Q: CEL lights p0501 p0500 p1529 u1400 on 2001 Hyundai Elantra

asked by on May 25, 2017

My car get's the codes, p0501,p1529,p0500,u1400 and has trouble shifting down after acceleration as well as taking off from a full stop, runs on a very low idle (less than 500RPM). Gets terrible gas millage at about 18 MPG

My car has 188000 miles.
My car has an automatic transmission.

Codes P0500, P0501, and P1529 are related to vehicle speed sensor input. The engine control unit relies on sensor input from the wheels and transmission - as well as dozens of other sensors - to determine how fast the vehicle is going. If the check engine light is on with these codes present, the ecu will put the vehicle into sort of a "limp mode" where it will run, but not run correctly. Possible causes could be a wheel speed sensor which also provides input for the anti-lock braking system if equipped (most commonly at the right front wheel), or the vehicle speed sensor which is typically located on or in the transmission. Code P1400 is related to exhaust gas recirculation (egr). Through the egr valve a small amount of burned air and fuel is rerouted from the exhaust and back into the combustion chambers at certain speeds to cool the combustion chambers and reduce the chances for ’knock and ping". Although unrelated to vehicle speed, this code may simply be present due to the way the engine is running due to the speed codes. Have a certified technician inspect the vehicle. If replacement of a wheel or vehicle speed sensor is determined to be the cause and replaced, the egr code may go away. If it returns, then the egr system will have to be inspected to find the exact cause for that code.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Our Honda Civic Ex starts and drives but loses the ability to accelerate which causes us to stop cut the car off then on,drive

This can be caused by a few different problems. First have computer tested for stored codes to see if it points you to the problem like a clogged fuel filter or a bad catalyst in the exhaust. If this has...

Battery and starter problems, car won't start even after replacing battery and starter.

I would check the fuses for the starter relay. You may have a blown fuse for the starter. I would have YourMechanic come and diagnose the starting problem further.

All of a sudden my car is making loud noise when I turn it on, and accelerate

You need to find out if the muffler they put on is equal to the factory muffler or did they put the wrong one on and it is too noisey. It is this or there is an exhaust leak. Have...

Related articles

The Best Used Cars to Buy for Occasional Drivers
Not Not everyone relies on their car on a daily basis. Maybe you aren’t the type that deals with a daily commute, and running from here to there constantly. If that’s the case, you may be looking for a car...
The Best Used Cars to Buy If You Just Got Your License
If If you are a new driver, congratulations on getting your license. Now, you need to think about what type of vehicle to buy. Ideally, you’ll choose a used car that isn’t overly expensive, and is reliable and safe while...
The Best Used Cars to Buy If You're a Construction Worker
If If you're a construction worker, you don’t have to worry about hauling a whole lot of supplies and materials to the site – that’s the boss’s problem. As long as it’s big enough to hold your tools (and most...