what does MAINT REQD indicator signify?

Backstory here is that I swapped all my interior incandescent bulbs with LEDs, and a couple of the indicator lights now have a slight glow. One of them is the washer fluid level indicator, which always glows no matter how much fluid is in the tank, and still glows even after I swapped the tank with a spare. Debugging suggests that this one glows from a residual signal that is picked up from the reservoir resistor or something (don't have my books).

The other one is the MAINT REQD light, which also has a slight glow on it. I'm not sure if this is indicating a problem condition or if it is just another voltage leak of some kind. So first question, what does the MAINT REQD indicator signify that is different from the CHECK ENGINE indicator? BTW I don't have my jeep or any of my books here (they are all at the garage where I am painting it), so at this point it's just a conversation item.

Thanks

usuallly you're due for some kind major maint.. 30K... 60K

nice.... google'd it up finally and you're right. I'll try getting one of my mechanics to reset the timer and if that doesn't clear the residual voltage then I'll just pull the LED since it serves no purpose but to nag.

ehall said:

nice.... google'd it up finally and you're right. I'll try getting one of my mechanics to reset the timer and if that doesn't clear the residual voltage then I'll just pull the LED since it serves no purpose but to nag.

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Pull the timer module while you're about it - that's the usual fix for such. I think it's down by the fuse panel near your left knee, but I won't swear to it (there are others here who will know better than I...)

Yup, behind the bottom panel, by left knee.

update... RENIX and some YJ have the module, but 91 XJ uses the ECM to track mileage and there is no module.

also I went to one of my shops today and we tried to reset the timer with the Snap-On scanner but it did not reset. I will try again at another shop that is a little better versed in these things and if it still doesn't reset I'll pull the plug or maybe snip the ECM signal wire

ehall said:

update... RENIX and some YJ have the module, but 91 XJ uses the ECM to track mileage and there is no module.

also I went to one of my shops today and we tried to reset the timer with the Snap-On scanner but it did not reset. I will try again at another shop that is a little better versed in these things and if it still doesn't reset I'll pull the plug or maybe snip the ECM signal wire

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Your problem is that you most likely do not have a "maintenance required" issue, so there is no resetting to be done.

When converting to LEDs you can end up with multiple resistance issues, like the turn signal indicator not flashing when a regular bulb is burned out.

I believe you are going to have to do some research on that issue and probably end up splicing in some Radio Shack resistors.

Read through these notes: http://www.superbrightleds.com/carbulb-notes.htm

I can tell when it's resistance because of the brightness--the LEDs that have full voltage are fully bright, while the ones with residual noise only have a faint glow. The CHECK ENGINE is that way and I have to fix that one for sure. MAINT REQD is full glow at key on and stays that way (so is the washer fluid light) both of which had their bulbs pulled by the PO.

the maint reqd light must be reset at the dealer, if you really want, you can pull the bulb out. it only serves as a reminder to have your emissions components checked. its not a big deal in a pre OBD2 jeep.

ehall said:

I can tell when it's resistance because of the brightness--the LEDs that have full voltage are fully bright, while the ones with residual noise only have a faint glow. The CHECK ENGINE is that way and I have to fix that one for sure. MAINT REQD is full glow at key on and stays that way (so is the washer fluid light) both of which had their bulbs pulled by the PO.

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Your original post said the Maintenance Reqd light had a slight glow, apparently things have changed.

Grabbed this from jeepforum.com post:

"On the post-Renix and pre-OBD-II XJ's, the "maintenance required" light is driven by the ECU directly. There is NO separate timer like there was on the Renix model. It's designed to come on at 82,500 miles, and basically is an alert to have the O2 sensor changed.

The ONLY way this light can be reset is with the special DRB scanner from Chrysler. The alternative most owners take is to just PULL THE BULB from the warning cluster in the instrument panel."

Hope you get it worked out.

I just double checked and it is indeed residual voltage on all of them--swapping incandescent bulbs into the sockets makes them all go out. So it would appear the Snap-On scanner worked to clear the MAINT REQD.

Very odd that MAINT REQD and WASHER fluid bulbs were still full brightness though. I have to look at that more.

ehall said:

. . . and WASHER fluid bulbs were still full brightness though. I have to look at that more.

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Since the washer light was removed by the P.O. I would guess that level switch in the bottle is messed up. Try unplugging it at the bottle and see what happens when you short the ends together.

I replaced the bottle a while ago as first try. With incandescent it passes basic tests as expected, which is off when bottle is full and on when leads are touched together (I don't know if it works when bottle is empty or low). I did have to rap it with a screwdriver once for one of the "full" tests.

The LED always shows some brightness. Presumably there is always some residual voltage which the natural resistance of the incandescent filament blocks out.

The "full brightness" issue with the LED seems to be an artifact of having the label screen off. The lights are noticeably more dim when that is on.