2002 Jetta MKIV temp/fuel non responsive.

Hello.

Been the best car I have ever had. Can’t get the temp sensor or the fuel gage to do anything. Checked fuses, replaced coolant temp sensor, pulled the fuel level/filter and replaced. No luck.

Wiring?

Anyone heard of this? Can’t pass smog in Southern California without having it run a drive cycle.

Runs like a champ, of course-

Any insight greatly appreciated-

What's a drive cycle?
Does everything else in your instrument cluster work properly?
All indicator lights come on when you key ON?
Has the car ever had water leaking into the cabin?
Any recent work done?
Your answers might help someone else more efficiently diagnose your issue! You also might consider that your car wants to move to Texas

I'm guessing you put a new radiator temperature sensor in and need one for the back of the head. Fuel sender/pickup probably needs replaced.
https://www.idparts.com/coolant-temperature-sensor-green-oem-4pin-wseal-clip-a4b55-p-959.html
https://www.idparts.com/advanced_search_result.php?keywords=Fuel+Level+Sender+(A4+ALH)
I'm assuming if you get the coolant sensor working it'll pass as I don't remember any regulations saying you have to know how much fuel you need.

OBD works, should've started there. The Instruments communicate through the DLC, same as the rest of the modules on the CAN bus. You can see if it has any DTCs, and see if it is reading the correct values from the sensors (you can even do an output test to make the gauges sweep). I suspect the problem could be a bad solder joint, possibly on a shared voltage stabilizer, inside the cluster.

Once in a while the resistor sweep in the fuel sender/pickup in the tank needs to be wiped off. That wouldn't explain the coolant temp though. I'd go with OH's advice first.

Cheers,

PH