(Long Shot) Extrememly Random "Power Reduction Mode" with a 2007 Hummer H2
03-29-2011, 11:22 AM
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(Long Shot) Extrememly Random "Power Reduction Mode" with a 2007 Hummer H2 Here is the stats on the truck
2007 Hummer H2, stock other then a Magnuson Supercharger.
Installed the blower, loaded Magnuson tune that came with supercharger kit. As well very well truck drove great other then two issues.
- Horrid gas milage around the city.
- Randomly would go into power reduction mode (pull over, turn key off for 30sec, fixed)
Owner took it to a local shop to fix the issue, and tune it. (Still same results)
Then owner came to me to fix it, and I said that it shouldn't be an issue.
However.....
It has no codes in the ECU or the TCU, other then a Class 2 Data whatever error. I was really expecting to see something like a MAP, or MAF, or ETC code of some sort to put the truck into a power reduction mode so many times.
Anyways, I tuned the ECU to pick up the milage (which worked big time) yet I couldn't find ANYTHING out of line in the Magnuson tune (or the other shops tune) as far as something that would cause the power reduction mode. (Not that I expected to, their base tunes are always nearly spot on if the cars/trucks are in fact stock, with no issues) So I figured it was a fluke and let it go.
Guy calls again, says its still doing it. Talk to GM about it, they said it was a throttle pedal problem, and they could fix it. Well it gets the new pedal and a few weeks go by, and out of no where power reduction mode again.
Finally I told them to have GM flash the truck to the latest stock OEM GM program, and I would build a complete base tune from that. Well, I did that..... and you guessed it... .same result.
Whats fustrating is the following..
1) This thing can go weeks on end without going into that mode. Then sometimes it will do it 3 times in like 15min. There doesn't seem to be any rhyme or reason to it, and its gonna make me pull my hair out.
2) NOOOOO CODES to even help figure it out, other then that Class 2 Data Bus.
3) It will do it without the engine running. IE: leave the key in the on position run inside a gas station to grab a coke, come out... and sometimes its in PRM, even with the engine off?
The truck has an Aftermarket Radio in it, so I figured that was the issue with the Databus? So not really to worried about that one.
Has anyone had this issue....?
Is he going to have to pull the blower off, and see if it does it stock?
Thanks in advance. I am losing what little hair I have left on this one.
EA
2007 Hummer H2, stock other then a Magnuson Supercharger.
Installed the blower, loaded Magnuson tune that came with supercharger kit. As well very well truck drove great other then two issues.
- Horrid gas milage around the city.
- Randomly would go into power reduction mode (pull over, turn key off for 30sec, fixed)
Owner took it to a local shop to fix the issue, and tune it. (Still same results)
Then owner came to me to fix it, and I said that it shouldn't be an issue.
However.....
It has no codes in the ECU or the TCU, other then a Class 2 Data whatever error. I was really expecting to see something like a MAP, or MAF, or ETC code of some sort to put the truck into a power reduction mode so many times.
Anyways, I tuned the ECU to pick up the milage (which worked big time) yet I couldn't find ANYTHING out of line in the Magnuson tune (or the other shops tune) as far as something that would cause the power reduction mode. (Not that I expected to, their base tunes are always nearly spot on if the cars/trucks are in fact stock, with no issues) So I figured it was a fluke and let it go.
Guy calls again, says its still doing it. Talk to GM about it, they said it was a throttle pedal problem, and they could fix it. Well it gets the new pedal and a few weeks go by, and out of no where power reduction mode again.
Finally I told them to have GM flash the truck to the latest stock OEM GM program, and I would build a complete base tune from that. Well, I did that..... and you guessed it... .same result.
Whats fustrating is the following..
1) This thing can go weeks on end without going into that mode. Then sometimes it will do it 3 times in like 15min. There doesn't seem to be any rhyme or reason to it, and its gonna make me pull my hair out.
2) NOOOOO CODES to even help figure it out, other then that Class 2 Data Bus.
3) It will do it without the engine running. IE: leave the key in the on position run inside a gas station to grab a coke, come out... and sometimes its in PRM, even with the engine off?
The truck has an Aftermarket Radio in it, so I figured that was the issue with the Databus? So not really to worried about that one.
Has anyone had this issue....?
Is he going to have to pull the blower off, and see if it does it stock?
Thanks in advance. I am losing what little hair I have left on this one.
EA
03-30-2011, 02:06 PM
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So after doing some digging, another buddy I believe has found the solution.
After basically agreeing that it HAD to be something with the throttle body, he pulled back the harness that was covering the wires going to the throttle body.... and guess what, there is a RANDOM butt connector on the power wire, leading to the throttle body.
Wiggle the harness, and guess what.... you can hear the throttle blade moving.
So, basically I am "thinking" that this has been the issue all along. I however am not going to say that its 100% fixed, until some time goes by. (cause this issue is so random)
So that begins the question. How did the butt connector get there, and why? The truck has never been anywhere other then the purchasing dealership, and the blower kit doesn't have you extend any Throttle or MAF wires. Hmmmmmmm
EA
After basically agreeing that it HAD to be something with the throttle body, he pulled back the harness that was covering the wires going to the throttle body.... and guess what, there is a RANDOM butt connector on the power wire, leading to the throttle body.
Wiggle the harness, and guess what.... you can hear the throttle blade moving.
So, basically I am "thinking" that this has been the issue all along. I however am not going to say that its 100% fixed, until some time goes by. (cause this issue is so random)
So that begins the question. How did the butt connector get there, and why? The truck has never been anywhere other then the purchasing dealership, and the blower kit doesn't have you extend any Throttle or MAF wires. Hmmmmmmm
EA
03-30-2011, 02:43 PM
#3
Sounds like maybe the pigtail to the throttle-actuator was replaced.. That would explain the butt connectors.. Also, those throttle-bodies are a big problem child.. To give you an idea; we've sold 14 in Feb, 15 in Jan & are at 9 this month at our dealer. This same throttle body fits all 03'- 07' 4.8, 5.3, 6.0 in the trucks, suvs & h2's.
