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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.
(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
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
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Last edited by 05dram1500; 04-20-2009 at 10:43 PM..
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???
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.
2005 Dodge Ram 1500 Sport Flame Red 4X4 Quadcab
Herculiner, Extang Tonneau,Front Tow Hooks, Sirius
Tinted Windows 5% rear, 20% front, Cooper Zeon LTZ
Flowmaster single in, dual out, Chrome tips. HEMI
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