Bcm/skrem problem

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

The old lady was driving and all the gauges quit and no bus popped up on odometer. Messed around with it and battery tested bad so I got new one and didn't fix. So I took to dealer and they said the battery I was gave was wrong one. Put right battery in and problem fixed. A week later it did it again. It starts up and then no bus pops up and it shuts down. I found a ground on fender that was corroded, so I cleaned and fixed problem for 2 months and it did it again. Now it won't crank and mechanic says he can't communicate with bcm and skrem. He replaced skrem and still can't communicate with them. He says he is leaning toward bcm being bad. Any thoughts?

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

I forgot to mention that when it messes up the key fobs quit working.

papaindigo · **Posted:** Tue Sep 10, 2013 8:54 am

Thoughts for what they are worth:
1. what battery did you get that was "wrong" and what battery do you have that's apparently "right"? Any group 34 or 34R battery with 750cca+ is fine; certainly doesn't have to be an Optima red top, probably better if it isn't given more recent Optima quality or lack thereof.
2. battery fixed the problem for a while then fixing a corroded ground fixed the problem for a while.
3. "no bus" message per FSM is lost communication and failure of remote key fobs at the same time would make sense.

Given 2 and 3 plus what the FSM says about "no bus" I'd be looking for a wiring, connectors included, problem before I'd be replacing modules.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

The battery was like 500cca and now we have a 800cca. The mechanic said those 2 modules were the only ones have problems and he didn't find any wiring or connection problems. That's why he replaced the skrem.

papaindigo · **Posted:** Tue Sep 10, 2013 10:33 am

Definitely needed the more cca battery. I'll defer to others on the module vs. wiring issue as I'm by no means an expert on today's auto electrics.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

Me either. That's why I took it to a mechanic and still didn't accomplish any thing. I talked to mechanic and he said he tried MODIS, T-300 and DRB3. None of them would communicate with the skrem or bcm.

papaindigo · **Posted:** Tue Sep 10, 2013 4:52 pm

I'm by no means an expert of what tools will communicate with either 05 or 06 computer systems or which systems but I will observe there seems to be a general consensus that only DCJ dealer or equivalent ones will do the job for all systems given the kludge of the computer systems.

Slightly long winded way of hinting that lack of communication may be the fault of the mechanic's tool not the module he cannot read. Suggest you PM/email Sir Sam who knows more about this issue than I do.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

I brought that up to him and he said the stuff he had would. Kinda wondering tho if he is wrong. I talked to dealer and since I paid them to diagnose it and what they said didn't fix it. They with diagnose it for free this time.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

Dealership says the PCM has fault codes and needs replaced. They quoted me 1100.

papaindigo · **Posted:** Mon Sep 16, 2013 11:00 am

That sounds odd so:
1. where are you physically located. Maybe there is forum help nearby
2. what do they mean by PCM? You have a body control module and the key fob receiver is associated with it and you have an engine control module. They might be referring to the latter by why that would result in a key fob failure to like unlock doors I have no clue. In any case what specific fault codes? Just because codes are stored does not mean the module is bad, in fact one of its jobs is to store fault codes.
3. I don't know the cost of either module but I do now from personal experience that the physical action of replacing the engine control module is like 30 minutes labor although they would have to program it to the vehicle's VIN but that typically costs like $100 at a dealer.

Thoughts:
a. given what you did that made the problem go away for a while I still think you have a "wiring" problem not a module problem but I'm certainly no expert in this area.
b. if in fact you need a "new" engine control module I'd check with like GDE (ID parts too although they don't list the module). I bet you can get a new/used module with a GDE tune for a lot less than $1,100

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

I talked to a local place and they can rebuild it for 200. I'll give GDE a call

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

Picked up jeep today since they were done diagnosing it. On the paper they gave me it says checked DTC and found p1001 which is a internal PCM failure and was unable to reflash and needs new PCM.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

Only thing I can find about that code is ignition key off timer to fast.

AlamoLiberty · **Joined:** Tue Mar 22, 2011 11:30 pm **Posts:** 9

It sounds like a bad ground to me. Either way, I suggest you call Keith at GDE. He should be able to help you determine whether the module is bad. I am having some similar electrical issues with my 05 Liberty. Another suggestion is to buy a cheap code reader or stop by Advance Auto or a local shop to get the codes read for free. I bought three cheap code readers online for $20 each. I keep one in each car. They have been VERY USEFUL. I also have a really nice one that I bought from GDE when I bought the Hot Tune.
My 05 is down right now as I cannot get it to start. It will crank but it will not start. My fuel gauge reads empty although it is full. My oil light comes on. The key fob security light flashes then remains lit. The code reader (from GDE) was also having intermittent connection issues to the ECM. I initially diagnosed the ECM as failed. I sent it to GDE for a reflash and testing. It turns out the ECM is fine. Keith explained that the ECM is pretty solid and is similar to a light bulb in that it either works properly or not at all.
Tomorrow, I will be searching for more corroded ground wires on my 05 Liberty diesel. I have already found and cleaned two. My 2007 2500 LWB 5.9 Cummins diesel caused two batteries to boil and massively leak acid. We found that was caused by a combination of bad grounds (corroded) and bad battery cables. Once we solved these issues, my transmission and electrical issues vanished (on the truck).
I hope you solve your Jeep issue. Please keep us updated. Good luck.

AlamoLiberty · **Joined:** Tue Mar 22, 2011 11:30 pm **Posts:** 9

Before you replace your BCM, you should probably check out a few other things.

1) As I mentioned earlier, check your grounds. As I recall, there are four major grounds to examine.
2) Research ignition key issues on Lost Jeeps. It could be a simple part that does not need to be reprogrammed. I mention this as the dealer mentioned this ignition timing issue in your notes and I have heard of key cylinder issues causing similar problems.
3) Check on your Front Control Module (FCM). The 05 Liberty 2.8 has a FCM located just behind and below the drivers side headlight. It is square and about 5x5. It is silver colored. It is mounted on a black bracket. You may need to remove your battery and battery trey to access it. Check the connector for corrosion. Note: The 06 Liberty DOES NOT have this module. Ask me how I know... This module is sometimes refereed to as a "Gateway Control Module".

Take a look at these two links:

viewtopic.php?f=5&t=75792&hilit=Front+Control+Module+FCM+

viewtopic.php?f=5&t=76195&hilit=gateway+module

Please update the forum with you progress and final solution.

Good Luck.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

The ECM didn't need rebuilt but the guy that checked it said he could the dealer had been in there trying to reflash and had messed up the tuning. I cleaned The ground by the gateway module before and that seemed to fix problem for awhile. I cut end off and stripped wires back so I could put new end on and the wires look a little black and corroded.

99sportcummins · **Joined:** Tue Apr 05, 2011 10:34 pm **Posts:** 31

I think I found the problem. I started checking the wiring harness and the part that runs across the top of the engine inside the black plastic shield is hard and not flexible. It acts like someone glued it together. I tried pulling the wires apart and I'm pulling the insulation off on some parts. I assume they got hot and melted together

Bcm/skrem problem

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