Hi,
I have a 1990 Honda Accord Ex with automatic transmission and 120K mileages on it. The overdrive light will come up randomly and transmission shift will not change to gear 4 (up to gear 3 only.). I have tried to fix the problem a few times. Below is the description the all of the repairs I have done in two repair shops:
About 3 months ago on repair shop #1: The overdrive light would always be on and transmission gear would not change to gear 4. I believe the shop did some repair on the overdrive control itself, the problem went away.
Three weeks after the first repair: The issue came up again. I brought the car to the second shop. This time the shop diagnosed the issue as transmission issue. The shop replaced the transmission with a used one.
5 weeks after the transmission change: the speed speedometer stopped working and the override light issue came back. I heard mechanical cracking noise from the car. I brought the car back to the shop. I thought the speed cable was broken (I am not sure if I am using the right terminology.), but the shop told me a mechanic part that connected to the cable was broken. The shop replaced the part.
4 weeks after the repair, the overdrive issue came back again. The light would constantly be on. I brought the car back to the shop and the shop owner saw the overdrive light was on. On the second day, when the shop owner started the car, the overdrive light was off. He drove the car around, but the issue just wouldn't come cup. He bought a replacement part for the speed sensor, but he told me that he didn't think the speed sensor's caused the issue (he used an electronic test equipment to test if there was any issue, but the equipment did not indicate any thing wrong with the car.). I told him to replace the speed sensor anyway.
Two days after the previous fix, the issue came back. This time the shop owner told me the test equipment indicated some problems with the car's control computer (he told me the equipment returned code 19, 24 (I may remember the numbers wrong)). He refreshed the computer's setup and drove the car home to make sure it worked this time. I went to his shop to pick up the car last night. The issue came back after about 4 miles of driving. The overdrive light would come up and disappear randomly. It went away after about 10 miles of driving. This morning the light came up after about 5 miles of driving. It stayed on for the rest of driving (13 miles of driving totally.).
Since I have replaced just about everything, I am deciding on what I should do next. I do believe the second shop was trying to fix the issue, but I am just getting a little tried of all the time and money spent on this issue. Based on what people have posted on the net, it appears to me that this issue might have something to do with the transmission control computer. Should I bring the car to a Honda dealer? I live in San Jose, California. If anyone can recommend a good repair shop or dealer, I will appreciate it.