Transmission and tire pressure


#1

I was told that low tire pressure could cause the transmission to not work correctly. I have a 2002 C230 Kompresser sport, automatic, and on occation the transmission would get stuck in low, I could get the transmission to shift if I put the car in netural and then back to drive. This became more frequent and would not correct by moving the shifter to netural, it would correct if I pulled over and turned off the car and on it would shift again. I thought a sensor could be causing this. There was no bad sensor found nor was there a low fluid problem. The guys who did the work told me that low tire pressure could have been the cause of the transmission problem. Tire pressure was set to recommended psi and I monitored it with care and have not had a problem with the transmission since. I can’t understand the relationship between tire pressure and transmission function, even though the problem seems to be gone.


#2

I’d say the cars’ computer is set too sensitive to allow the tranny to overcome this problem. Unless the tire pressure was to the extreme. Just a guess tho.


#3

People have been driving for decades with underinflated tires and never had any sort of transmission problems such as you described. Furthermore, your temporary cures suggest there was no relation to the transmission problem and the tire pressure. I’m inclined to dismiss the mechanic’s explanation as utter hogwash. Another possibility, quite possible, is that you misinterpreted his casual statements about transmission pressure as being tire pressure. It happens all the time.


#4

Remember; to really screw things up, a computer is required. Without computer controls, low tire pressure would only make it harder for the transmission and engine to work. With computer controls, all sorts of new things can happen.


#5

Normally I would not expect the transmission to know or care that the tyres were low, if they were equally low. Some power train parts could be damaged in some cars if they were unequally low.

Other than that low pressure will make your car less safe, less reliable, lower the mileage, and give what I would consider a poor ride.

I don’t see how tyre pressure is causing your problem.


#6

thanks for the info, your explaination seems more logical to me.


#7

that’s what i think too. just needed some feedback because the problem did in fact go away with correct pressure. thanks for the help


#8

01010101011101 i tend to aggree, but as the computer resets when rebooted i don’t know how to tell until massive failure occurs


#9

thanks for the help. the information makes me feel better


#10

Bunk. While extremely low tire pressure could cause increased drag sufficient to affect transmisison shifting, it would have to be almost completely flat. You clearly have a tranny problem…or had a problem and they corrected it. It is possible that in the process of working on the car they reprogrammed the tranny control module without ever really finding out what was wrong, corrected the problem, and attributed it to low tire pressure.