DTC P0116: Engine Coolant Temperature (ECT) Circuit Range/Performance Fault Or DTC P0125: Insufficient Coolant Temperature For Closed Loop Fuel Control: Notes

WARNING: This page is about a different car, the 2003 Lexus GS 430. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For information on engine immobilizer system, see COMPUTERIZED ENGINE CONTROLS in THEORY & OPERATION article.

CAUTION: If ECM replacement is instructed in following testing, always ensure ECM harness connector and ground circuit are okay. If either are suspect, repair and repeat testing to confirm ECM malfunction. If ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES - LEXUS article.