Powertrain, generic · Fuel and air metering, auxiliary emission controls

P0035 Turbocharger/Supercharger Bypass Valve A Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The turbocharger bypass valve A is the compressor recirculation (diverter) valve: it connects the pressure side of the compressor with the intake side upstream of the turbocharger. It opens when the throttle closes quickly at high boost, so the compressor does not surge and the compressor wheel keeps its speed for the next acceleration. It is not the wastegate, which bypasses exhaust gas around the turbine and has its own codes. The valve is either electric or a vacuum unit controlled by a solenoid. P0035 means the voltage at the control output is too high, typically a short to battery voltage; on some engines an intermittent break in the harness has also set this code.

Likely causes

Control wire shorted to battery voltage
Loose contact or broken wire, e.g. harness vibrating from heat
Solenoid coil faulty
Output driver in the engine control module faulty

Symptoms

  • Check engine light on
  • Fluttering or hissing when lifting off the throttle if the valve stays closed
  • Weak response after gear changes
  • Too little boost if the valve stays open

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–350
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

turbocharger bypass valveturbocharger bypass valve wiringengine control module

Related codes

P0033P0034P0039P2261P00C2

References: law.cornell.edu, gsi.ext.gm.com, saabwisonline.com, static.nhtsa.gov.