Limp mode It don't go over 4000rpms It smells like gas

What do you mean limp mode ? This only happens with automatic transmission's . Step on gas an won't go , bog's down ????? Loses power ?????

your not in limp mode , you have a leaking fuel line, it causing low fuel pressure to the motor

if their is a check engine light have the code read ------no such thing as lock down mode you have limp mode which will let you limp vehicle home or to a shop or off road safely sounds like a transmission problem check fluid --look and smell if it looks burnt brownish and or smells burnt try a flush with a fluid and filter change may gey lucky ---look under vehicle and check the selector cable and connections sometimes disconnect or rot away lastely possible internal problem which would need a transmission specialist to look at

You will have to pull up diagnostic codes to pinpoint exact problem, just too many issues can put car into limp mode, check gas cap seal is first thing which can send signal to your ECU to go into limp mode.
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Use a bottle of yellow HEET dry gas to remove any moisture problem in the fuel.

Clean / replace air filter.
Check ATF at level ground. Top off ATF to MAX level.

Bad battery, or bad ground. If thats not it put a code reader on it while its running in limp mode and see what she says.

My 2 experiences with limp mode was on a 93' Chevy. 1 time was the ecm, but it didn't reset until I replaced the ecm. The other time was the main electrical plug that comes from the ecm. The largest electrical plug on the trans. I unplugged it and there was trans fluid inside the plug on the 16 pins that connect the external wire Barnes to the internal wire harness of the trans. This required a new harness inside of the trans and replacing the external harness near the trans. Not an easy fix and may not be your issue, but this issue would "come and go". Fluid would short out the communication at the pins.

need more info what happened when it wen't into limp mode. were you just driving down the road, uphill downhill? there could be any number of reasons. Limp mode is so that you don't wreak the engine. What year car? did it throw an engine light. if so have it read to find out what is the problem. Other causes low antifreeze, low oil, trans overheating. You can try to unhook the pos battery cable for 10 minutes, if that does't clear the computer then you will need to see the dealer.

Your SUV has an electronic throttle body. Unlike the other type which is driven by cable, this relies on multiple sensors in the gas pedal and multiple sensors in the throttle body. If one or more of the sensors don't agree (i.e: one sensor says you're at 80% it while another says 40% throttle) then it goes in to a default mode or "limp home" mode. It basically makes you take it to be repaired because it is unsafe to be driven.

Sound like a possible leak or you have a bad injector. You will not be able to lokk under the car for any leaks due the fuel will evaporate, you will need to start the car and look at the fuel rail while it's running. If it is not that check your fuel filters. If your lines do not have addaquate fuel pressue due to a leak or a dirty filter, it could cause those symptoms...


Good luck!