.
7. CHECK WHETHER ENGINE STARTS
(a) Check that the engine starts normally.
OK:
Engine starts normally.
NG -- REPLACE TRANSPONDER KEY ECU Removal
OK -- END (TRANSPONDER KEY AMPLIFIER IS DEFECTIVE)