05 duramax problem

[scotts62]

There is a guy that I work with that has a problem with his 05 duramax 6.6 automatic with about 80k. I haven't had a chance to check it out yet until be brings it to the shop next week, he lives a bit out of town.

He was coming to work driving about 40mph and said it just acted like there wasn't any power there all of a sudden and the rpm won't go past about 2200 and is real erratic as it does rev. Said it starts up and idles fine and can drive it up to about 30-35 mph before it starts cutting out and running bad. He got it home and changed fuel filter just to see but it didn't help. After it sat for a bit he started and said it reved up like normal then a few minutes later went right back to running bad. Just wanted to get the ball rolling of things to check or if anyone has run into this before by chance?
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[rwolf9653]

It sounds like it is going into safe mode or limp mode. Did he mention it throwing a light? I am not familiar with the newer models, but the older ones would give you just enough power to get home, and restrict higher RPM's until the problem was fixed.

[scotts62]

Yes he said since then the engine light has been on.

Originally Posted by rwolf9653

It sounds like it is going into safe mode or limp mode. Did he mention it throwing a light? I am not familiar with the newer models, but the older ones would give you just enough power to get home, and restrict higher RPM's until the problem was fixed.

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[northerngmc]

Sounds to me like the truck went into limp mode.

Two common problems with the 04.5 and 05 Duramax is wiring problems.

First thing to check is were the wires go over the alternator bracket. Cut the wire tie off and check if the wires are chaffing on the bracket. Mine were! Once they bare and ground to the bracket you have problems.

Second to check is the injector wiring going to injectors 2 and 7. The wires are a little too short and cause problems. GM has a longer harness available. Do to www.dieselplace.com and search "ice pick". Some guys drive an ice pick into the wire connector for the injectors and this tightens the connections back up.

Anyways I had both these problems on my 04.5 LLY Duramax.

Good place to start.

[northerngmc]

Here is the link to the ice pick fix......

http://www.dieselplace.com/forum/sho...d.php?t=142114

[scotts62]

Ok I'll check it out thanks guys.
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[northerngmc]

While you are under the hood take 5 minutes and tighten the clamps on the air intake hoses to the turbo to the intercooler and back to the intake.

My 04 threw a code early this summer and it was for low boost pressure and a little research told me to check the clamps. I was amazed and how loose they were. I tightened them up and no more code. This only set off a code and not limp mode.