DTC 4

DTC 4 (FOUR) "CODE 4. ECU FAILURE"

CIRCUIT DESCRIPTION

DTC Detection Condition:

The telephone ECU assy (mayday ECU) is provided under the rear seat no.1 and determines the vehicle operating conditions, vehicle position and user requirements based on the information provided by various constituent parts and controls the LEXUS link system.

INSPECTION PROCEDURE

REPLACE TELEPHONE ECU ASSY (MAYDAY ECU)

HINT: If DTC is not cleared even when the mayday ECU assy is replaced, replace the mayday assy (transceiver, portable phone-L battery (back-up battery), bus buffer ECU and mayday ECU).