Driving home last night and the check engine light came on. Torque app pulled code P0606 ECM/PCM code and a pending P0137 o2 sensor Circuit Low Voltage Bank 1 Sensor 2 code. History - I've had the P0420 code about a year ago and installed a spacer which fixed that issue. I had installed one of those cheapo aftermarket Cats. I wonder if this is related to the aftermarket Cat going bad. I've read that it's really rare for the ECM to go bad. I'm about to clear the code and I'll test my 12V battery when I get home tonight. Has anyone previously encountered this problem and if so, what was the fix?
Error P0606 indicates a malfunction of the ECM. In addition to the code detected by the program, are there any other signs? Illuminate the MIL? Look at the manual for the detected errors? https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/2054m/cip0604.pdf According to the oxygen sensor trick, it probably still doesn’t work as well as the standard system. https://share.qclt.com/%E4%B8%B0%E7%94%B0%E6%99%AE%E7%91%9E%E6%96%AF%E5%8E%9F%E5%8E%82%E8%8B%B1%E6%96%87%E6%89%8B%E5%86%8Cpdf%E6%A0%BC%E5%BC%8F/repair%20manual/04pruisr/05/2054m/cip0136.pdf
I would look into the P0137 first. I have seen Toyotas set P0606 when there's a problem with one of the air fuel or oxygen sensors. Apparently the ECM can have a hissy fit when the sensors disagree. Posted via the PriusChat mobile app.
That's my thought process too - I replaced the Cat yesterday and I've ordered a new downstream O2 sensor. Then, I'll just wait and see if P0606 returns.
