Engine Controls - MIL ON/DTC P0299/P0234 Set
TECHNICALBulletin No.: 09-06-93-004
Date: July 21, 2009
Subject: Intermittent MIL/Check Engine Light On, DTC P0299 or P0234 Set (Adjust Turbocharger Wastegate Actuator)
Models:
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)
Please Refer to GMVIS
Condition
Some customers may comment that the SES light is on. Upon inspection, you may find DTC P0299 (Turbocharger Engine Underboost) or P0234 (Turbocharger Engine Overboost) set.
Cause
This condition may be caused by a mis-adjusted wastegate.
Correction
Note
The wastegate adjustment is sometimes a very fine process. When adjusting the wastegate, only small adjustments should be made. Loosen one nut at a time and only adjust the nut one turn at a time; then 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.
Adjust the turbocharger wastegate. Refer to Turbocharger Wastegate Actuator Adjustment in SI.
Troubleshooting Tips for DTC P0299 - Turbocharger Engine Underboost
To increase boost, adjust the nuts (in) towards the actuator; in essence making the shaft shorter.
Troubleshooting Tips for DTC P0234 - Turbocharger Engine Overboost
To reduce boost, adjust the nuts (out) towards the end of the shaft; in essence making the shaft longer.
Warranty Information
For vehicles repaired under warranty, use the table above.
Disclaimer