Not sure but I hope this posted.

 

hold on as we get you some info..

First one on the regulars here is our go to for PCM issues @Waterluvr - will hopefully get back to you soon. DO not get another PCM without speaking with him.

RIght now it Starts and runs.
You do not see a security key light?
Is the CEL ( Check Engine Light) on and P1686 is gone?
Just no gauges - speedo and tach ok?

 

Cheer up Mr Grumpy, I think you solved your problem.
Crud (oxide) builds up on the metals contacts in the plugs and the sockets between this and that.
In your case, you scrapped the crud off when you unplugged your black box (module).
And scrapped some more off when you plugged it back in.

Unplugging and plugging in a few times is what I do when electronics pay up.

I usually smear a bit of grease round the plug & contacts just before the last plug in.

You can even buy cans of "Contact Cleaner." which should show you how common the crud problem is.

Some here, I don't particularly recommend it though: - https://www.ebay.com/sch/i.html?_fr...?_from=R40&_trksid=p2380057.m570.l1311&_nkw=electrical+contact+cleaner&_sacat=0

 

x

 

Yes, the security key light is on and will always be on as I've removed the SKIM Module from bottom side of steering column and the ECM has had the SKIM program removed/deleted. The P1686 code is now gone as the ECM is no longer looking to hear from the SIM Module. The check engine light has always been on since my wife got the Jeep 3 years ago. No codes. All gauges don't work in the cluster, including speedo and tach.

 

The check engine light has always been on since my wife got the Jeep 3 years ago. No codes.

You are using a SCANNER to look at codes?
The key on off trick may NOT show all codes.

If you do not have a scanner take advantage of the FREE scans many auto part stores do, its FAST and FREE.

 

UNtil waterluvr can help, some ideas -
That SKIM delete IDK, I remember something not so simple easy as programing it out.


what is voltage at cavity 2 of DLC?
what is voltage cavity 16 DLC?

 

I can't help here with a skim modified pcm, they are unsafe as certain key safety features of the asd relay become disabled and they always have issues like failed bus data to the dash sooner or later.

Put a stock pcm back in, hook up the skim module and do it right to get a dependable daily driver back on the road.

 

do you have the original PCM?

My colleague is the go to person for WJ PCM issues, he mentioned issues with removing the SKIM feature, I do not know the details.

I would suggest you try a SCAN for any and all codes.
Maybe confirm the ICM is on PCI bus. DLC cavity #2 to ICM cavity #10. would be a DIYer check BUT a pro scanner will make easy.

 

jtec, Thanks for helping. Bear with me a little please. Checking cavity 2 and cavity 16 results in 0, nothing.

ICM, where would that be, so I can check DLC Cavity 2 with ICM cavity 10? My scanner, just ODB II shows no codes. I drove to O'Reilly's and they checked it out with their scanner and didn't get anything recognizable. Some kind of number 15 only. Would you believe battery died on the way and I had to get a new one. Please keep in mind I Live in the northwoods of Wisconsin and No Dealers or Mechanics will work on this 2001. They all say no guarantees and I still would owe them for their time. In fact, it was one of the Dealership Service and Parts Department that suggested the best route to go was have the SKIM Program deleted.

Frustrated and Grumpy Old Man.

Thanks again jtec. Hopefully we can figure this out.

 

The ICM is your cluster, there are some other names but the cluster will be enough for now.

All the instrument inputs travel from the PCM to the various modules on a bus.
The concern here is confirming the PCM to the ICM over the bus.

Start with under dash fuse box, check fuses #17 and #22, check them with a DVOM , do they have 12v both sides?

Next check the continuity form DLC #2 to ICM connector cavity #10.

this will help with how to remove cluster
https://www.wjjeeps.com/gauges.htm#REMOVAL

 

fuse box diagram - might help you

 

Waterluvr, Thank You for replying. I agree 100% with doing it the Right way but on occasion you just can't. That is my situation. As I live in the Northwoods of Wisconsin, Dealerships are a long distance away and local mechanics don't have the expertise nor the modern equipment to troubleshoot, plus I would have to get the vehicle towed there. When I called and spoke to all these folks the reply was always the same, Sorry but we can't help you because we don't have the ability to program the ECM for a vehicle that old, can't get a new SKIM module and even if we try we can't guarantee we could fix the problem and you would still be responsible for their service/labor/parts, over $1000 just on a Maybe. It was one of the dealers that suggested to do a SKIM by-pass/delete. That is why I had to go that route as all I had at that point was a dead vehicle. THE JEEP Guy on youtube had a step by step video on how to remove the ECM, send it off to All Computer Resources to have the SKIM removed and re-install. After some research and calls and with the P1686 code this was the only suggestion folks up here had. The Jeep now runs with the exception of no gauges. Again, maybe not the best choice in hind sight but seemed like the only choice at the time. Once again Thank You for replying.

Grumpy Old Man, Wayne

 

Wayne let me try and make this as easy as possible for you and if you have some time please search this forum for my username and pcm replacement as we have done this over and over and over again in past threads.

When your pcm is shot you go to the junkyard and pull a matching part number from a same model year and drivetrain wreck. The last 2 digits in the part number can be anything from (AE-AJ).

From there we start an email chain with your vin number and some more info, you mail that pcm to me and I do a dealership level OEM reflash on it and when it comes back it's plug and play ready for you.

If you can't find a pcm locally for cheap I can find one in a yard that pulls and inventories them for you to buy. The idea here is you need to source a pcm that hasn't been repaired or tampered with they are all junk.

You mail it to me, I mail it back and your driving again for very little cost and no more hassles. A fast and very effective troubleshooting tip here, plug that replacement pcm in before sending it to me and if the dash works and you get a crank/start/shutdown 2 seconds later your troubleshooting is all over and the pcm is the cause of it all.

Send me a pm with an email I'll be glad to help you get this fixed the right way.

 

Okay jtec. Lots of weather here today so my time outside quite limited. Fuse #17 has 12V both sides with vehicle off and while running. Fuse # 22 has 12V both sides only when vehicle running. As far as continuity between DLC #2 and ICM # 10 very difficult getting the probe in far enough on ICM #10 but Best I can see No continuity. Also, the DLC has different pins than the diagram you sent. Mine has pins at:1, 2, 3, 4, 5, 7, 9,11 and 16. I have 12V at #1, no V at #2, no V at #16 and about 1.5V at #7. Hope this helps.

 

be sure the DLC is not flipped up side down on vehicle - it is longer on the 1-8 pin side than the 9-16.
With NO 12v at 16 - try 16 with key on -

I will recheck manuals and post again.

TIP; You can umplug ICM. stick straight pin thru wire at cavity 10 (VT/RD) and clip DVOM onto straight pin TO ASSIST CHECKING continuity, manual suggests checking ohms but I never see resistance only open or continuity has been my experience.

 

DLC 16 gets 12v from fuse 17 in JB (in cab) fuse box....
that would be very very interesting if your correct no 12v DLC 16.
Concentrate on that 12v at DLC 16.


DLC 2 to ICM 10 is to check PCI buss continuity.

 

Okay, better weather and better feedback. I unbolted the DLC plug and was able to access numbers. Yes, # 16 has 12V whether key in off, on or with vehicle running. Pin # 2 has about 0.5V again whether the key is off, on or with the vehicle running. Pin # 6 has 5.0V in on or with vehicle running. Also, there is continuity, 0 resistance between DLC # 2 and ICM # 10. Other pins have no voltage no matter off, on or vehicle running. My DLC has pins at:2, 4, 5, 6, 7, 9, 14 and 16.

 

OK you have exhausted the wiring and PCI continently checks, what the trouble tree calls "preliminary"
a SWAG - Keep an eye on that DLC #16 issue, that being no voltage at your test would explain the gauges AND the scanner not connecting. That's why I called it interesting. gauges and DLC#16 same circuit.
You will need to address the code (P1686)* that started all this, Then work with waterluvr on getting a PCM, SKIM and keys. Often with this code we see a broken wire at the SKIM. Another quick check if your ready.

TMI: Why the SKIM bypass creates other problems IDK - that is the PCM technicians world.

*P1686-NO SKIM BUS MESSAGE RECEIVED

 

DLC #16 is not an issue once I was able to identify the proper cavity numbers. #16 is 12V all the time.

After new battery was installed they rechecked for codes and none were found.

Any more checks or suggestions? I'm not familiar with some of the abbreviations.

I'm retired and on a strict budget so spending more money becomes questionable. I drove the Jeep on a small 100 mile trip yesterday and it ran fine except for no dash guages.

Thanks for all your help to date.

 

the issue started with the P1686* code, simply put the SKIM is not seen on bus.
THere are 4 wires to SKIM we can check. see attachment.

You now know the PCI bus is at teminal 2 of the DLC. see post #8 and post #17.

Attached is the SKIM module connector, note two 12v sources cavity 1 and 3, a ground
at cavity 2, and then cavity 5 the bus.

Confirm check the 12volt sources, check ground, then check continunity cavity 5 to the DLC cavity 2.


P1686-NO SKIM BUS MESSAGE RECEIVED

 

A noticed I asked if there was continunity DLC #2 to the ICM (gauge connector) cavity 10 see post 21 above. yes or no?

 

yes yes I know you removed the SKIM BUT to get waterluver to help (PCM,SKIM, KEYS) your system has to be operating CORRECTLY.

 

Okay, tests complete. DLC #2 to ICM #10 = O Resistance, Continuity.

DLC #2 to Skim Connector #5 = Continuity BUT Reisstance Pulses back and forth between 150 Ohms to 225 Ohms.

Skim Connector #1 = 12V.

Skim Connector #3 = 12V.

Skim Connector #2 Ground = YES to Chassis.

Sorry for the delay but I had a little AFIB Episode.

Thanks You Again, Wayne.

 

I few more voltage checks I made today, before the rains came, hopefully they can help you with the diagnosis. DLC #2 has about 0.8 Volts when key is off and the meter needle swings back and forth about 0.1 Volts constantly. With the Jeep running it is about 0.5 Volts with the same swing.

At DLC #6 I have 0 Volts with the key off and 4.5 Volts with the jeep running.

Then just because I was curious I ran voltage checks with the jeep running from DLC # 16 to #2 got 12 volts, to #4 got 12 volts, to #5 got 12 volts, to #6 got 9.5 volts and to #7 got 11 volts.

With the Jeep running I also checked headlight switch and dash light dimmer, all window controls, tilt steering wheel and the gauges remained dead as I operated all those.

Thanks, Grumpy Old Man, Wayne.

 

jtec, haven't heard from you in a while I hope all is well.

What is next? I need to get this resolved so my wife can drive the Jeep.

I greatly appreciate all your help to date.

Thank You, Grumpy Old Man, Wayne.

 

"DLC #2 to Skim Connector #5 = Continuity BUT Reisstance Pulses back and forth between 150 Ohms to 225 Ohms."

That is interesting, the key is OFF and removed from switch?
We are using DLC #2* because it is easier than PCM terminal C3 30.
read the trouble tree above step 3 measures resistance.
The diagrams shows where the readings are measured, C3 is which PCM connector, 30 is cavity in connector, check wire to wire at PCM and SKIM.

Again with a scanner we were done with this and our coffee in @5minutes.

* access to DJP (Diagnostic Junction Port) see diagram.