Monitor Description

The ECM (included in the hybrid vehicle control ECU) continuously monitors its internal processors (CPUs), air fuel ratio sensor transistors and heated oxygen (HO2) sensor transistors built into the ECM. 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 TROUBLE DETECTION CONDITION CHART

DTC No.	DTC Detection Condition	Trouble Area
P0607	When one of following conditions is met: Hybrid vehicle control ECU CPUs malfunction Air fuel ratio sensor transistors built into hybrid vehicle control ECU malfunctions Heated oxygen transistors built into hybrid vehicle control ECU malfunctions	Exhaust gas leak Heated oxygen sensor Hybrid vehicle control ECU

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.