HELLO,
MY 04 QC 4.7 THROUGH CODE P0038 THE OTHER DAY I FOUND OUT ITS AN OXYGEN SENSOR HIGH VOLTAGE READING. I AM GUESSING THIS MEANS THE O2 SENSORS NEED REPLACEMENT? IF SO CAN SOMEONE ADVISE ON HOW MANY AND LOCATIONS? I WILL DO A SEARCH NOW.
THANKS!

 

Well, I know that this code is a "Bank 1, Sensor 2" code which is that if you have a 4 sensor system, it will be on the left (driver) side and it will be the sensor after the Catalytic Converter. If you only have 2 sensors, which is common, you don't have to worry about the left side part, it is just the one after your cat.

Hope this helps a little.

 

Thank you very much!! That was exactly the info I was looking for. I didn't want to replace all four sensors if only one is bad.
Thanks again

 

I had the same code on a two sensor configuration and replaced the downstream sensor. Drove it for a while and it did not reset so I tried the :remove the battery terminal and turn the key to start" to clear. On restart it appeared the code was clear for a second then came back on - same code. Any idea what/why this is happening? Thanks

 

What brand of sensor did you use? Wow, this thread is 13 years old...lol

 

Bosch

 

There's part of the problem....... Our trucks don't like Bosch sensors. At all. NTK, or Denso please.

Although, that code is for Heater control circuit high.... Not sure how that could even happen......

 

I'm not following you. I'll try another brand but am not sure what you mean by the rest. I'm a novice at big issue repairs and this one has me stumped.

 

The bosch sensors are inaccurate, and apparently, react too slow for the dodge PCM to be happy with them, you want an NTK or Denso brand O2 sensor.

The code you are getting is whining about high voltage on the Heater circuit. Considering the heater is supposed to get system voltage (12 volts, or, whatever the alternator is putting out), I am not entirely sure just how the PCM determines that voltage is 'too high'..... Unless it is seeing voltage on the circuit, when it doesn't think there should be any. A lot depends on how the heater in the sensor is powered, does it have a 12 volt feed, and the PCM grounds the circuit, or, does the PCM control a relay, that feeds power to the heater circuit......

The code refers specifically to bank 1, sensor 2. That's going to be the sensor AFTER the catalytic converter. (and I suspect there will only be one... if you have two cats, the code would be referring to the sensor on the drivers side bank.) If you haven't replaced that sensor yet, go ahead and swap it out. See if that solves it.

 

I swapped it out for a Denso and the light did not clear. Bought an OBD reader and it will not connect for diagnostics (it did connect properly on another vehicle). Tried both the negative and then positive battery cables but it did not clear the code. I'd really like the light to go out!