2004 Volkswagen Jetta Lots of Issues

Hi there,

Thank you for the donation,

This is a throttle position sensor fault code, so i would be looking at replacing that sensor, earth out the coolant temp sender wire and if the gauge goes full deflection replace the sender if not check the wiring and the gauge as for the fuel gauge you will have to get the tank sender checked as well, start here.

mark 9mhpautos)

I was hoping to get more detailed information then that.. I can google P0221 and it will tell me what it is. I also mention that I already changed the Thermostat and the ECT. The Previous ECT was fryed up. So that def was causing an issue. Installing a new one however still did not allow the gauge to read properly. The Engine TEMP gauge DOES NOT Work at all. Nor does the FUEL Gauge. I dont understand how earthing out the Coolant temp wires will do anything?? Can you Elaborate on that? And what do u mean if the gague goes full deflection? Could you please provide me with more detail information?

Regards,

Orlando

The TPI reads throttle percentage against engine load requirements, this reading is sent to the ECU and it is only part of the information required to set injection timing, spray duration, ignition settings, id the TPI is out of calibration or sending conflicting information if relationship to other readings at the input of the ECU, it will determine that this is a fault and the code will be set, the temp sender will be an earth resistance sender, that is the sender when heated by the coolant will alter resistance and send a varying signal to the gauge, the hotter it gets the less resistance there is so the gauge deflects further(goes from cold to hot) earthing the wire with the ignition on gives a zero resistance so the gauge will deflect to hot straight away, the tank sender works in a similar way but not on heat, it uses a float and a wiper arm mover a winding, the more it moves the more the gauge moves.

Mark (mhpautos)