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1999 Accord EX Coupe Transmission problem

01-22-2007, 01:20 PM
hi guys
I have a 1999 Accord Coupe EX. it has almost 200K miles. During the summer of 2005, my transmission had problems so I had it rebuilt. Now, a little over a year later, the transmission is acting up again. I have to let it warm up or it won't shift. also, sometimes when I let it warm up, the car is in park and the car is revving the engine on its own. The rpms are going up and down. When I take it out of park, it's ok. After it warms up, it will shift but it sticks a lot. Today, the rpms were going almost all the way up and it was jerking (almost bucking) really hard before changing gears. this is really annoying and I don't know much about cars. Does anyone think I need get the tranny rebuilt again?


01-22-2007, 01:33 PM
I don't know if it's common to Hondas, but that's precisely how GM cars act when the TPS (throttle position sensor) is going bad...hunting for idle speed, revving on it's own, holding too long, overrevving and shifting abruptly...

The control module uses the info about throttle angle from the TPS to decide the right rpm to upshift, based on vehicle speed compared to throttle opening, so for example if it would shift to second at 22 mph under normal conditions, with the throttle at 30%, when it sees the throttle at 80% because you are standing on it, either racing or pulling a load, it will hold first gear to a higher speed and rpm before shifting...and so on until the throttle is released...

When the TPS signal gets corrupted, the tranny module can't guage throttle opening, and shifting is erratic, idle is affected because the engine module can't tell when the throttle is closed, so it idles too high, etc...

Try unplugging the TPS and see what happens. If the shift patterns change dramatically, that is probably the problem. It may shift at the same speed regardless of throttle application with it unplugged. That is to be expected. You just want to see if the excessively long hold and upshift abruptness go away....

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