I think I finally found the problem with my truck. It's been in the shop many time's for loss of power, along with many other thing's they could never figure out. This last time it left me stranded on the side of the road. Got it towed to the dealer, and they said it was showing the code for the cam positioning sensor.(041) They said there were 18 other's present as well. They said it was fixed and sent me back out on the road. Fourty mile's later it did it again. Luckily I made it to the next town. I called the local dealer and told him it was spark knocking real bad, and the other dealer had all ready change 2 cam sensor's. He said they have had a lot of truck's with my same problem. He said look at the wire going to the a/c sensore. It could be rubbing on the high pressure line. I looked, and sure enough, there it was. A bare spot rubbed through. I made it to his shop, he taped it up and put a wire loom over it. Now my truck runs better than it ever has.

So, everybody crawl under you truck and see if your wire is rubbing.

 

Thanks for the post and heads up. Any way possible you might could stick a photo up for where to look and what to look for.
Thanks.

 

Glad you got it figured out. Oh & congrats on the truck of the month.

 

A pic would be awesome, no idea which wire you're talking about and not ashamed to admit it

 

I can assure you it wasn't spark knocking.

Just messing with you-I'm glad you got it figured out.

 

I'll try to crawl under there when I get back from Chicago. Getting a camera under there might be a tough job, but I will try.

 

Yikes!

I will be checking out my wires soon after reading this.

Ow, and the picture will help me as well

Thanks for the heads up!

 

I don"t see how a power wire going to the Air Conditioning compresser would cause the truck to run bad. I would think it would just blow the fuse.

 

Some sensors use a 5 or 8 volt power supply which originates at the PCM or ECM and is shared by several sensors. If this voltage is compromised, it can bring down the whole system, or cause goofy sensor inputs. It often can't/won't blow a fuse because there is no fuse on the output side of the processor, and the amperage isn't high enough to blow a 12V power feed fuse on the input side.

 

From the schematics it appears the A/C pressure transducer share the same power signals with the camshaft sensor.

MikeyB

 

Bingo!! That's exactly what the dealer told me. He said they discovered the problem by DC asking why they were replacing all these sensor's that in the long run tested good. So after day's of diagnosing, they discovered the shorted wire. Then everytime they had a truck in with similar symtom's, that's the first thing they checked, and found many with that problem. All's I know is I pulled the wire away and my truck was instantly cured. Halaulua

 

So where is this infamous wire located? Is it anywhere near the AC compressor? Thanks!

 

Thank you !

This is just another of many stupid things that go wrong with our trucks that may be helped by reading these forums thanks again!

I'll be checking mine tomorrow!

Rick

 

pict or diagram please. thanks.

 

I had this same problem on my truck back in July, only it "fixed" itself and wouldn't reproduce when at the dealer. Despite a laundry list of codes, the dealer insisted it was bad fuel, probably water (that somehow was only bad for a few minutes). Someone else on the TDR reported a similar problem so I went looking at the wires by the AC compressor. After unwrapping the electical tape on the harness going to the AC refrigerant pressure sensor (3 wire bundle) I found:



two spots where the +5 volt line (pink w/ yellow tracer) had been rubbing against the AC compressor. I could just see where the insulation had just barely been worn through to contact the wires and short out the PCM +5 volt supply.

The big connector in the picture is the 2 pin that controlls the AC clutch. The wires in question do NOT go to this connector, but a 4 place connector (only 3 terminals are used) just off the bottom of the picture. For reference, this shot is under the truck, looking upwards. The blurry white round thing is the oil filter, and the silver unit is the AC compressor. I had both AC related connectors disconnected as it freed up the harness to work on and repair.