oil level sensor

03Alerosil · 08-26-2016, 09:25 AM

Hey,
I'm having intermittent issues with my oil level sensor. It comes on occasionally on start up. So when I was underneath it last night, changing my oil, I used my Fluke meter and did a little circuit testing. My sensor has 3 ohms sitting on ramps with a full pan of oil. I figured that was ok. After I cleaned all the oil off the connector and the wiring for the oil level sensor with some cleaner. I got a reading of 3.964 Kilo-Ohms. Now in my mind that is way too high. I looked at a schematic for it on some repair software I have. I saw that the brown wire runs to the PCM and the black/white wire runs to a ground at the front of the starter. So my question is has anyone ran into a issue with the wiring for that sensor? I haven't checked the ground yet but it should be ok as I replaced the starter last year and cleaned every wire that was around it. I pulled on the wires a little in different places checked for a broken or almost broken wire and couldn't find anything. I checked until it goes into the main harness.

Thanks

oh and it's a 2003 with a 3.4. 181,000 on it.

sleepyalero · 08-26-2016, 11:34 AM

A good "wire" should be .1 ohms.

03Alerosil · 08-27-2016, 07:01 AM

I know that sleepy. I'd even accept a few ohms as it runs into the pcm and when I was testing it was probably tracing a few circuits thanks to splice packs. I just don't know if it's the PCM or wiring. I have had this issue where my fans do not turn on unless I turn the A/C or defrost on. I have to drive around with either one turned on. Taking it's toll on compressor though, it makes a little noise.

Shiwnath · 08-27-2016, 09:10 AM

If I remember correctly, the oil pressure sensor is just a simple on/off switch. When the oil pressure switch doesn't see enough pressure, it causes a break in the 5V line and sends a low pressure signal. When the oil pressure is OK, the pressure switch is "pressed" by the pressure and completes the circuit.

Theoretically, with the engine running you could disconnect the oil pressure sensor and check for electrical continuity between the contacts on the sensor to verify it's working. Whether or not that's easy with the engine on is a different story. Don't worry about disconnecting the sensor with the engine running... Guys with 3500 swaps can't even plug a oil pressure sensor in without modification.

03Alerosil · 08-27-2016, 05:53 PM

Good advice but I'm having issues with the oil level sensor, not the pressure sensor

Shiwnath · 08-27-2016, 07:51 PM

Quote:

Originally Posted by 03Alerosil

Good advice but I'm having issues with the oil level sensor, not the pressure sensor

They're one and the same. Oil level is typically measured by pressure.

Also just thought of something as well... You could go to a junk yard, find a scrap car with a 3400, cut the oil pressure sensor plug with enough wiring to check for continuity if you cant get to it easily.

03Alerosil · 08-28-2016, 08:34 AM

I wasn't aware of that. Thanks for the info. I may have to check the local junkyards. I may also test one next time a car with a 3400 rolls into the shop. I want to be sure it's the pigtail and not something else before I go and replace it. Like I said, it's very random.