Setting Wastegate Voltage
As part of the installation of the Shuenk OEM+ IS38 turbocharger on my Mk7 GTI setting the wastegate actuator to the proper voltage was needed.
That I needed to set the wastegate became apparent when an EPC light illuminated and the “Turbocharger Boost Control Position Sensor Circuit – Implausible Signal” registered. This is the OBD error code P2563.
Oh right, I’d forgot about doing this when I finished the installation.
I found adjusting the wastegate actuator rod from beneath the car to be the easiest way.
I removed the brace that attaches to the turbine housing, shown with the upper arrow. The bolt is 13mm and the lower end is a 6mm hex socket.
The jam nut holding the rod in place is 10mm (lower arrow) and I found using needle nose pliers held in my right hand coming at the rod from the right to work for me to tighten the rod.
Checking the voltage readings can be done using the Ross-Tech VCDS diagnostic software if you have their VAG HEX cable that connects through the OBDII port.
Selecting the “Adv. Meas. Values” in the Basic Functions section opens up a window that will allow viewing many engine variables. Entering “charge” in the search window greatly reduces the number of variables and brings up relevant variables for this task.
The “Charge air pressure control valve uncond voltage sensor” is the reading I checked when I started adjusting the wastegate actuator rod.
Note: When I started the voltage was way off, around 4.7 volts. When I tried to run the “First Adaptation of charge pressure actuator” VCDS would report an “Abort for Safety Reasons” and not complete the adaptation. When I brought the voltage down to 3.9 volts then the adaptation would complete.
Turning the actuator rod clockwise, looking toward the jam nut, tightens the actuator and lowers the voltage reading.
Once I got the voltage around 3.6 volts I went to the Advanced Functions section of the Engine Controller screen and into the “Basic Settings – 04” and ran the “First Adaptation of charge pressure actuator”
This selection is towards the bottom of a long list of functions that are available below the “Basic Settings” title.
Basic Settings Pulldown Menu OptionsWith the wastegate actuator voltage set around 3.6 volts the ECU was happier and ceased illuminating the EPC light when going into boost.
The video from Deutsche Auto Parts also goes through the process.
As is mentioned in the video, you can adjust the wastegate with the turbo installed from above by loosening the bolt and turning the end near the actuator with a finger or two. That worked well for me when I tried it..