I pulled the dash on my son's 1989 D100 to swap what I had hoped was a bad oil pressure gauge (it wasn't) and to replace the gear position indicator. I noticed there were a number of missing bulbs, which I replaced from a salvage yard cluster.

Now I have a light saying 'MAINT REQUIRED.'. I will assume this is just one of those idiot lamps that come on at a scheduled point every so often to prompt you to change your oil or sparkplugs.

My question is how can I turn the silly thing off, or will it just go out on it's own (not likely I bet).

 

The first computer ODB1 scan tool or just try pulling the positive off the battery.

 

I left the battery cable off overnight and no change this morning. I also looked behind the glove box for some type of control box but did not see anything there. I also checked under the dash all the way to the right around the headlight switch and did not see anything there either.

Although I do not like the idea of doing so, unless some one comes up with another idea, I guess I will just pull the dash and remove the bulb.

Let me know any ofther ideas!
Thanks all!

 

Remove the negative and positive cable from the battery and clip them together. If they wont reach use jumpers. The PCM has a self powered memory in case you lose a battery charge. When you touch both together it dumps the memory. This works for OBD2 as well. Leave the two connected for at least 5 minutes.

 

I rechecked and did finally locate the 'Emission Maintenance Reminder' module behind the glove box mounted on the upper firewall on the '89 D100. It is about 4x6x1 with about 20 wires leading into it. Unfortunatel as this is an '89 it does not have the magic button to push to reset as the '88 does.

 

@PK1, I just saw your post and have pulled the cables and used a jumper to connect the two. I will post back and let you know how it works for this case.

 

Oh well, I did as PK1 suggested and clipped the two cables together and left it that way for 30 minutes and the *&^ light was still on. At this point I just reached behind the dash and removed the bulb - problem solved (more or less). It is not the way I like to operate, but the smog air pump does not have a belt on it anyway.

 

Its not from the pump. It would reset.

Does your reminder box open on the side? Look closely but it may have a small crack. It will take a 9 volt battery. You can replace the battery. The voltage keeps the light off. I believe it take a jewelers driver or paper clip to pop the cover..

 

I did find the module mounted on the inside firewall behind the glovebox. I disconnected it and left it off for a while. I also was able to start the motor with the unit disconnected and it seemed to operate OK. Nothing changed on the actual light. I also took the module loose from the firewall and checked it out fairly completely, but was not able to see any way to open it up, or see any sort of opening or button. From what I can see, the '89 D100 is a bit different from the '88s.