codes on H1, what do they mean?

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Jul 24, 2012 | 05:01 PM

hnymlk1

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Junior Member

Joined: Jul 2012

Posts: 3

codes on H1, what do they mean?

Hi, We have a 2001 H1 that has started to give us problems.

When cold it runs great but after it warms up it loses power and bogs down under acceleration. Can't get it over 50MPH. If you shut off the engine it is hard to start but will run.

Don't know if it's connected but the cruise control goes out at about the same time as the engine acts up.

Replaced the PMD a month ago. Fuel filter new. Fluids topped off.

showing three codes

P0251
P0335
P0380

Can anyone shed some light on what these mean? I don't want to take it in for repairs and be completely in the dark.

Any help would be welcome,
Theresa & Rob

Jul 25, 2012 | 12:14 PM

3hummers

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Joined: Sep 2007

Posts: 15,028

From:

Quote:

Originally Posted by hnymlk1

Hi, We have a 2001 H1 that has started to give us problems.

When cold it runs great but after it warms up it loses power and bogs down under acceleration. Can't get it over 50MPH. If you shut off the engine it is hard to start but will run.

Don't know if it's connected but the cruise control goes out at about the same time as the engine acts up.

Replaced the PMD a month ago. Fuel filter new. Fluids topped off.

showing three codes

P0251 - injection pump/fuel selonoid
P0335 - crankshaft position sensor
P0380 - glow plug heater circuit

Can anyone shed some light on what these mean? I don't want to take it in for repairs and be completely in the dark.

Any help would be welcome,
Theresa & Rob

PM hummech for a complete description of what you might be looking at.

Jul 26, 2012 | 11:32 AM

hnymlk1

Thread Starter

Junior Member

Joined: Jul 2012

Posts: 3

I don't have permissions to PM somebody! could you forward to hummech?
Thanks

T & R

Jul 26, 2012 | 11:34 AM

hnymlk1

Thread Starter

Junior Member

Joined: Jul 2012

Posts: 3

Also a P0606 is now showing too.

Jul 27, 2012 | 05:12 PM

3hummers

Super Moderator

Joined: Sep 2007

Posts: 15,028

From:

That is the PCM/ECM code. Generally means you have a failing PCM. I will talk to hummech about responding.

Jul 27, 2012 | 11:58 PM

hummech

Senior Member

Joined: Apr 2008

Posts: 125

From: huntington beach ca.

hnymlk1, the p0251 is injection pump cam system, p0335 is crank shaft sensor, p0380 is glow plug system and p0606 is internal PCM failure. i wasgoing to say thatthe first couple of fault codes indicates a PCM failure. based on all the info. it needs to have the PCM replace. make sure that it gets programmed for your hummer.

hummech