Hey about one week ago, my girlfriend's car started to act wierd. She was driving home from work one day and all the sudden as she accelerated the stop wouldnt go faster than 20mph. So she slowed down and tried again and it still wouldnt go past 20mph. So she pulled over, restarted her car, and drove away and everything was fine. Next day, she took it to the shop, and they did a diagnostic test on it, and they found nothing wrong. From then it was fine.

Then this morning, it happened again. The car would not go past 20 mph.

I honestly have no idea what could be wrong with it, whether it is something with the ecu or the transmission, idn. Someone give me some ideas on what you think we should do.

 

if you don't have any warning lights on, i don't think there is going to be any codes to pull up.

is it redlining at 20 mph? because that could mean there is something wrong with the automatic transmission not upshifting.

it is only an 05, check to see if it is still under its powertrain warranty.

one thing you could try is just simply resetting the car by disconnecting the battery to see if that helps.

 

Got your pm, but figured I would just respond here to keep it in the same place. You said it was an Altima, so I am not sure what type of throttle system they have.

Is it redlining as mentioned?
If not, does it seem to run strangely at all ?

If it is redlining at 20, it is probably an issue with the auto tranny not shifting. If it is running poorly once you get to 20 and wont go any faster, then I would think more along the lines of fuel or ignition systems. If it is running perfectly fine up to 20, but just wont go any faster, then it could be either a drive by wire issue (if it has an electronic throttle) or an issue with the throttle position sensor, but I would think the latter would cause it it run poorly as well.

To eliminate the throttle, what happens if she puts it in neutral when it is occurring and gives it some throttle? Does it rev all the way up to redline normally or does it hit a certain rpm and stop? Actually it may not reach redline in neutral, as many cars have a lower rev limit while not under load.. but you get the idea.

 

alright i just talked to my girlfriend again...

She said that it does redline and just wont shift... and she isnt sure about the warranty..

Besides the shifting problem there is nothing else wrong that she can notice.

i just asked her about the putting it in neutral issue but she has not responded so i will keep you updated soon