I recently bought a 2006 dodge dakota 3.7 v6 2wd. it has 6 codes currently. 4 of them are for all 4 o2 sensors having bad heating circuits, P0031, P0037, P0051 and P0057. The other two are for closed loop fueling not achieved, which are codes P1129 and P1128. Another problem this truck has is that the temperature gauge doesn’t work, and the coolant temperature light is on. the truck DOESNT overheat, i’ve driven it for long periods with absolutely no issues. Now the first thing i’m assuming is that the closed loop fueling issues are related to the O2 sensors, and i know for sure that each O2 sensor is not individually needing to be replaced, because i replaced one and the codes are still up. I checked the fuse and relays just in case, but like i expected none of them were bad. I then replaced the coolant temperature sensors sensor thinking that would get rid of the temperature problem, but it didn’t. the wire to the coolant temp sensor also has a good ground and good power. Now i’m just completely lost, because i have no clue what the issue here could be. I’m assuming it has something to do with the PCM, but i also am hesitant of that idea because other than the issues mentioned the truck drives, idles, and operates perfectly fine. I would appreciate anyone’s help on this matter as i’ve already wasted too much money and time on things that did absolutely nothing. Thank you

 

Need to look at the heater circuit, there is likely a fuse, and relay......

 

I mean i opened the fuse box the one under the hood i forgot what that ones called.. but i looked through every fuse and none of them mentioned o2 sensors, heater circuit, nothing like that. Maybe it’s some different name but i also did some research and couldn’t find a fuse or relay for the heater circuit

 

Check fuse #67 - Heating ventilation air conditioning relay

And click HERE for alink to the 2005 Dodge Dakota Factory Service Manual , FREE!
Welcome aboard.

 

Will check that when i’m home, thank you for the help. I’ll post an update in a couple hours

 

i checked the fuse and it’s in good condition. Are there any simple easy things i can check before i start messing with the pcm or grounding points?