The speedometer may stop functioning with code P0722 stored in the powertrain control module (PCM). This may be caused by a worn speedometer gear due to coolant contamination of the transmission fluid. If contamination is found the radiator is most likely at fault. The transmission should also be thoroughly inspected and repaired or replaced as required.Google+
Car Problem Reports
Chevrolet Aveo Speedometer Not Working and/or Code P0722 Stored in PCM
Chevrolet Aveo Problem
Drive Trains Affected: Automatic Transmission, Manual Transmission
Average Mileage: 76,200 mi (32,000 mi - 145,000 mi)
Visitor, 2007 Chevrolet Aveo, Manual Transmission, 32,000 mi
Car bogged down like it mas similar to a misfiring, then I noticed the speedometer was at 0. After downshifting at a coming stopsign, it bogged again & the speedometer picked up again, only to fizzle out again as I accelerated.
having the mechanic repair the speedometer as we speak... mechanic is concerned there's more to it...
Visitor, 2006 Chevrolet Aveo, Manual Transmission
we have a problem with our aveo in our dealership the speedo donot work can anyone help urgent
Visitor, 2010 Chevrolet Aveo, Automatic Transmission, 80,000 mi
I had trans fluid leaking into my radiator, which in turn contaminated my radiator and all hoses, got them all replaced out of pocket only having the power train warranty, haven't even had the car 3 years.
After getting the radiator and lines replaced, then had to replace thermostat.
One week later my speedometer stops working, gear is morphed and not sending correct signal to output speed sensor.
Dealer claims problem was caused by radiator leaking coolant into transmission fluid.
None of which is covered by warranty.
This car sucks.
Visitor, 2011 Chevrolet Aveo, Automatic Transmission, 53,000 mi
I have an automatic, but yes, radiator went bad, and I have to replace my transmission due to coolant mixing with the trans fluid. good thing I bought the top of the line warranty, or it would have been all my expense.