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"Service Required" light on

I have a 1992 Jeep Wrangler Renegade with 120,000 miles on it. At 60,000 miles the Service Required light came on. In the manual it said this is normal and an O2 sensor should be replaced. Being in the auto field for 35 years I did just that. I had to go to the dealer so they cold reset the light since my year Wrangler does not have a connector under the dash. The light is on again at 120,000 miles which the manual says is programmed into the vehicle. Is there a way I can reprogram the light without going to the dealer?

Thanks in advance for your help,


In order to reset the Service Required Light on your Jeep, a Chrysler DRBII tool or a scanner with the same capabilty is required. Had to get one for the wife’s 1990 Jeep to reset the light.


I have found that the dealerships rarely offer this information. The simple fix would be to remove the light but I would never recommend that.

I would…

If you remove the bulb, how will you know if something serious goes wrong?

Besides, if the OP lives in an area with emissions testing, the lack of a working bulb will cause the vehicle to fail the inspection.

I know Caddyman doesn’t like emissions tests, or inspections, and I agree with him, but many of us have to live with these things, and railing against them doesn’t help. We can’t all move to wherever.

You have tried a , let’s say, 10 min battery disconnect? These OBD1 cars are not my favorite but I never found one GM without a “inside the car OBD1 connector” and they did have lower standards to turn the light out, give the battery disconnect a try. You may have to deal with a short “idle re-learn” process that was much prevelant with OBD1 cars.

Are you saying that a 120,000 mile service reminder is programmed into the vehicle (engine computer (MCU)?
Maybe, there really is a trouble which has been discovered by the MCU.

In the manual it says the light will go on at 120,000 miles. It recommends replacing the O2 sensor and then resetting the light. I can’t find a DRB2 scanner to do it.

If I can’t find a DRBII scanner I will try disconnecting the battery.

Disconnect the battery overnight with the headlights on…

The connector is located under the hood near the M/C. In the manual it also says I can disconnect the electrical plug going to the sensor. It says it is under the dash on the right side but I can’t find it.

I will try that tonight. I will let you know what happens. If that doesn’t work I guess you will just have to come to Florida and figure it out.

I can remember in the 80"s with BMW there was a button on a “link” in the speedometer cable circuit (a box that the cable went in and out, when they were still using cables) that you reset at specific service intervals, it also had something to do with a predetermined life span of the 02 sensor, or perhaps it was the EGR flter.

When this 02 sensor thing started (which I think using 02 sensors is a good thing for helping the car run better but a bad thing when they start making trouble for people getting their cars registered) there were some real low replacement intervals published by the manufactures (of the vehicles) SAAB was one for a real low interval at first, 30,000 miles sticks in my mind.

Another emissions component that had a replacement interval, was real expensive, hard to replace, and has gone the way of the Dodo bird are EGR filters. These were a tremendous pain to replace on BMW’s as they were located beneath the intake manifold and that is the worst place to work on a BMW engine, even till this day.

It didn’t work. I ave two choices. 1-take bulb out. 2-go to dealer and pay $42.50.