day_your

I have a '91 accord LX and a few weeks back the D4 indicator on the dashboard just started flashing but the gear seemed to be transmitting normally, then after some weeks, it started a new problem: in the mornings when I start the car, the D4 indicator comes on and remains on even if the car is on park (the P indicator is also on), if I switch the gear to reverse, the R light comes on and the D4 light remains on also. The D4 light stays on for a while and during this period, the gear doesn't switch to it's next (it remains on it's initial gear even when it's time to change).. after sometime, the D4 light goes off (I can only know if I put the stick to any other gear besides D4, that way, only the gear I've engaged indicates on the dashboard) and the gears start to work normally and change fine.
The problem got worse and this time, it disengaged from the passing gear (as if switched to neutral) and it took alot of effort before it could engage itself in the next gear... So I took it to a mechanic, got the gear serviced (changed the oil), a sensor was bad so I changed that too. The mechanic also said there was a problem with the AT control unit but could be fixed.... When the mechanic was done with it, everything seemed to working well (mechanically) but the situation was only reverted to it's first problem stage (D4 light blinking and everything working fine). The mechanic told me he thought he could fix the AT control unit but found out that it was beyond repair..... I just want to know before I go on ahead to change the AT control unit if that's what is causing the D4 indicator to flash.

tech8

The Transmission Control Unit (TCU) is commonly the culprit for your generation Accord. If you do a Search with 'Archive content' selected, you will find many posts. Is is relatively easy to try to repair or replace that unit.

Here is a link:

http://techauto.tripod.com/