P0299 or P0234

Fix a turbo trouble code on GM

GM has issued a service bulletin #09-06-93-004 to address a check engine service engine soon light and trouble codes P0299 or P0234 on the vehicles listed below. The P0299 Turbocharger Engine Underboost or P0234 Turbocharger Engine Overboost codes pertain to the turbocharger wastegate.

2008-2009 Chevrolet Cobalt, HHR
2008-2009 Pontiac Solstice GXP
2008-2009 Saturn SKY Redline
2008-2009 Opel GT
2008 Daewoo G2X with Engine RPO LNF and LDK (Europe)

GM says the condition may be caused by a mis-adjusted wastegate.

Turbo Wastegate

If you’re wondering why your airbag light is on, read this. GM has issued a service bulletin #09-09-41-004 to address an air bag light on issue with the vehicles shown below. When scanning for trouble codes you may find B0012-02, B0012-0E, B0013-02 or B0013-0E stored in the computer.

You can adjust the wastegate yourself, but it is a very fine adjustment process. When adjusting the wastegate, make only small adjustments. Start by loosening one nut at a time. And only adjust the nut one turn at a time. Next, tighten the other nut against the shaft and test drive to verify. This may have to be performed several times to achieve the desired boost level. To ensure proper adjustment, the vehicle should be at full operating temperature when testing. The vehicle will be very hot and may need to cool between adjustments. Too large of an adjustment can cause repeat DTCs.

©, 2015 Rick Muscoplat