RPM Jumps Letting Off Accelerator - Toyota Nation Forum : Toyota Car and Truck Forums

Taddeusz · 08-05-2009, 09:26 AM

I have a 2008 Corolla. Every since I got it between a certain RPM range which equals to between about 40 and 55MPH whenever I let off the accelerator to coast the RPM's drop really fast and then a fraction of a second later jump back up to where they should be.

Yesterday I finally was able to take my car into the dealership to check on the problem. They said it is normal for the drive-by-wire system. That the ECM is self-correcting the RPM's.

This sounds fishy to me. I'm a computer guy and ex-electronics technician. I know that things like that need calibration and then re-calibration from time to time. If the car's computer is having to correct the RPM's after the pedal has been released that tells me as a technician that it's getting an input that it shouldn't and that the pedal needs to be re-calibrated.

One of the results of this is that from time to time when I'm coming up to a stop quickly and the RPM's are dropping fast anyway it feels like the car is trying to stall and then quickly corrects itself before that happens.

Is any of this really normal for a drive-by-wire system or does something need re-calibration or cleaning?

Taddeusz · 08-08-2009, 09:30 AM

Nobody has any idea whether or not this is normal for drive-by-wire systems?

mikered30 · 08-08-2009, 10:27 AM

Pull the EFI fuse in the fuse box under the hood for 1 min. Drive around and see if it happens again. If that does not work try the following:

turn key to on position(do not start)
press the gas pedal to the floor for 5 seconds
turn key to off
release gas pedal

wireman134 · 08-12-2009, 09:04 PM

yes it is normal it is due to new epa laws or rules, in a manual anyway, holds rpm during shifts, even bumps em up at about 250 rpms or so,,, had about 5 manuals in the past, this car was very diffucult to learn how to drive with drive by wire, took about 40k miles to learn how sensitive the gas pedal is also

Taddeusz · 08-12-2009, 10:14 PM

I tried both those things and it still does it. I suppose maybe the dealer was right but it still seems weird to me.

BTW, my car is an automatic. I forgot to mention that originally.