EagleXJ

So I was replacing my oil filter the other day and snapped the oil pressure sending unit. I went to advanced auto and got a new one but it didn't work. Took it back and got a different one and this one doesn't work either. I unscrewed it and turned the engine on and oil blew out so the sensor is sure getting oil and I also gave power to the plug and that moved the gauge so the electrical from the sending unit to the panel is good. What could be wrong?!?!?! Please help!!!

dmill89

Go to the dealer and get a sending unit. Aftermarket ones are notorious for failure (often right out of the box). If you can't get to a dealer the NAPA Echlin (their premium brand) is a good second choice.

Also make sure you are getting one for a gauge, there are 2 kinds there is one for an "idiot light" (no gauge) that is an on-off switch that completes a circuit when the pressure hits 0 (or very low) psi, the one for a gauge is a variable resistor and changes resistance based on oil-pressure.

EagleXJ

If I had the wrong sending unit it wouldn't plug in though, right?

EZEARL

Two different types are available. One for an oil pressure gauge and one for an oil pressure light. Could be your getting the wrong one. If not you may be getting faulty units. Save yourself some trouble and get one from a Mopar dealer. My aftermarket one lasted 1 month. I should've taken the advice we're giving you in the first place.

Yep. It'll plug in.

cruiser54

Put power to it?

CCKen

Probably smoked the PCM.

cruiser54

I'm wondering.......

EagleXJ

Sorry, I wasn't very clear; I connected the two contacts in the plug.

cruiser54

I still don't know if that's okay. CCKen will know cuz he has wiring diagrams and is familiar with this new-fangled stuff.

s346k

I don't understand the different types? I bought a replacement for an idiot light (what my jeep did have) and after swapping in a cluster with gauges the oil pressure gauge works fine. ??

EagleXJ

The gauge still moves; when I start the jeep it goes up to 0. It just won't register the oil pressure after that.

sycoglitch

Does it say check gauges??? If it does it doesn't work. Check the wiring too. It's notorious that wiring melts. I got mines from rock auto. Sadly its an airttex but needed something. Also make sure its the 3 wire style and looks identical to the old one cause it may fit but the leads can be different then yours

EagleXJ

The check gauges light is on. So your saying I need a new gauge?

CCKen

First, you want to see if the oil pressure indicator in the instrument cluster is working, then you want to check to see if you are getting a 5 volt reference at the oil pressure sensor connector.

First, perform the instrument cluster actuator test, paying attention to the action of the oil pressure indicator. If the needle cycles through its calibration points the indicator is okay. If just the oil pressure indicator malfunctions and the rest of the indicators cycle through their calibration points, the indicator itself is bad. If all the indicators malfunction, the instrument cluster is bad, or the wiring from the PCM to the cluster is bad.

With the oil pressure sensor connector attached to the sensor do this test:

Instrument Cluster Actuator Test

(1) Begin the test with the ignition switch in the Off position.

(2) Depress the trip odometer reset button.

(3) While holding the trip odometer reset button depressed, turn the ignition switch to the On position, but do not start the engine.

(4) Release the trip odometer reset button.

(5) The gauges should cycle through their ranges, stopping at intermediate readings, going up and going down, at two second intervals. The indicator lamps should cycle on and off.

(6) The instrument cluster will automatically exit the self-diagnostic mode and return to normal operation at the completion of the test, if the ignition switch is turned to the Off position during the test, or if a vehicle speed message indicating that the vehicle is moving is received from the PCM on the CCD data bus during the test.

Next, you will need a digital Voltmeter (cheap at Harbor Freight).

Ignition switch OFF.

Detach the connector from the oil pressure sensor.

Refer to the connector pinout below. The chart next to the connector
pinout shows you the pin cavity numbers, wire colors, and the function
of each pin cavity.

The view in the image below is of the body harness connector as you
are looking at it in your hand, not the sensor.

With your Voltmeter set at 20 VDC,

Turn the ignition switch to RUN, without starting the engine,

Touch the (+) lead of the meter probe to pin cavity 1, and the (-) lead of the meter probe to the battery (-) post.

You should read around 5 Volts on the meter.

Do no other tests at this time.

Do these tests and get back.

sycoglitch

No. I'm saying the pressure sending unit isn't either 1) the right one or 2) isn't wired right. Check the wiring on the harness. You are talkin about the 3 wire connector that screws into the 90 degree piece onto the filter housing right.