Y77/1 BOOST PRESSURE TRANSDUCER
2nd code was P035596, changed coil #5 and cleared code & hasn't come back on.
3rd code P023409- Boost pressure turbo 1 too high. started with blowing out the vacuum line from the pressure transducer Y77/1 to the vacuum pump, vacuum line was filled with oil.
changed the vacuum pump, pressure solenoid and blow out the vacuum lines.
cleared codes
duty cycle before and after
before part replacement.
5% actual 65-97 target
after
74% actual 65-97 target
went for a few long drives over the weekend, boost pressure seems to be happy again
Xentry scan revealed error code "P023409 - The boost pressure of turbocharger 1 is too high. There is a component fault."
Repair steps/logic:
Usual suspects (in this case): pressure sensors - checked, OK; vacuum hoses - checked, clean and no leaks, OK; blow-off valves - checked, OK; wastegate actuator stuck - possible, but not probable since the car has less than 10 thousand miles and ECU actually opens them when entering limp mode, so before disassembling turbos we decided to check remaining to components in the system: vacuum pump - no oil found in hose to pressure transducer, assumed that pump is OK; boost pressure transducer (Y77/1) - ordered a new part from MB, changed, problem went away.






