I've had a problem...the boost gauge now sweeps erratically from zero to negative pressure...jumping all over the place, sometimes just stuck on zero. Its not the car, the actual performance of the car is perfect. No engince codes are generated.

So, the dealer replaced the gauge....I didn't even drive the car off the lot, the new gauge did the same thing as the old one. Right back into the garage....

Now we are ordering a new gauge...half a week's wait...

I'm wondering if this the Engine control module's output to the gauge, instead of the gauge itself...

Are others experiencing erratic gauge movement?

 

What I would more likely suspect would be a problem in the wiring up to the boost gauge or at the connection itself. I do not know exactly how this gauge works, but most gauges use a few magnets (They can be permanent magnets, but are usually electromagnets) to control the gauge's position. If the wiring is shorted or has high resistance this kind of thing could occur.

I mean, if changing the gauge once doesn't fix the problem I highly doubt another gauge will, but it's possible I guess.

 

Hmmm...problem seems to not show itself if the engine is cold, starts up if the engine is hot. Might be the ECM output to the gauge....something may be shorting as the temp rises. Doesn't throw a code though, so it is something happening after the "processing" of engine inputs....

 

I'm not sure man, the dealer should figure this out for you as long as your still under warnity. Wish I could help you out.

 

I had this same problem with mine. It was a faulty gauge, and they had to order it from autometer, that's why it takes so long.

 

Ok, figured this one out...

It was not a problem in the engine compartment...it was the gauge...

If the cabin temperature is hot...IE, vehicle out in the sun....the gauge sweeps erraticly, or stays at zero. If the cabin temp is cool....from being in the garage for example...gauge works perfectly.

If anyone else has this issue, it apparently does require a new gauge.

 

I have noticed that temperature can affect the gauge which is why mine is permenantly stuck on -40kpa unless i give it smack on the side but then only works for a couple of seconds then its bakc to where it was before.
the reason why i have not took it in to get it warrantied is cuz i have had bad experience with gm service before and don't want this car messed up like they did with my last.

 

mine goes from way low to like 15psi because i stick my boot in it hard!!! anyone else have this happen!? woot!