anyone have an FCM or ECM?

JDaPP · **Posted:** Sun Nov 02, 2014 7:18 pm

Trying to chase down what is causing my wif ,failed fuel gauge, and low oil pressure light. It has been recommended that I try fcm, but I hate to spend the money at the dealer if someone has one they are trying to get rid of or one that I could throw in to see if that is really the problem. Already tried eBay and local pick and pull... Thanks

Maver1ck · **Posted:** Sun Nov 02, 2014 10:40 pm

my jeep is going now if you like i will sell the new one that i have

ordered mine through here this week for $206:

http://www.tascaparts.com/oe-mopar/5604 ... 56044599AF

gmctd · **Posted:** Mon Nov 03, 2014 2:29 pm

Pull the battery to get to the FCM beneath the battery box - disconnect the connectors, pull the FCM for a scrutinary inspection, noting the over-all condition of the module, then closer scrutiny of the contacts in the module and connectors - you will be looking for signs of corrosion\oxidation which prevents circuit connection - in some instances, burnishing (scraping) the contacts to remove the corrosion will resume module functions - sometimes merely removing-replacing the connectors can burnish lightly-oxidized contacts to resume operation - a coating of clean petroleum jelly or silicone contact grease can prevent further corrosion and failures - the jelly and grease are excellent insulators which allow circuit contact - has been used extensively in CORVETTE and CADILLAC\BUICK ECM systems, tubes available in the parts department

JDaPP · **Posted:** Mon Nov 03, 2014 4:16 pm

Unfortunately I tried that and it didn't work :-(

. I am actually on the fence right now as my issue matches
Paqclan
viewtopic.php?f=5&t=75792

So talking with Keith I was leaning towards FCM, Paqclan said FCM did not fix his problem so I am actually leaning towards new ECM, I just hate spending the money...

So if anyone has an ECM I am interested in that as well.

papaindigo · **Posted:** Mon Nov 03, 2014 4:37 pm

All I can offer:
1. FCM probably does not involve programming so there is a decent chance you can score a used one on like http://www.uneedapart.com/
2. ECM will require programming, which is not free, at least to your VIN, Have you asked Keith about reprogramming yours or if he has a loaner you could like rent to see if it helped before springing for a new one?

JDaPP · **Posted:** Mon Nov 03, 2014 4:56 pm

Keith said he can reprogram the new one, but did not have any for sale. I did not ask about a loner for rent, but he didn't offer one either so I didn't want to be rude and impose. I will check out the parts link and see what I can find. I appreciate all the help and please keep it coming.

gmctd · **Posted:** Mon Nov 03, 2014 5:10 pm

Gassers have Powertrain Control Modules - Diesels have Engine Control Modules (or Engine Management Computers) with Transmission Control Modules - all require some reprogramming when swapping between vehicles

What item is being referred to here as a "PCM" that does not require programming?

The Forward Control Module, also referred to as the Gateway module, does not require reprogramming when swapping

JDaPP · **Posted:** Mon Nov 03, 2014 5:25 pm

For the ecm I have found 2 part numbers searching for the ECM. 56044562ad and 56044562ba. Is there any difference?

For reference the one in there now is 56044562cb

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

part number is good, look for the following suffixes only: BE, BF, CA, CB, CC, CD, CE or CF

The others will not work well.

JDaPP · **Posted:** Mon Nov 03, 2014 9:15 pm

Figures, I had found a deal on 56044562ad

RockyMountainYote · **Joined:** Sun Oct 20, 2013 8:32 pm **Posts:** 77

I have a CRD ECM, I'll post the part # when I go to my shop tomorrow

JDaPP · **Posted:** Wed Nov 05, 2014 4:32 pm

RockyMountainYote wrote:

I have a CRD ECM, I'll post the part # when I go to my shop tomorrow

Definitely interested, PM sent.

gmctd · **Posted:** Thu Nov 06, 2014 9:30 pm

Try this----------

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

I'll be back.......................

As I tho't, 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

Maver1ck · **Posted:** Fri Nov 07, 2014 12:24 am

At last we have solved the mystery on "MY" Jeep. We put a new oil sending unit in a few weeks ago and it ran fine. Recently 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 someone else as I have spent way to much time chasing gremlins on my Jeep. :BANANA:

JDaPP · **Posted:** Fri Nov 07, 2014 8:44 am

#1 thank you very much for posting this. I believe I have the same/similar problem. I recently clipped a wire(s) while working on my bumper (brown with white stripe, black (could be brown) with green stripe, and just brown). After clipping the wires I had an oil pressure light, I repaired the wires and that light went away. Two weeks later I got the Water in fuel, fuel level sender, oil pressure, no A/C. I already rechecked the wires to include soldering them so that should not be the issue. Other things that I have worked on since August was the blower motor resistor (upgraded to sebring model) and I changed the oil pressure sensor underneath the jeep.

I am not the best mechanic so I may need some help on this one. Understand you ran the wires to determine voltage. I don't have a voltage meter, so I will need to go get one, any recommendations? I have looked at the FCM, when you say the out supply which one are you referring to? Final question is did you replace the sensor to fix the problem or the connector? Sorry for all the questions I am a visual guy so I am trying to picture the issue in my head. I will download the FSM to try and find all the sensors. Again thank you for posting this.

gmctd · **Posted:** Fri Nov 07, 2014 11:53 am

HARBOR FREIGHT offers several Digital Volt Meters DVM ranging in price from less than $5 to ~$70 - any of these will serve to help you troubleshoot your problems - choose wisely, grasshopper...................

HARBOR FREIGHT stores are located in most larger towns and cities - look'em up

Good start to download the FSM, with it's diagrams and schematics

JDaPP · **Posted:** Sat Nov 08, 2014 8:29 am

If you are having this problem check this thread as well viewtopic.php?f=5&t=80457&start=0

anyone have an FCM or ECM?

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