Hey folks, My fiancée and I bought a 2002 Prius w/ 100k miles on it about a year and a half ago. Since then we've put about 30k on it, and starting last April or so, the MPG has been gradually dropping. At first it wasn't so obvious, but now we're averaging around 21/35 -- which is paltry to say the least. We've replaced the voltage inverter and both the electric-motor battery and the starter battery - plus maintaing air in tires. Our mechanic here in SF also had the car at their shop, and after weeks of testing and driving it, they couldn't figure it out either. No computer codes, no nothing. Obviously this is turning into a bit of a money-pit. I have wondered if maybe the ECU needs to be replaced? Has anyone had any experience with this issue? I saw on the forum that their were similar issues with a GII Prius. Any thoughts would be appreciated. Thanks.
It's not that, we just got the battery replaced about 6 months ago. Could the ECU be involved in any way?
Ok- I reread you post- you called it "the electric motor battery". You replaced it with a new hybrid battery or one from a used vehicle? Have you brought it to a hybrid specialist like a Toyota dealership?
Yes, the hybrid battery I meant to say. We have taken it in. Luscious Garage here in SF, who specialize in hybrids (they service all the taxi fleets' hybrids and are very reputable). They had the car for almost two months and couldn't find anything. No computer codes, nothing on our dashboard; no indication whatsoever.
Is it an option to take it to Toyota? No disrespect of Luscious, but Toyota is the mother ship. Not an exact comparison, but in about '94, my Jetta had crazy problems - it might run fine, or fail. I took it to VW / german car specialist in Santa Clara who had it for days and had no idea what was wrong.... Finally I took the Jetta to the VW dealer who correctly diagnosed a bad ECU. Replaced it and it was fine thereafter. I would take the car to Toyota and their Prius specialists should look at it.
You may be right about that. I guess I only expect the dealer to gouge, but at this point I'm happy to try anything.
You never answered Jacob- did you replace the hybrid battery with a new one from Toyota or a used one (from salvage,etc) ?
I would check the wheel bearings and brakes. Look for something that is causing drag. Bad wheel bearings cause excessive drag as do warped rotors.
mine did the same thing right before winter. here my front right caliper was stuck , the car would not pull to the right when braking or shake or anything. but my milage dropped to about 37 because of it. so i jacked up the car and checked all brakes, once i got to the front right tire it was hard to turn, i pryed back on the caliper, and spun the wheel, all good, reapplied and tried to spin it, it was tight again. bought a new caliper and installed it, my mileage went right back up to 46+. try that
