Hey whats up guys...im having a huge issue..this code P0158 on my 2005 Dodge Ram 1500 SLT 4x4 5.7L Hemi

P0158-O2 SENSOR 2/2 CIRCUIT HIGH
When Monitored: O2 Sensor Heater Temperature is greater than 496°C (925°F) and battery voltage greater than 10.99 volts.
Set Condition: The Oxygen Sensor voltage is above 3.7 volts for 30 seconds. One Trip Fault. Three good trips to turn off the MIL.
Possible Causes:
(K243) O22/2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE
(K904) O2 DOWNSTREAM RETURN CIRCUIT SHORTED TO BATTERY VOLTAGE
(K243) O2 2/2 SIGNAL CIRCUIT OPEN
(K904) O2 DOWNSTREAM RETURN CIRCUIT OPEN
O2 SENSOR
PCM


Now I got a Diagnostic flow chart and followed it to a "T" as well as calling my Uncle who is an ASE Tech and owns his own shop. He lead me through the process when I got stuck. Now I have 4.17V as my signal voltage (Black wire @ O2S but Brown @ PCM) it says I need less than 3.99V. Anyways.....I unplug just the wire from the PCM and it read 0V as it should bc it is not connected AND if it was shorted it would still read a voltage. now i checked the wire where i could see it and could not see a short on the wire...I also checked the resistance of it and found the wire to be good with no Open spots.

Now could this be the worst possible case...the cause is a short in the PCM. Or have one of you guys had this issue in the past and fixed it without replacing the PCM???


Sorry for the long post....tried to be as descriptive as possible

 

If it is not the sensor or the wires what else could it be? You Ohmed everything out right? If there is no resistance outside the PCM it leads me to believe its inside the PCM. You said that there were no opens in the wires but what were the resitance values? Did you Megger the wires as well to check for voltage leaks???

 

very true...im just trying to see if the could possibly be a seperate issue...but of course its doesnt look good

 

Check out www.car-part.com I found a PCM for an 05 Dodge Ram diesel for 80 bucks at a salvage yard. You never know you may get lucky...

 

ok well now i just noticed the different computer s/n's now would that be on the sticker that is on the PCM or would it be stamped into the PCM???

 

The one I just bought is just on the sticker...

 

ok well i really appreciate the help Alpheus Im glad i got someones second opinion

 

did you ever resolve this issue? if so how. I am getting the same code as of late.... and it is bugging the crap out of me. It doesn't seem to be effecting the performance. And the check engine light goes on and off.

 

Yea I ended up getting a used PCM out of a junk yard and having the dealer put it in bc they need to flash the module so it will work with your exact truck. I mean the PCM may not be your issue but then again its always a possiblity. But i will say....make sure the PCM is your last resort. do everything you can to diagnose the issue and then if all else fails go to the PCM