Monitor Description

WARNING: This page is about a different car, the 2008 Toyota FJ Cruiser. However, it is still accessible from the selected car via links, so may be relevant.

The ECM continuously monitors its internal processors (CPUs), Air Fuel Ratio (A/F) sensor transistors and Heated Oxygen (HO2) sensor transistors. This self-check ensures that the ECM is functioning properly. This is diagnosed by internal "mirroring" of the main and sub CPUs to detect processor errors. If outputs from the processors deviate from the standards, the ECM will illuminate the MIL and set the DTC immediately.

DTC DETECTION CONDITION

DTC No.	DTC Detection Condition	Trouble Area
P0607	When one of following conditions is met: ECM CPUs malfunction Air Fuel Ratio (A/F) sensor transistors built into ECM malfunctions Heated Oxygen (HO2) transistors built into ECM malfunctions	Exhaust gas leak HO2 sensor ECM
P0607	For Mexico models: ECM CPU error	ECM

NOTE: An exhaust gas leak generates noise in the HO2 sensor output. The ECM may interpret this as an HO2 sensor transistor malfunction and set P0607.