Question P0340 CMP Sensor & P0102 MAF

[usererror]

Looks like the fuse for ENG-1 blew again after two days. After some searching some people had this happen when an O2 sensor was going bad.

How many are there? I am going to get a repair manual for the truck. I figure I can unplug them, one at a time until we find the offending one.

 

[SunlitComet]

4 but other things run off that fuse as well.

---------- Post added at 01:38 PM ---------- Previous post was at 01:36 PM ----------

Start with a ohms test between the pink and black wire of each one.

 

[Sellncars]

The first thing to look for is the fuses under the hood. Did #15 ENG 1 fuse blow? My fuse would keep on blowing and setting these codes, after hours of unhooking things and changing fuses, i found the 02 Sensor after the cat had 3 out of 4 wires broken and touching the body. Salvage yard and a new 02 harness going to the 02 sensor and all is well now. Check your wires.

 

[SunlitComet]

The first thing to look for is the fuses under the hood. Did #15 ENG 1 fuse blow? My fuse would keep on blowing and setting these codes, after hours of unhooking things and changing fuses, i found the 02 Sensor after the cat had 3 out of 4 wires broken and touching the body. Salvage yard and a new 02 harness going to the 02 sensor and all is well now. Check your wires.

Sellncars, Did you seriously not read the whole thread before posting a response?

 

[Sellncars]

Sellncars, Did you seriously not read the whole thread before posting a response?

No, i didn't read every single response. If i want to leave a response, i will do just that. If for some reason you have to read one more reply, then just don't read it. Look that was SIMPLE!!!!

 

[SunlitComet]

If you say so.

 

[usererror]

Thanks, Is this one of the 4 O2 sensors by chance? I do not believe ENG-15 is blown, but I will have to check. I did notice that ENG-1 runs several different items, I have also seen a few other posts related to ENG-1 blowing being connected to a failing heated O2 sensor. When ENG-1 is not blown the Yukon runs great, no other codes, but if ENG-1 is blown then it all goes to hell.

 

[BattelWagun]

That is actually your coolant temperature sender for the gauge cluster. Our trucks have 2, one there thats specifically for the cluster, and another one on the radiator hose on top of the manifold that gives a readout to the PCM.

Your O2 sensors are under the truck, you're gonna have to get it up in the air and crawl under there, there should be 2 before the cats, and 2 after. I know two ofe these are required for proper ECU function so if one is shorted out or something, its just contributing to the problem.

 

[usererror]

Your O2 sensors are under the truck, you're gonna have to get it up in the air and crawl under there, there should be 2 before the cats, and 2 after. I know two ofe these are required for proper ECU function so if one is shorted out or something, its just contributing to the problem.

Thank you, will let you know what I find when I get under there. For now we have 10 spare 20amp fuses in the cup holders!!

 

[SunlitComet]

Thanks, Is this one of the 4 O2 sensors by chance? I do not believe ENG-15 is blown, but I will have to check. I did notice that ENG-1 runs several different items, I have also seen a few other posts related to ENG-1 blowing being connected to a failing heated O2 sensor. When ENG-1 is not blown the Yukon runs great, no other codes, but if ENG-1 is blown then it all goes to hell.

As I mentioned in the photo before that ENG -1 also feeds the MAF and Camshaft sensor so it will definitely go to hell when it blows. As Battlewagun pointed out your picture is the sender for the dash temperature gauge. Get under neath the vehicle and look at the exhaust pipes. You will find one on each pipe up near the engine just behind the exhaust manifolds of the engine you will find another one on each pipe after thew catalytic converters. There are little metal boxes covering the connectors for the rear sensors and the are mounted to either frame rail with one bolt. Also there is no ENG-15 fuse so don't go nuts looking for it.