Dead 05 LLY EGR problems overheating ect..

I have a friend with a 05 LLY who told me and I quote " The truck has had erratic cooling for some time and I know it has EGR issues but I havent got around to fixing it"
He was driving home a few weeks ago and the truck overheated and he pulled over. The truck died and he could not restart it. He towed it to my place and asked me if I would be willing to look at it. I said yes but I know nothing about the Duramax engine.
The truck sat here for a while and by the time I got into the shop the batteries were dead. I put new batteries in it and tried to read codes but I cannot get power from the OBD2 port. I tried my INNOVA 3140 reader and it will power up when plugged in.I had a friend bring over his brand new Snap On Diagnostic tool and it will not work either. Apparently there is a power supply problem from the ECM or PCM? Forgive me if I am using the wrong terms. I know both readers are good and work on other Duramax trucks.
The engine turns over but does not attempt to fire. It feels and sounds like there is little or no compression. Very small puffs of white smoke out the exhaust. The oil is full and good and the overflow tank for the coolant is empty. The truck has a EDGE with Attitude type box on it with gauges on the display. I have not checked the fuel system pressure yet since I wanted to see what codes are stored first. I am not sure how to proceed since I cannot get a code reader to work? Any ideas????

check fuses for the cig lighter and power ports. The OBD II port pulls power from them and you cannot link to it if there is no power to the port.

Thanks I did not know which fuses it pulls power from so I went thru them all. In the cab and the under the hood. No blown fuses that I can find. I will go back and look closely at the lighter power port fuses. Thanks for the info. I should also add I completely disconnected the Edge to make sure it was not an issue.

This is just a WAG, but we had a california emmisions truck in the shop a while back that had a bad oil pressure sensor that had the whole truck down. A lot of the sensors pull power from the same 5 volt bus and if there is a short to ground it kills all of them. In the case above the rail pressure sensor was reading max pressure so the computer was keeping the FPR (FCA) from opening when the truck was cranking causing a no start situation. I pulled my hair out for two weeks running down wires and checking schematics before I found the sensor that was causing the problem.

Yes, I'd check compression also if the overflow is empty

phale said:

This is just a WAG, but we had a california emmisions truck in the shop a while back that had a bad oil pressure sensor that had the whole truck down. A lot of the sensors pull power from the same 5 volt bus and if there is a short to ground it kills all of them. In the case above the rail pressure sensor was reading max pressure so the computer was keeping the FPR (FCA) from opening when the truck was cranking causing a no start situation. I pulled my hair out for two weeks running down wires and checking schematics before I found the sensor that was causing the problem.

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Thanks for the warning as soon as get power to the OBD2 and check for codes I will know more.

JD4440 said:

Yes, I'd check compression also if the overflow is empty

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Yea a compression test is definately something I am planning on doing. I just want to see what codes it has first so I have some sore of starting point.

First thing I'd do is remove the edge.
Second thing as I told you on the phone is get the OBDII port working and data log commanded and actual rail pressure while cranking. This will tell you a lot and give you a direction.

IdahoRob said:

First thing I'd do is remove the edge.
Second thing as I told you on the phone is get the OBDII port working and data log commanded and actual rail pressure while cranking. This will tell you a lot and give you a direction.

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The first thing I did was remove the Edge :rockwoot: I am still trying to find power to the OBDII port so I can run codes. Thanks for the info Rob I really appreciate it :bow: I was not sure which fuses power the OBDII so Iwent thru them all and could not find any blown fuses. I am going to keep looking.

Obd2 power supply fuse is cigar fuse in the under hood fuse block. If it is a full size snap on scanner it should have it's own power supply. When you turn the key to the run position do you have a check engine light? This is a quick check to see if ecm is getting ignition voltage.

Yes it has a check engine light. The batteries where dead for some time so it reset but as soon as I put new batteries in and cranked the starter the light came back.

I found the wirering problems and got power to the OBDII and even the Snap On scanner now says cannot establish communication :nail:
I disconnected all aftermarket power devises stereo, amps, Edge and no change so I guess I am going to pull the ECM and send it to Rob to have it checked out.

Take a look at the two bale connectors on the engine. This is where the Edge was plugged in. One or more of the pins may have been push back and is not making a good connection. This could be causing all your problems as the buss is wired through them on your model.

Diesel Tech said:

Take a look at the two bale connectors on the engine. This is where the Edge was plugged in. One or more of the pins may have been push back and is not making a good connection. This could be causing all your problems as the buss is wired through them on your model.

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Thanks for the info!!! I will check it out