High Voltage Code???
 

I just purchased my 2010 370 about three weeks ago w/ 11,000 miles on it. I have noticed that the voltage meter has been running about 14v. I thought that seemed a little high but I just kept running it. This weekend a the engine light came on. I took it autozone and they told me it had a code of UO164 which came up as nothing. They told me it was just to new. Upon further research, I believe it probably read PO164 which indicates "02 Sensor Circuit High Voltage (Bank 2 Sensor 3)". Any suggestions on what could be causing this?

If your CEL is still on or comes back on take it to the dealer, thats what your warranty is for. As for the voltage you are seeing its perfectly normally, I usually see over 14volts.

I'm scheduled to take it in Wednesday.

The voltmeter probably has nothing to do with it. 14V is normal though. Probably just an issue with the O2. This code indicates that the heated oxygen sensor reading is too high. Could be shorted out or frayed wire. Could reset it to see if it comes back. But it is under warrenty.

They reset it at autozone and it came back on after about 50 miles of driving. Thanks for the input guys. I had planned on taking it in on warranty but I wanted to know if anyone had heard of it before. I searched the forum but there was not anything similiar to my code. It's good to know the voltage level is normal though.

The error is indicative of a high/low O2 sensor reading. Its measurement is sent as a voltage and that is what your code is indicating is out of bounds. It is unrelated to the gauge on the dash.

As far as the system goes, 14v is normal running. That's the alternator charging the battery. Turn off the engine and a good battery should be noticeably over 12v. With the motor still off run the AC, lights, and stereo and you can watch them drain over about 20 or 30 mins down to 12v. I don't know for our cars and don't want to find out, but the starter should function somewhere below 11v.

Just like AAs, the rating is an average charge held over the lifetime. They will start higher and over time fall below the specified voltage until eventually not pushing sufficient current.

there is a U0164 which is probably what it is as generic scan tools will accurately read the code they just won't have the proper description U0164 indicates CAN line communication failure between the ecu and the combination meter take it to the dealership.