Questions and Answers
OD, No OD. OD, No OD...
Q. Hi Vince, I have an 1986 Honda Accord LX I with transmission trouble. First It's an automatic with overdrive. The trouble is when rpm is reached for the transmission to shift into over drive, it shifts, but then 5 sec later it will shift back into third and will constantly shift back and fourth unless taken out of overdrive or slow down below 50-55 mph. I'm guessing some sort of vacuum problem/speed sensor, I have a Chiltons manual but its pretty vague. Any Ideas?
Thanks,
BartA. I have come across this very same problem more times then I care to count. I actually found the solution to the problem when I was working at a Nissan dealer and bought a new Nissan Van. After 4,000 miles it did the exact same thing. I would hit 68 mph ( yeah I know, the speed limit is 55 on that road ) and the transmission would start shifting in and out of OD. No one in the shop could figure it out. There was no codes so we started reaching. I replaced the fuel pump, injectors, throttle body and ECU with no results.
The Technical factory rep had no ideas so we got the engineers in Japan involved. They gave us a list of tests to perform and everything checked out good. The only way we found the problem was another dealer was having the same problems with a number of their cars and someone hit on the problem and entered it into the Nissan database.
The cause was a bad Throttle Position Sensor. They developed a bad spot and when you cruise at a certain speed and hit that bad spot, it would cause the OD to kick in and out. Now you're asking what this has to do with your Toyota? Well Toyota bought their TPS's from the same company that made them for Nissan and they had the same defect.
