Intermittent starting problem, have to pump brakes?

GordnadoCRD · **Posted:** Wed Apr 26, 2017 7:57 pm

Does your security light come on or flash when this happens?

allenj · **Posted:** Thu Apr 27, 2017 9:41 am

I hadn't specifically noticed, the dash lights all come on as they usually do for a normal start which includes the security light, no blinking that I remember.
I'll check it out next time it happens.

allenj · **Posted:** Fri May 19, 2017 12:55 pm

It's been a while, here's a quick update.

I took the Jeep to my local independent diesel mechanic, intending to have the starter replaced. They tested the starter and said it was fine, but diagnosed a problem in the WiFi starting circuit, the TIPM or the ECM. They confirmed that all the steps I've done so far were proper troubleshooting (replacing ignition switch, interconnect, and starter relay), but at this point the vehicle has to go to the dealership for further work since the problem is in the computers. And they didn't even charge me for the diagnosis (kudos to Global Performance in Raleigh, NC).

I'm taking it to the dealer next week. I do find it somewhat suspicious that this problem started happening within a few months after getting the TSB 08-043-05 flash to recalibrate the temperature gauge. I don't see how it could be related, but I'll definitely mention it to them.

dkenny · **Posted:** Sun May 21, 2017 9:17 pm

I wish I had seen this post a few days ago..

wife jeep had same problem...

I tried to trace down the wiring..the book doesn't make it easy.

finally concluded that jumering 30-87 on the relay.. i think WWDiesel posted the diagram..that would
have made it much easier.. I jumpered those...the start didn't spin..

took a bar to the starter and solenoid..tried again..to spun...

put the column back together..tried the key..it worked...

turn off..tried again..nothing...
a new starter is on the way..I couldn't find a place in Raleigh that had one on the shelf..
ordered Rock Auto..new..no core..

also I'm not far from the OP..we could have collaborated... oh well.

-dkenny
its the dark blue CRD you might see in Apex..

allenj · **Posted:** Tue May 30, 2017 9:15 am

Local dealership thinks it's a problem with the PCM, and estimated $1900 to replace ($1100 just for the part).
I'm not spending that much on a Jeep this old that I don't plan to keep forever that at least mostly works.

Anybody have any recommendations for a reputable place to get a used/rebuilt PCM for my CRD?
I've seen salvage ones online for $150 but wonder if it would require VIN specific reprogramming, and at least one of the most common replacement computer vendors in search results has horrible reviews.

flash7210 · **Posted:** Tue May 30, 2017 9:20 am

Any replacement ECM, whether new, used, or reman, will require your specific VIN to be programmed into it.
There is currently a used ECM available on ebay for $199.

Given the intermittent nature of the fault, I doubt its the ECM. But I'm not the one actually there with tools doing the diagnostic work.

allenj · **Posted:** Tue May 30, 2017 9:37 am

So if I buy a used PCM/ECU (salvage / eBay), how would I get the VIN programmed?

The consensus of the senior diesel mechanic (27 yrs experience) and shop foreman at the dealership was to replace PCM first. They said when the problem is occurring, their diagnostic tools can't communicate with the computer at all, it's like the vehicle isn't even there, and PCM replacement is the 'first step'. But that being said, like any intermittent electrical issue, there's no guarantee that will fix the problem. Yet another reason I'm reluctant to drop that much money on it.

Thanks.

flash7210 · **Posted:** Tue May 30, 2017 10:24 am

The dealer should have the ability to program the VIN into the ECU.

The mashup of different electrical parts and modules used in the CRD often creates communication issues. That said, the Chrysler StarScan tool is the gold standard and should communicate without problem.
Do you have a code scanner that works?
If so, you could disconnect your MAF or MAP sensor, key on/off a couple times, and scan for codes. If you get some codes then you know the ECU is ok.

Maybe the problem is actually in the BCM (or FCM or gateway module or whatever its supposed to be called)?
The BCM is kinda like the central hub for communication with all the various modules.
A bad BCM can cause all kinds of weird electrical problems. (so would a bad ground)
On a 2005 CRD, the BCM is on the drivers side frame rail, almost directly below the battery, kinda next to the AC compressor.

allenj · **Posted:** Tue May 30, 2017 11:31 am

OK, thanks.

I do have a very basic code reader for the Liberty, which I've been using recently to check and clear the P0101 signal that's been occurring intermittently. I've cleaned the MAF and replaced the MAP but it's still happening, I haven't replaced the MAF yet. Possibly it's even related to this issue, it's been occurring during the same time frame, but it didn't seem likely?

So I can try your troubleshooting scenario, and/or just try a salvage ECU and/or FCM (which I also see on eBay for $189).
Hmm...

flash7210 · **Posted:** Tue May 30, 2017 12:36 pm

If you are able to pull codes then its most likely that the ECU is good.
P0101 is for the MAF and is very common for CRD owners. Most just leave the MAF unplugged and live with the light being on. The MAF does not effect engine performance and is not related to engine starting.

allenj · **Posted:** Tue May 30, 2017 12:55 pm

I haven't tried to pull codes at the time the starting problem is occurring. Assuming the description from the Jeep mechanics is correct, this would not be possible. When the starting problem is not occurring, ie when the vehicle is cold or after it has already started, then all works fine, including communication with the computer.

About the MAF, I agree, and if it were up to me I would leave it disconnected. Unfortunately this is my wife's car, and she doesn't like seeing the CEL.

allenj · **Posted:** Tue Jun 13, 2017 5:48 pm

Time for an update and another question!

So I took our Libby to the dealership, they diagnosed the problem as a faulty PCM, since they said when the problem is happening they can't talk to it at all, it's like the car doesn't even exist as far as their computers are concerned. Quoted price for a new PCM installed is $1880 :shock:

And they can't even guarantee that it will fix the problem, it's just the first recommended step.

I wasn't willing to pay that much on a vehicle that I'm essentially fixing in order to sell at this point, so I experimented with purchasing a salvage PCM off eBay, from the same year and model Jeep. When I plugged in the replacement PCM, the Jeep starts promptly, then dies after 5 seconds, presumably due to security code mismatch.
I took it to the Jeep dealership hoping to get it recoded to my VIN, which they said they would do for $130 (1 hour shop rate), with me doing the labor to swap the PCMs to get it ready. But when I got the salvage PCM in the vehicle, their computer refused to recognize the VIN on it and talk to it, so they couldn't update it! The mechanic said it's a security thing on the 'newer' wireless units, so I can't even flash it, apparently it must be either an empty PCM or one pre-coded with the VIN.

Here's the question. I know there are many shops online that claim to sell pre-coded, plug and play PCMs, or even support PCM repair by mail.
I figure this is probably the next thing to try. Does anyone have any recommendations for a reputable shop that handles the CRD PCMs?

Thanks.

WWDiesel · **Posted:** Tue Jun 13, 2017 8:59 pm

Contact Green Diesel Engineering, they may be able to help you or at least guide you to a better solution... :wink:

Green Diesel Engineering
(248) 977-9531
support@greendieselengineering.com

allenj · **Posted:** Fri Jun 23, 2017 1:50 pm

Thanks for the GDE reference! They were able to flash my VIN into the salvage PCM/ECM with a total turnaround time of less than a week.
I plugged in the PCM/ECM and the Jeep started right up! I initially had a bunch of codes, but after clearing them with the engine running I guess i convinced it that it's the 'new normal'. I've driven it a couple of times since, including a hot start scenario, and it starts right up with no hesitation and no more codes!

Intermittent starting problem, have to pump brakes?

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