Having some issues with my 2009 HHR SS with Stage 1.

The vehicle starts to hesitate at lower RPM's (2000k) after about 10-15 minutes of driving. After the code is thrown, the boost is gone and the car still continues to hesitate. It's almost like the fuel is cut off for a second or two.

The engine light has come on with the P0556 code but not with the P0101 code. Of course the light was NOT on when I brought it to the dealer and they say they can't do anything unless the CEL is on (not sure I believe that).

Regardless, here are the code descriptions:

P0556 Brake Booster Pressure Sensor Performance
P0101 Mass Air Flow (MAF) Sensor Performance

Is this the dreaded "loose connection" issue?

Any help would be appreciated.

 

Could be loose connection. Saying they can't do anything without the CEL is bull. If they can read the code, they should be able to troubleshoot it.

 

Man there have been a lot of these lately (myself included).

I had it happen twice (I don't know which code/s were thrown but the symptoms are similar). The first time it fixed itself before I brought it in and they couldn't replicate it. Happened again a couple weeks later with no boost and wouldn't accelerate past about 75-80mph. Took it back in and they said there was water in the wiring from the A/C condenser and re-routed the wires. AFAIK they didn't do any soldering or wrap the wires any differently but as of now the problem is fixed.

Agreed with the guy above me though, there's no reason they can't fix it. Keep on 'em.

(Also side note, driving this car without a turbo was minor torture.)

 

JB, check to make sure all the boost connections are tight. I had the P0101 code pop up when the Hahn hotside piping came loose at the IC. I switched back to the stock piping for now, cleared the code and tightened all the clamps down-no problems since and I max out at 23-24psi. Also check to see if your SS needs the brake booster upgrade? I know you have the auto and that upgrade is mainly for the manuals, but it won't hurt to look into it. Check w/ ChevyMgr but if it was built before 1/09 or 2/09 you might need it.

Later
Allex

 

Checked the connections, tightened a few screws and the car seems to be running better.

Only one incident with hesitation over the last few days. Problem not solved but manageable for the time being.

 

Good to read that you're at least headed in the right direction then!

Later
Allex

 

OK, now I threw a P0236 code "Turbocharger Boost System Performance". It looks like this is the TMAP sensor / AC Issue.

She's going back in next week.

 

UPDATE - Dealer figured out that the issue is with the boost sensor. Also needs to replace the intake pipe which contains the blow-off valve.

The only problem is that the parts are "US Only", which means they will take around five days or so to get shipped up here.

 

Maybe check in the F/S section to see if anyone has the pipe you need For sale??

 

Update - Part is STILL not available. The lower boost sensor is what they are looking for, I believe.

Word from my dealer is that they have to get the manufacturer to make an additional batch, or somehow find a spare somewhere. ????? The part is not available at any dealer in Canada OR the US.