How to fix limp mode

have vehicle scanned for the trouble code since it goes into limp mode then cuts out -to many reasons can cause problem

I think I would start by hooking the vehicle to a scan tool that is capable of accessing all of the ECU functions and figure out why it is entering limp mode, instead of throwing expensive parts at it hoping it mystically fixes it.

You MUST have the powertrain control module tested for fault codes, that is the first step.

I don't have a solution but I do have a web site for you that discusses limp mode and how to troubleshoot and potentially solve your issue.

Limp mode fix repair and troubleshooting vw seat skoda audi TDI engine

Good luck.
Semper Fi,
Z

year model and engine code will help

what have you done to repair the fault that shows the codes?
from your statement you are removing the codes and resetting the ECM but the codes come back and the vehicle goes back into limp mode
one of the codes (p 0734 --0?) refers to gear 4--incorrect ratio===causes --wiring---TR sensor /switch ---shift solenoids---transmission mechanical fault
If that fault area is not fixed then the TCM doesn't know what gear to select so it goes to limp mode

run fault codes to find what sensor is going outside parameters for this to happen. Limp mode becomes operational from faults detected in the engine and transmission and is designed to prevent expensive damage to the units.

check the serpentine belt and all vacuum lines and also all fuel lines also there might be a problem with sensors

In the VW world it's called "Limp Mode" and unfortunately it's relatively common. Here's a link to some useful info on limp mode

http://www.myturbodiesel.com/1000q_how_to/multi/limpmodetdi.htm

Also check out www.tdiclub.com - these guys know their TDI"s...

Your car goes in "limp mode"!!!
If you scan the EDC-15P engine control unit with a VAG or KTS -BOSCH diagnosis tool you will find this:
"Fault code: P1557 - Turbo Boost pressure control exceeded"
You must try follows if you are able to do this:
1. Engine stopped and ignition switch off. Check all pneumatic connections and hoses between turbocharger actuator = pressure unit for boost-pressure control, boost-pressure control solenoid valve, vacuum reservoir, EGR control solenoid valve, intake-manifold flap solenoid valve, EGR valve with throttle - part of intake manifold. Also the vacuum connection between tandem pump and brake booster. If you find something wrong replace parts. If not go to step 2.
2. Extract the hose of the turbocharger actuator = pressure unit for boost-pressure control part of turbocharger. Instead of the original hose you must place another 1 meter long hose with the same inside diameter, and then you check to inspire yourself the air from the other one extremity of this hose. The mechanical connecting rod of the turbocharger actuator must have a smooth and whole motion. If you can do that with your mouth, then you must replace the boost-pressure control solenoid valve. If you can not reach this with your mouth, then you go to step 3.
3. This is the most difficult work. The problem is that the soot particles deposits inside the turbocharger plugging the variable nozzle geometry mechanism = adjustable vanes of the turbine. If the turbocharger actuator is not able to adjust the turbine vanes the charge air pressure increase too much and ECU (engine control unit) go in "limp mode" = engine protection software. As a result the "limp mode" engine still running until you turn the engine off (ignition switch off) and back on when the "limp mode" is deactivated, but the fault ("Fault code: P1557 - Turbo Boost pressure control exceeded") still remain in ECU memory !!!
4. You must be able to extract the turbo from the engine and then to disassemble the turbocharger, clean inside adjustable vanes mechanism and refit all.
It is some work to do here, but after that you will be full satisfied! NO MORE "LIMP MODE"!!!