P1645

DTC P1645 GATEWAY ECU MALFUNCTION

CIRCUIT DESCRIPTION

DTC Detection Condition:

ECM receives the operating condition (ON/OFF) of A/C from A/C ECU and it also receives the electrical load information from the Gateway ECU.

ECM uses these information to control the engine (idle up, etc.).

INSPECTION PROCEDURE
Perform troubleshooting the Body Multiplex Communication System.

HINT: Read freeze frame data using LEXUS hand-held tester or OBD II scan tool. Because freeze frame records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.