[bobp1a1]

Have 2 mechanically solid WK's with electric gremlins. New or even reprogrammed modules are unavailable from Jeep. And 15 yr old modules understandably have issues. I have been searching for software that is affordable and will reprogram salvage modules. AppCar and AlfaOBD do not. Have looked extensively and found nothing other than very expensive business level scan tools that may or may not reprogram FCM/IPM/SCM and maybe PCM.
Gone thru so many websites and detailed threads my head is spinning.

If anyone knows of an affordable DIY option-----Please let me know!
Thanks!
Bob P

 

[paco]

Have 2 mechanically solid WK's with electric gremlins. New or even reprogrammed modules are unavailable from Jeep. And 15 yr old modules understandably have issues. I have been searching for software that is affordable and will reprogram salvage modules. AppCar and AlfaOBD do not. Have looked extensively and found nothing other than very expensive business level scan tools that may or may not reprogram FCM/IPM/SCM and maybe PCM.
Gone thru so many websites and detailed threads my head is spinning.

If anyone knows of an affordable DIY option-----Please let me know!
Thanks!
Bob P

did you try Jscan? This goes with your specific VIN # and it has access to all modules.

 

[bobp1a1]

Thank you sir. On it. Will report.

 

[skjeep]

There is a HUGE difference between read access, change of configurable parameters and reprogramming.

Read is the easiest process and almost any reasonable scanner will do that. Not all uni scanners can access all modules.
Jscan, Appcar, and Alfa can access all modules and can change configurable parameters.
But to reprogram (flash) a module you need way more sophisticated and more $$$ equipment. Plus you need a data source
So you need to have the binary files stored somewhere or you need to dump and modify these form other similar computers
or you need an access to Chrysler/Jeep Tech connect network.
The easiest way (from the user point of view) is OEM WitechII and Micropod tool. But high priced and requires dealer subscription
Or you can use any compatible pass thru programmer. There are modules that are not fully flashable with oem or pass thru.
Or these are flashable only once - when new. You can change/update only variable data portion, not the header. This is to prevent using junkyard modules
Can be done via bench programming. But for that you need other tools, you need to open the module, solder some wires, sometimes desolder a memory
chip or microprocessor.... And all this is far beyond average DIY.

 

[bobp1a1]

SK Jeep. Thank you for straightforward, plain and direct facts.
My understanding then is that there is no DIY solution to reprogram FCM, IPM or ECU by user.
I need to find a service specializing in this. (dealer/shop). ⁴
Or I can try to buy a properly reset module on line.

Thank you again for setting me straight. PS. Just bought JSCAN and appears some good stuff there.

 

[brent_m]

What type of "electrical gremlins" are you dealing with? If there is a technical bulletin that recommends upgrading the software, a dealer should still be able to perform this.

Maybe we can help sort out the specific issues?

 

[bobp1a1]

What type of "electrical gremlins" are you dealing with? If there is a technical bulletin that recommends upgrading the software, a dealer should still be able to perform this.

Maybe we can help sort out the specific issues?

Hi Brent!
Thanks for responding!
The persistent problem is horn sounding. Persistent code is B2336.
Many other codes are thrown occasionally. Have checked and cleaned grounds and connectors at most modules.
Also have strange mileage and fuel capacity measures in PCM.
The horn circuit is good to SCM (SCM and horn button replaced).
Pin 47 on IPM is good to the horn relay.
So my current working theory is that the problem comes from a canbus signal starting at FCM.
FCM is a thousand dollar part new. Not available. Have one from a local junkyard 2005WK but not the right part number. Before I chase other options figured I would look for the ability to program this myself. Figured since I can change parameters, there must be a solution that will let me setup a VIN and whatever else is needed inside the key modules.
Given the world's experience with Chrysler-Daimler TIPM and bus system over the past 15 years, I expect to regularly need to go in and maintain the network.
Of course that does not appear to be something easy to do!!!
Its good to note that in prior models there was a single wire from the horn button to the horn relay. Now the horn button goes to the clockspring to the SCM computer to Canbus to FCM to IPM to horn relay. And the very expensive modules involved are delicate. So I have removed the horn relay and stopped the noise. But I believe whatever is shorted is also damaging other components and causing parasitic draw(new battery) and gremlins.
Any ideas or suggestions appreciated.
Thanks again for listening and offering to help!

Bob P

 

[YouStupidBunny]

I had the same problem with gremlins. Multiple and random codes. Go to Amazon and buy a terminal cleaning kit. Remove your PCM harness. Look for corrosion and scrape it away with your cleaning kit. If your fix isn't at the PCM harness, start removing harnesses looking for corrosion. The TIPM harness would be the next place to look.

 

[bobp1a1]

I had the same problem with gremlins. Multiple and random codes. Go to Amazon and buy a terminal cleaning kit. Remove your PCM harness. Look for corrosion and scrape it away with your cleaning kit. If your fix isn't at the PCM harness, start removing harnesses looking for corrosion. The TIPM harness would be the next place to look.

Thank you YOUSTUPIDBUNNY!!!
I already took your advice and bought the DeOxit kit.
And did actually remove and open the three modules-checking the boards and cleaing everything I could find. Absolutely opened and checked the 4 harnesses going to PCM, two going to IPM and two going to FCM.
Also checked power, ground and canbus continuity at every module I could access. Including shift, cluster, clockspring, ignition and 4 wheel drive box under rear driver seat. Plus the Junction Box and all its connectors. I am sure I missed a couple. But it was a two day job.
Current theory is FCM or IPM for the horn fault and probably spikes that cause occasional massive parasitic drain and maybe corrupted PCM.

On the plus side, its a beautiful, clean Red 2005 with new oil pan and front suspension and drives great. No way am I going to let a dumb "2003 state of the art" network system send this girl to salvage!

Thanks for the advice. I sure hate thinking about completely opening all those harnesses, of course most only contain the damn twisted

I had the same problem with gremlins. Multiple and random codes. Go to Amazon and buy a terminal cleaning kit. Remove your PCM harness. Look for corrosion and scrape it away with your cleaning kit. If your fix isn't at the PCM harness, start removing harnesses looking for corrosion. The TIPM harness would be the next place to look.

PS: I also watched Eric O's Video of same. Amazing catch!

 

[YouStupidBunny]

Yeah, it's a very time consuming process, but think of all the money you're saving doing it yourself. Download a good audiobook and you're multitasking. After you clean the harnesses, make sure you put a little dielectric grease around them to hep prevent future corrosion. Don't go nuts with the stuff. Just a little to create a seal will do. Happy to help!

 

[Road Dog]

The horn switch circuit has always gone through the clockspring and the clockspring does wear out. The canbus protocol has error detection/correction so the modules will only process "good" messages. It is possible for a module to flood the network with messages or have an electrical issue that disables the network. In that case nothing would work. There are canbus monitors out there but I haven't used one yet.

Whenever I hear "electrical gremlins" I think ground issues. There are hundreds of grounds scattered around the vehicle.

 

[bobp1a1]

Horn button and clockspring swapped. And the error persisted even when they were unplugged.
Horns had wires going directly from clockspring to horn relay (no canbus) on earlier jeep models and even later Chrysler vehicles. The additional computers in the circuit eliminate one wire and add expense, complexity and reduced reliability. Just bad engineering.

 

[bobp1a1]

Horn button and clockspring swapped. And the error persisted even when they were unplugged.
Horns had wires going directly from clockspring to horn relay (no canbus) on earlier jeep models and even later Chrysler vehicles. The additional computers in the circuit eliminate one wire and add expense, complexity and reduced reliability. Just bad engineering.

Update!!!!

Have 2 mechanically solid WK's with electric gremlins. New or even reprogrammed modules are unavailable from Jeep. And 15 yr old modules understandably have issues. I have been searching for software that is affordable and will reprogram salvage modules. AppCar and AlfaOBD do not. Have looked extensively and found nothing other than very expensive business level scan tools that may or may not reprogram FCM/IPM/SCM and maybe PCM.
Gone thru so many websites and detailed threads my head is spinning.

If anyone knows of an affordable DIY option-----Please let me know!
Thanks!
Bob

UPDATE:
Drove vehicle without any DTC codes for approx 10 miles. Repeated. Put all the interior plastics back in place and thinking AOK!!!!!

Bottom Line: Swapped salvage FCM IPM and SCM. (body computer/fuse box/clockspring) No programming. All DTC's disappeared. Everything seems to work. Network feels stable after about a dozen recycles/starts.

Lessons Learned:

1. Computer Modules are not like swapping parts.
2. Replacement Modules should be given 17 seconds on. Then ignition off. Then ignition on for several minutes to allow network resets.
3. These older WK Jeeps have fewer modules of older types. (Only 27 modules and designs are 23+ years old. They are inherently unstable compared to newer.)
4. AppCar DIAG FCA became my go-to software. Spent a lot of time looking at the settings and data from each module. Clearing codes. Retesting to see if codes return. Prime example was centering the steering angle reading which is related to install of clockspring SCM. Cleared and reset most of the major modules without problem.

Cleaning grounds, checking wiring harnesses, replacing battery were all important. Swapping modules and installing them gently cleared things up.

Just wanted to update status for all those who offered to help and others who experience similar problems.

Bob P