Oil level sensor light question. (1 Viewer)

[drlaytn]

I have a 94 FJ80 that has an oil level sensor light on the speedo ( the orange oil can) that won’t turn off. I unplugged the sensor connection at the oil pan and the light is still on. It seems like pulling the plug would make the light go out?. I’ve changed speedometers ( I have 3… don’t ask and that doesn’t do it either. Any ideas where I should look next? The oil level is fine. Torfab just put a new 1FZ in two weeks ago. It’s a thing of beauty. The light was coming on before the new motor.. so I don’t think that’s the issue.

Next step might be to pull the lightbulb out of the dash, but I’d like to fix it right.

 

[Fj80oregon]

Replace the oil level sensor.

 

[Marvelicious]

Someone correct me if I'm wrong, but I suspect that it fails on... that is, if you've got a bad switch, or it's unplugged or the wire is broken somewhere, you get the light. Should be a pretty basic multi-meter troubleshooting operation, if you're versed in that sort of thing. If not, there should be general tutorials that explain it better than I do.

 

[NeverFinis]

According to the EWD, the bulb should not illuminate if you disconnect your oil level sensor from the harness. There would be no path to ground when you do that. You probably have a ground short in your harness. I would look at each side of pin 7 at IH2 to see if either side is grounded.

 

[bryson]

I have bypassed a couple of these, and you have to connect the harness wires together to eliminate the light. I just clip the connector, strip remaining ends, crimp together and heat-shrink. Tie up the pigtail and be done.

 

[voodu3]

X2 on the ground issue. Have you pulled the sensor out to check that it’s not just gummed up? I cleaned mine and it started working properly.

 

[drlaytn]

So… a question, since I flunked out of wiring schemo class…could you point me to where IH2 and pin 7 is?? Is it in the big plug on the left side that sits by the tranny dipstick by the starter? I’m pretty good at working on things with grease and oil, but electrical is a head scratcher. Thanks!

 

[drlaytn]

I haven’t pulled the sensor since logic dictates the light should go off when I pulled the connector to the sensor. I don’t want to dig into my clean new oil pan unless I have to.

 

[NeverFinis]

The 1FZ-FE does tend to have wiring issues in the harness as in bends near the engine intake.

IH2 (or IL2 on a LX450) is a major 17 pin connector behind the glovebox, which I am very familiar with due to the LS Swap I am doing. The glovebox is easy to remove. I colored pin 7 in the pic below. Check to see if it has continuity to ground. It shouldn't with the oil level sensor disconnected.

 

[Kernal]

Was the main engine harness replaced along with the new engine?

 

[mudgudgeon]

Was the main engine harness replaced along with the new engine?

Likewise with the oil level sensor?

If it fails with light on, faulty sensor could well be the issue

 

[drlaytn]

No. Harness was not replaced. Nor was the oil sensor. Torfab re-used the sensor. I do have a new sensor, but I didn’t want to install it yet since pulling the connector didn’t make the light go out. It’d be nice to figure this out, but I guess the biggest thing for me is that I don’t like that light glaring at me from the speedo. I’ll test pin 7 on IH2. I think I’ll plug in the connector to the sensor. If I’m reading NeverFinis right… it should show grounded. If it doesn’t… any ideas where to start looking for a break… or any ideas for a workaround?

Thanks!

 

[NeverFinis]

No. Harness was not replaced. Nor was the oil sensor. Torfab re-used the sensor. I do have a new sensor, but I didn’t want to install it yet since pulling the connector didn’t make the light go out. It’d be nice to figure this out, but I guess the biggest thing for me is that I don’t like that light glaring at me from the speedo. I’ll test pin 7 on IH2. I think I’ll plug in the connector to the sensor. If I’m reading NeverFinis right… it should show grounded. If it doesn’t… any ideas where to start looking for a break… or any ideas for a workaround?

Thanks!

With Oil Level Sensor disconnected, you should NOT see GND on either side of IH2 -Pin 7. If you do, you have a short. This is abnormal.

With Oil Level Sensor connected and low oil level, you should see GND on engine side of IH2 -Pin 7. This is normal.

With Oil Level Sensor connected and normal oil level, you should NOT see GND on engine side of IH2 -Pin 7. This is normal.

I would look at the harness where it bends by the intake, I believe near the EGR. I think it can get cooked there.

 

[bryson]

Pulling the connector will NOT make the light go off, nor should it.

Replace or clean the sensor if you want to keep the low level indicator functional, or connect the 2 wires at the plug to bypass it. Bypassing does not interfere with any other function of the vehicle, and it WILL turn off your light. There is a chance that you do still have a wiring issue, but it's not a failure I've seen or heard of.

 

[bryson]

Don't overthink it - temporarily bypass the sensor by unplugging it and jumping the two wires on the harness end together. If the light goes out, your wiring is fine.

 

[mudgudgeon]

Don't overthink it - temporarily bypass the sensor by unplugging it and jumping the two wires on the harness end together. If the light goes out, your wiring is fine.

Path of least resistance right there!

This will confirm if it's sensor or wiring.

Changing the sensor itself is easy, 4 little bolts, and an oring seal. Just be careful not to offer tighten the bolts.
Clean around it first.

Caveat is, i haven't changed one in the vehicle

 

[drlaytn]

Thanks for all of the input. I’ll connect the wires at the connector and see if the light goes out and work back from there.
I had Tor get rid of the EGR. I think that was the cause of 2 blown head gaskets in the #6 cylinder ( over the course of 20 years). I’ve owned my 94 FJ 80 since 97… I’ve had it longer than my youngest daughter it was close to 300k when the head gasket blew, so I decided to have Torfab put a brand new short block and a rebuilt head…injectors…basically a new motor.. while it was there I had them rebuild the knuckles, install new axles and Birfs, new brake lines and a new power steering pump. Now I’m getting it in shape for the next 30 years! I told my kids they can bury me in it, but they’ll probably toss me in the pit and keep the Cruiser