This vehicle was towed to our workshop. The customer complained that the clutch might be at fault because the engine has no power. The vehicle can’t go faster than 60kmph. The thirst thing I have done is to plug in the scanner and I got the following fault: P0046 Turbocharger/Supercharger Boost Control ‘A’ Circuit Range/Performance Current. Now this point to the turbo, either the turbo is not operating or something is wrong with the electronic control of the turbo. I have inspected the turbo turbine wheel and spun the shaft to see if it runs freely. There is no oil in the turbo and when the engine is idling there is no smoke, all positive signs. I have tried through the scanner to do bidirectional action to enable or to move vanes, the electronic motor should move a shaft up or down to changes the position of the vanes.
This did not happen. I have unplugged the wiring plug from the turbo electronic control. These wires are there to control the motor and the position sensors. I have connected 12v directly to the motor and it moves up or down, but I notice it does not go down completely, there is an adjustable stopper where the shaft should rest on when it goes down completely. I have replaced the turbo driver control module see the image below.
After I have replaced the turbo driver module the motor still did not move with bidirectional action. I have connected 12v directly to the motor and this time when I touch the motor connections the connections made big sparks. the motor doesn’t want to run or move the shaft. There is either a short in the motor or the vanes are stuck. The next option was to replace the turbo with all its electronics. After I have replaced the turbo I could through the scanner move the shaft up or down. The shaft also stops on the adjustable stopper. Another important thing to observe is when you switch the ignition on (not cranking the engine) you will hear the motor of the turbo for a few seconds moving the vane shaft a little bit up and down. I think the control module is testing the shaft to see if it moves freely or is stuck. You will also hear the motor is buzzing. This happens because the motor is powered by modulation frequency. This did not happen with the old turbo and turbo driver module.
If you hear and see these actions then your turbo is ok. If your vanes are stuck the motor can’t move the shaft and it might damage the turbo driver module.