I have a 1990 Dodge Ram D-250 5.9l V8 3 spd auto, there is a light that says maint reqd. What does this mean? I just put a new ecu in it because the old one was causing it not to charge, don't know if that would effect it. The truck has been sitting for a couple months if that helps. Anyone got an answer?

 

the maintenance required light is a warning from the ECU that something might be wrong - and it gives a code to a special tool and each code corresponds to a certain issue.

ive never changed an ECU before, BUT i do know that when they are disconnected from the battery they will give a code that sais "ECU has been disconnected from battery"

anyhow thats just a possibility. if the light doesnt go away or the truck is running wierd take it in to get the code read. You can also flick the keys on-off-on 3 times and count the times "maintenance required" flashes long and short (after it flashes a preset number of times which i forget, you can find it in a Chiltons or even google) - but if you arent really used to that sort of thing just bring it in

 

better still, take it back to the guy who put the ECU in and ask him to pull the code.

if there isnt really an issue, he shouldnt charge you since he should have cleared the ECU before giving it back. If you take it to any other shop, theyll charge you.

 

Thanks for the quick responses, it seems to be running fine, so I don't think it is a current code. I will check it out tomorrow and figure out what code it is and fix it from there. Thanks again.