DTC P0606 ECM / PCM Processor: Description

WARNING: This page is about a different car, the 2008 Toyota Yaris. 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 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 DETECTION CONDITIONS CHART

DTC No.	DTC Detection Conditions	Trouble Areas
P0606	When one of following conditions is met: ECM CPUs malfunction Air-Fuel Ratio (A/F) sensor transistors built into ECM malfunctions Heated Oxygen (HO2) sensor transistors built into ECM malfunctions	Exhaust gas leak HO2 sensor ECM

NOTE: First check for an exhaust gas leak around the HO2 sensor if P0606 is present. An exhaust gas leak generates noise in the HO2 sensor output. The ECM may interpret this as an HO2 sensor transistor malfunction and set P0606.