That requires a scan tool.
Because it's not just an oil change reminder as in a lot of other cars, it is a longer term reminder for service of the emissions system (i.e. O2 sensor,EGR, Evaportive Canister, etc.) . You can purchase scanners that will connect to OBD1 such as yours and check the emission parameters and reset the light yourself. Follow the instructions provided with your scanner.
A scan tool is required.
That requires a scan tool.
Just found out that it must be reset at the dealership with a diagnostic computer
you need the proper scan tool to reset it or take it to a certified mechanic or you can just remove it all together but you must do the required maintenance.
You can reset the light by disconnecting the battery cable for about 5 minutes, then reconnect. You will need a scan tool.
I believ that a special tool is required it might be cheaper to have it done than to buy the tool
Plymouth made a Voyager minivan from 1990 to 2000.
Disconnect the battery wait a minute then reconnect this should turn the light off.
You should solve the issue that caused the warning first or you may be in for trouble down the road. You can pull the codes at most auto parts stores or a mechanic can do it for you.That being said, if you pull the battery and turn the key to ON to discharge the power that should reset the light. If it returns immediately then you still have a problem.Also see:How_do_you_reset_the_Maintenance_Required_lamp_in_a_1994_Mitsubishi_Montero
how to reset oil timing on 1990 toyota
On a 1990 Plymouth Voyager 3.0, the water pump is located behind the timing cover. The timing belt is what drives the water pump.
take it in