[Nemo01]

Okay, I have had an ongoing issue with my 08 Smart. When driving down the road at 65-70 the ESP light comes on and it goes into limp mode. I have to pull over and turn the car off and on a couple of times for it to reset. I replaced the battery because it needed replacing and noticed that the problem went away for a while. It is back again, but doesn't happen all of the time. Yes, I checked the reluctor rings and they look great. I had to replace one of the axles in the rear due to a badly torn boot, but the problem still didn't go away. There is the background on the issue...

TODAY I got in the car to run some errands and when I went to take off, the ESP light came on and the check engine light came on. My scan gauge read P2138, which I know is a throttle position sensor. When I reset everything, the light would still come on. I reset it about 5 times, and then it finally went away. I have had codes pop up in the past and it is either P2138 or P2121. Do you think this could have been my problem all along? An intermittent TPS? How hard is it to replace? Where can I get one? The local parts store? Just hoping to hear some insight from others! The car has 84,000 miles on it. I love the car, but this problem has become really annoying.

 

[Rustedwrench]

In order for the ESP system to operate correctly the control systems must be able to know the position of and operate the throttle. If a throttle position sensor signal is dropping out then you get limp mode. I think you will find the throttle position sensor only comes with the throttle body. Plenty of used ones available if you wish to throw a part at it.