Well, I'm at 6595 miles now and I've had the same CEL occur 3 times now. I can drive it around on trips less than 100 miles with no issues, but if I drive more than 100 miles straight, my HHR gradually starts boosting less and less until it won't boost at all and the CEL 2178 comes on (rich condition). The third time CEL 101 was also stored (MAS). 3 seperate dealers are clueless. Seems to me it has to be an issue with the electronic wastegate or ECU since the turbo stops boosting, and once you let it cool off for a while, the CEL remains but the car drives fine again. However, GM keeps giving the techincians lame things to check for (leaks, lose hoses, etc.) and won't let them actually try and diagnose the issue. The last tech actually tried to convince the GM tech line that the problem has to stem from the wastegate and/or ecu but was denied his request

Personally, I think the electronic wastegate actuator or ecu is overheating and going nuts, but what do I know.....I've only built turbo race cars since the early 90's (which is before many of the tech's I've dealt with were born I think....LOL (no offense to the younger members).

Anyway, I guess I have to sit and wait right now till you guys rack up some miles to see if it pops up for others. It started around 5000 miles the first time. From what we can tell, I have one of if not the first HHR SS delivered to GA (delivered Jan 15'ish) so it may just be a one-off gremlin.

 

I think you have a connector problem at the pcm or possibly the MAF circuit.

 

Personally, I think the electronic wastegate actuator or ecu is overheating and going nuts, but what do I know.....I've only built turbo race cars since the early 90's (which is before many of the tech's I've dealt with were born I think....LOL (no offense to the younger members).

The ecm pulses the wg solenoid to control boost and I am with you that
it is probably ecm trouble BUT this ecm also controls the throttle and if it sees
a problem (rich, MAF sensor) it could command a closure of the throttle
which would then give you the low to no boost u are seeing.
Dealers have a data logger ( other than the Tech II ) which they can put on
to capture data when a problem happens. Ask that it be put on so that the
techs can see something other than history codes.

Also, the fact that the codes do not agree when they happen again,
suggests a connector problem like a previous user commented.

turbofreak
retired engineer GM road racing cars

 

Wow, I have not heard of any problems like this before. I have 5,100 mi. on mine now so we'll see if anything develops on mine. Hope not!

Good luck solving your problem Jonboyb. Thanks for that fantastic input Turbofreak, you are a geat resource for info for us SS owners!

 

turbofreak is right, call your dealer and see if he will let you drive with the VDR (vehicle data recorder). You can then take the snapshots of what went down when the SES light was triggered. I have had customers do this before that had problems that only occur after extensive driving.