[ILIKESHELBYS]

Hello All,

Just bought a 2006 PT Cruiser and I knew the check engine light was on. Was told the car needed a transmission control module (TCM I guess its called). So the dealer dropped it off today and when I attach my brand new Foxwell scanner to the ODBII connector, after a minute or two I get a "No Communication" message. Took it to AutoZone to get them to read codes, same problem "No Communication" message. Tried the traditional key dance...on off on off on and all I get is "- - - - - - -" and then "- -done- -" and it never displays any codes.

I would appreciate any insight as to what might be common causes for not being able to pull codes.

BTW, the car starts and runs fine except that it is stuck in limp in mode/2nd gear.

Oh yeah and the ABS light is also on, I just need initially to be able to pull codes so I know where to go from here.

 

[NAJ]

There is a communication issue with the CAN Bus System.
You probably have a "U" code stored (Lost Communication Code) and are just not able to access it with your scanner.
You will need the appropriate service info (either an FSM or Alldata) to find the correct diagnostics for this issue.

Start With Basics...
1)Be sure all fuses are good (power in and power out, in the Fuse Block and Underhood PDC)
2)Verify all Engine/Body Grounds are connected and all Controller Grounds have Continuity to ground.

Unfortunately there are no shortcuts for diagnosing a CAN Bus System communication issue.

https://repairpal.com/obd-ii-code-u0100-lost-communication-with-ecm-pcm-a

 

[John83Rampage]

Seems I had a similar problem with my '04 Sebring hooking up a scanner. After plugging it in a few times it started working. Must have just been dirty/dusty contacts in the connector. Hope your issue is as easy to resolve!

 

[ILIKESHELBYS]

NAJ, thanks for the guidance, looks like I am up to bat for the next session of "CAN school". I have already learned quite a bit just watching videos, including the two you provided links to above...so thank you for those resources. In another forum (Allpar) it was suggested that I be sure to check fuse #33 in the TIPM, it provides power to the diagnostic connector as well as checking the grounds under the airbox on the drivers inner fender. Apparently this ground bundle is a common problem and should be carefully inspected. So, I'm going to check the grounds there and look for others, and check all fuses.

BTW, just purchased a set of factory shop manuals, a 4 volume set used, but good condition. $125 shipped.

 

[NAJ]

Seems I had a similar problem with my '04 Sebring hooking up a scanner. After plugging it in a few times it started working. Must have just been dirty/dusty contacts in the connector. Hope your issue is as easy to resolve!

Chrysler did not start using a CAN Bus System until 2006 (Except for the 2005 Durango which was the first Can Bus System), much more complicated system than the standard CCD Bus System.
That is when we had to switch from using the DRB3 scanner to the New Star Scan system.
In 2006 the DRB3 scanner became obsolete and relegated to only 1996-2005 vehicles.

 

[ILIKESHELBYS]

Chrysler did not start using a CAN Bus System until 2006 (Except for the 2005 Durango which was the first Can Bus System), much more complicated system than the standard CCD Bus System.
That is when we had to switch from using the DRB3 scanner to the New Star Scan system.
In 2006 the DRB3 scanner became obsolete and relegated to only 1996-2005 vehicles.

Sure glad I didnt decide to buy that $1500 used DRB3 tool last night!

 

[NAJ]

BTW, just purchased a set of factory shop manuals, a 4 volume set used, but good condition. $125 shipped.

Paper manuals are nice, nice to hold in your hand and flip through the pages, however paper manuals are being phased out and will soon be obsolete.
In my last days at Chrysler they were slowly eliminating paper manuals and requiring all dealerships to improve/install dedicated Wi-Fi in the shops for all Shop Computers and Scan Tools.
This also allowed Chrysler to make immediate corrections to service info and allow the techs access to all TSB's/Recalls and Service Info with just a VIN.

Also, All of the info in those 4 manuals you purchased is available with a DIY Alldata subscription for 1/5 the price.

When working on a car at home my Son used to bring his laptop out to the garage so he had all of the service info available to him right there from Alldata.
We purchased Alldata for all of the family vehicles, had subscriptions for 6 cars at one point.

https://www.alldatadiy.com/

 

[NAJ]

Sure glad I didn't decide to buy that $1500 used DRB3 tool last night!

Yea, would not have worked on your 06.

 

[NAJ]

https://www.dcctools.com/en/ss_info/

 

[ILIKESHELBYS]

I checked the grounds under the airbox and on the drivers inner fender, they actually looked very clean and un-molested but I took them loose cleaned with a wire brush, even put some solder over the end of one of the connectors to make double sure the copper wires were making contact with the eyelet. The bolts were tight, no corrosion present, the wires haven't been monkeyed with it seems. I can tell that there was someone here before me because there is a dap of blue paint on most the items I am checking having to do with the diagnostic, the ground eyelet had blue mark on it, the bolt heads for the ECM bracket had the same blue paint on them, etc.

I removed the ECM, checked all the pins, they looked pristine, checked the connectors, they all looked good with no pushed back connectors, all very clean. Check every fuse in the fuse box, all clean and not blown. I do know that the fuse box cover is missing, I suspect that it was left off in favor of the K&N Typhoon fresh air system that is coming off the car as soon as I can find a turbo air box. There was some debris in the top of the fuse box, which was cleaned out. I have not yet, lifted the box up to see if there is maybe some water damage to the underside due to being left topless...but I plan to.

Pulled the ECM out to get the number off it, I would say that it has been replaced. It has absolutely no numbers or factory part number labels on it at all. Just a re-builders silver warranty sticker over the seam indicating void if seal broken...but all other labels have been removed.

I am going to need that part number. Can anyone chime in on the correct partnumber for a 2006 turbo PT Cruiser convertible with the security/chip key system?

 

[ILIKESHELBYS]

Engine code = S = 2.4L 4 Cyl. (EDV) (PT27) GT Convertible HO engine code, DGL 4 speed automatic transmission

Can anyone tell me what the difference is between these two engine control units?

05033441AB
05033439AB

They both seem to fit the 2006 HO turbo engine code S cars with the 4 speed DGL transmission. I THINK I read somewhere that one might be for cars w/o the security/immobilizer/chip key setup and the other for the no chip key setup...but I can not find that reference any longer.

 

[NAJ]

Just an FYI...
External PCM numbers may be a mute point if there was ever a TSB requiring the unit to be flashed, it would then require a new part # that would be on a label placed under the hood.

You may want to try contacting the dealer to see if those are the latest part #'s available.

Also. if you had access to Alldata you would be able to check for TSB's that required a flash.

The first part # you listed came back as "not found".
Here is info for the second part number which has been superseded.
Type the number into the search box and you can see all of the vehicles it fits.

http://www.wholesalemopar.com/parts_catalog.html

It is also used on Non-Turbo cars.

Old Part Number 05033439AB
New Part Number RL033439AD
Part Name MODULE POWERTRAIN CO
MSRP $607.00
Core $125.00
Online Price $422.24

2007 - Chrysler - PT Cruiser Base - EDZ - L4 - 2.4L - GAS
ELECTRICAL / POWERTRAIN CONTROL / POWERTRAIN CONTROL / CONTROL MODULE
RL033439AD - CONTROL MODULE POWERTRAIN CONTROL MODULE; PT Cruiser; Ultra Low Emission; w/High Output; Manual Trans

 

[ILIKESHELBYS]

Thanks for the insight NAJ.

I made a mistake in my diagram. The correct ECM is going to have originally been 05033441(AB), it's had several updates and it seems the last update may have been AH

 

[NAJ]

If the PCM is a Chrysler unit and it has been "Flashed" there will be a sticker on the ECM and a sticker on the hood or radiator support showing the new part # and the TSB #.

 

[ILIKESHELBYS]

If the PCM is a Chrysler unit and it has been "Flashed" there will be a sticker on the ECM and a sticker on the hood or radiator support showing the new part # and the TSB #.

:smile2:

 

[ILIKESHELBYS]

Does it mean anything that would help me continue to diagnose this problem to know that the "PRNDL" has all the segments lit? I noticed driving the car tonight that "PRND" are all lit and moving the gear selector doesn't make any difference. Is this maybe common for cars stuck in limp-in mode/2nd gear?

I was told when I bought the car that it needed a TCM (transmission control module) and I know in 2006 it is part of the ECM module but since I can't currently (*yet) pull codes I don't have a convenient way to determine that it needs a computer or it's something else.

 

[NAJ]

Does it mean anything that would help me continue to diagnose this problem to know that the "PRNDL" has all the segments lit? I noticed driving the car tonight that "PRND" are all lit and moving the gear selector doesn't make any difference. Is this maybe common for cars stuck in limp-in mode/2nd gear?

Unfortunately I have no idea.
Working at a dealership I had access to all service info, tsb's and scanners.
I have no info available to me now.

 

[charger R/T]

Tried the traditional key dance...on off on off on and all I get is "- - - - - - -" and then "- -done- -" and it never displays any codes.

The key dance did work. That is exactly what the engine computer shows when it isn't storing a code.

I'm not familiar with your scan tool does it scan just engine computers or does it scan all modules?

If the trans is in limp mode I would unplug the tcm and try to scan the system a down fall of the can system is if a module fails it can talk trash on the system and you can't talk to anything. We recently had a crown vic not talking the instrument cluster was the issue. we unplugged it and the the ecm and abs started talking again,

If that doesn't help breakout the books and start ohming the buss network starting at the obd2 plug. make sure the obd2 plugs power and grounds work.

maybe we can learn the pt's together I just pulled the pistons out of an 05 PT turbo we picked up for scrap value. Last owner pulled the head when the timing belt broke and he thought it had bent valves. So now cylinders need honed water in holes started to rust.
Tim

 

[Chuguley]

check your cig lighter fuse same one powers OBD

 

[ILIKESHELBYS]

check your cig lighter fuse same one powers OBD

I did check all the fuses first, they are all good. I also physically removed each of them and inspected. I have also been pulling connectors, looking for pushed back pins, corrosion, chafed wires, repair splices, etc. So far everything looks clean and original. Thanks for the suggestion.

Check