WIF, Oil, Fuel gauge and lights issue

spud68 · **Posted:** Wed Jul 29, 2015 10:59 am

Hello all, I have an issue I cant track down.

A few weeks ago my Oil light came on and I replaced the oil sensor and it went out and worked perfect, until yesterday.

yesterday the Water in Fuel, Oil, and fuel gauge lights all came on at the same time and the fuel gauge quit working.

I read on another thread in this forum to try disconnecting the sensors one at a time to see where the problem could be and when I disconnected the Oil sensor, the other lights went out and only the oil light remains. Could this sensor have went bad so quickly or is there something else going on?

The Oil level is correct and the oil looks normal. and the little tractor runs perfect!

Thanks in advance for any help you guys can provide.

Teddy

olypopper · **Posted:** Thu Jul 30, 2015 4:10 pm

It would seem to me that you need to track down an accurate wiring schematic for your model and see what all of those lights share in common. Since I am not intricately familiar with how the electrical systems on these Libby's work, I could assume that either you have a grounded wire or an open somewhere that is causing your condition.

GreenDieselEngineering · **Joined:** Sun Jun 07, 2009 5:10 pm **Posts:** 1111

Check the gateway module behind the front left headlamp. It is 6"x6"x1" and silver. It can get corroded and have a bad connection. All those signals you lost are broadcast by the CAN bus and the gateway controls the bus.

Maver1ck · **Posted:** Thu Jul 30, 2015 10:42 pm

I had the same problem when I put a new oil sending unit in and it ran fine. Then it shorted out the 5 volt reference of the FCM. So I recommend if anyone is having a similar problem (Water in fuel, fuel level sender, oil pressure, AC High Pressure/Low pressure). Check for 5 volt sensor supply out of the FCM pin #16 (brown and light green wire). If it reads anything less than 5v start at the: 5v Brown/light green line on the A/C pressure Transducer, FCM (Gateway module)controls, remove the connectors at the following locations; the fuel level sensor, low oil pressure light, A/C pressure sensor, generator/alternator field control, and Water In Fuel Sensor. Hope this helps.

Maver1ck · **Posted:** Thu Jul 30, 2015 10:50 pm

This was posted from another member that helped me find out my problem,

While measuring the +5v line, unplug each of the affected sensors one at a time incl the oil pressure sensor(the low-oil lamp is +12v. so that won't affect the test) - the +5v should return after you disconnect the failed sensor

Alternately, first unplug all the associated sensors then measure the +5v line to see if it is good - if not good with all sensors unplugged, the problem is in the FCM\Gateway, it's connector, or the wiring harness or connectors

Also the Front Control Module info, wiring, and connection is in the '05 KJ Diesel Powertrain Manual, but not the KJ Service Manual, which is for the gasoline-fueled versions - both versions are available on the Colorado website - look in the FSM INDEX for specifics direction

spud68 · **Posted:** Fri Jul 31, 2015 8:50 am

Thanks a bunch for the help! How did you fix you problem Maver1ck? did you have to replace the FCM? I've got a lot of work this morning I hope I can track it down. As always this place is the best source for all things CRD...

Teddy

Maver1ck · **Posted:** Mon Aug 10, 2015 10:05 am

Once I knew it was the oil sensor, I replaced it 2 times, and each time it worked for awhile, so I just discounted it permanently. By the time the oil light comes on in our CRD the damage is already done, due to the location of the sensor. So now I have the oil light on all the time, but at least all the other problems went away.

spud68 · **Posted:** Thu Aug 13, 2015 11:11 am

I wanted to offer an update on my issues and ask another question.

1. I replaced the Gateway control module because I thought that had to be the problem. ( When i took the old one off the boost hose had worn a hole in the corner of the outer case. I could see thru to the electronics board)

2. That didn't fix it. I unplugged the Oil sending unit and the lights went off (except the Oil dummy light)

3. So I replaced the Oil sender unit AGAIN. (other one was replaced a couple of weeks ago) and it worked. all lights are off and everything works.

4. 2 days after replacing the new oil sensor, ALL the lights are back on again. I unplug the oil sensor and all lights go off again (except the oil light).

Is there something I'm missing or could the sensor be bad AGAIN or am I getting the wrong sensor? the Oil level is good and the Jeep runs perfect. The question is what are the risks to driving the jeep with the light on? and could I just install an after market oil pressure gauge and be good? What pressure should I be seeing on the gauge?

Thanks a bunch for all your help!

Teddy

WIF, Oil, Fuel gauge and lights issue

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