Tekel

I picked up a '98 and on my first oil change the filter was put on by the hulk so i used other methods to get it off. Ended up breaking my oil pressure sensor. Tried 2 different sensors from 2 different parts stores. Neither fit my plug. I blamed the parts stores until I looked at my plug a little closer. There was some badly wrapped electrical tape. Gave the plug a gentle tug and they came apart. It wasn't the original.

So instead of hoping I can find a 98 in the junk yard, I was hoping I find out what year my plug came from. Both the 98 sensors I got had square prongs. My plug had round.

md21722

My 97 XJ has two round prongs on the sensor. If your 98 is the same, I would put that connector back on and get the right sensor. Dealer sending units tend to work the best.

CCKen

Your '98 is supposed to have two flat pins in the connector and the Oil Pressure Sending Unit. I have no idea where a round pin connector/sending unit would have come from.

The '94-'96 4.0 had a round pin connector/unit. Somewhere in '96 the sending nuit was changed to an OBD II flat-two pin connector/unit.

The parts stores were correct in giving you the flat pin unit. The OEM part number for a '98 Oil Pressure Sending Unit is 56031005.

You may want to check the junk yards for a '97 or '98 XJ and see if you can find a two pin (flat pin) connector and splice it in to your existing wiring and get a '98 sending unit. Some of the parts stores may have the proper connector. Try NAPA and O'reilly auto parts. Starting in '99 XJ's went to a three pin unit/connector.

The wire colors in your XJ should be Gray/Yellow tracer and Brown/Yellow tracer. The GR/YL wire goes to pin 2 of the connector and the BR/YL wire goes to pin 1 of the connector.

Tekel

^ Thank you. Did some searching and it seems no one carries the 98 plug. Came across several places selling the plug similar to what I have.

Am I correct in understanding that this sensor ONLY sends information to the gauge and not the ecu? Since this was functioning correctly before, could I just solder the plug back in and use a sensor from a 96? Junk yards around here are closed on weekends and are only open when i'm working.

Tekel

Or does this look like the right plug for the 98?

md21722

I don't know if the ECU receives the signal or does anything with it like set a code. The 97 has the round pin connector so you can expand your search to include that year if that's the way you go. I just put one on my 97 yesterday.

CCKen

Can't tell about that connector - the pic is too small. If you go O'reilly auto parts and get a BWD Coolant Temperature Connector, part number PT5750, it might fit an Oil Pressure Sending Unit for a '98. If you have the sending unit, go to O'reilly's and see if the Coolant Temp Connector will fit.

Edit: You might try the OP Sendor for your '98 on your ECT connector instead of going to O'Reilly's to try the BWD connector.

CCKen

No, the OP Sending Unit sends its info to the PCM. The PCM puts the info on the CCD Data Bus, and the Instrument Cluster microprocessor picks up that info and changes that CCD Bus data to drive the electromechanical oil pressure gauge.

It's up to you which sending unit and connector you want to use. If the '96 sending unit will work with your OBD II CCD Data Bus - go for it.

Tekel

Thanks. I will check out the Coolant Temp Connector at NAPA. We don't have an O'Reily.

Tekel

Picked up a sensor from a 97 and soldered in the connector. Fit the plug perfect. Here is hoping it isn't sending any different information or a different unit isn't deciphering what it's saying. I also plan on hooking up a mechanic gauge soon to compare the readings.

I went trailing today and pressure seemed a little low when hot.

md21722

Depending on who made that 97 sensor, it may read low.

My 01 XJ has a NAPA sensor that works better than the original dealer one that was dying.

With that success, I put a NAPA sensor on my 97 XJ and found that it reads low. I replaced with a dealer sensor and it seems to work fine so far.

The oil pressure sensors on our Jeeps can fail either reading 80, reading low, or physically breaking or leaking oil. At least that's been my experience.

Glad you are making progress.