Maintanance required light is on.

[JEEPCAPTAIN]

Hello everyone,

I am new to the XJ community, I just bought a '92 Cherokee Sport and I am currently having a maintanace required light come on the dashboard. I don't have an owners manual for it yet, so I don't know how to reset the light.

Also, I took it to AutoZone and had it scanned, and no codes showed up. It has 88K on it so it's probably an idiot light to the dealer. Is there a module I need to replace on it?

Any help would be great.

[gregmondro]

92 is OBD1, Autozone can only scan for OBD2 codes (95+ vehicles).

You can check the codes by doing the key trick. Directions are here along with the codes.

http://www.nagca.com/grandtech/troubleshootcodes.htm

Even though the above is for a GC, the XJs are the same.

[Lou]

'MAINT REQ' is an odometer-count based reminder to replace the O2 sensor.

88K sounds about right. A bad O2 will affected mileage, and emissions

[JEEPCAPTAIN]

Wouldn't the scan at autozone tell me I had a bad O2 sensor at least? It came up as nothing.
Someone told me its a "timing module" under the dashboard that needs to be replaced for a few bucks. Maybe I should replace the O2 sensor anyway. Thanks for the help. I hate idiot lights. There is nothing wrong with it performace wise.

[jneary]

its a reminder to go and make sure the emissions components are functioning properly. the only way to turn it off is to go to the dealer and they need to do it with their scan tool.

[5-90]

Your HEGO sensor isn't necessarily bad - it's just a "reminder" timer.

Spec life of a HEGO sensor is 80K miles - but I've got an 88 with 247Kmiles on it, and the original HEGO is still in place. I may change it soon - it will probably push me back up to about 20mpg (changing the clutch and transmission are also going to help - I've had input bearing trouble on the Peugeot, and the throw-out bearing has also been causing trouble...)

However, while HEGO sensors are spec'd for 80Kmiles, I've heard of them routinely lasting some 150Kmiles, often more.

5-90

[Slo-Sho]

I have learned that the timer module is powered whenever the ignition is on. It is a transparent plastic box with many plastic gears inside (freakin ingenious) and looks to be an electric analog timer. It is located where your right knee would be on the other side of the lower dash panel. It can't be reset and there was an actual part # for it, $30 IIRC a few years ago. Who knows you might get lucky, I unplugged mine.

[XgeekstarX]

maintenance required light comes on at certain mileage intervals. just use a good scan tool (i.e. snapon) to reset the light.

[misterjeeper]

However, If you are a backyard mechanic, and dont want to pay craploads of money to have someone reset it for you...Undo the 4screws to get the dash bezel off, then the 2 screws surrounding the warning lights, and unplug the bulb

[jneary]

I have learned that the timer module is powered whenever the ignition is on. It is a transparent plastic box with many plastic gears inside (freakin ingenious) and looks to be an electric analog timer. It is located where your right knee would be on the other side of the lower dash panel. It can't be reset and there was an actual part # for it, $30 IIRC a few years ago. Who knows you might get lucky, I unplugged mine.
there is no timer on the '92. it is computer controlled

[JEEPCAPTAIN]

However, If you are a backyard mechanic, and dont want to pay craploads of money to have someone reset it for you...Undo the 4screws to get the dash bezel off, then the 2 screws surrounding the warning lights, and unplug the bulb


This is what I did. The Jeep is perfectly fine now.