Allpar Forums banner

1 - 20 of 42 Posts

·
Registered
Joined
·
25 Posts
Discussion Starter · #1 ·
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...all I get is "- - - - - - -" and then "- -done- -" and it never displays any codes.

I'm very familiar with turbo Dodge cars of the 80s and 90s (the 2.2 and 2.5) but this is only my second 2.4 PT Cruiser. I have also a 2005 PT 4 door that is not giving me any trouble but I went through the head gasket, mounts, and timing belt routine on it when I got it.

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.
 

·
Registered
Joined
·
4,833 Posts
. . . . 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...all I get is "- - - - - - -" and then "- -done- -" and it never displays any codes. . . . ..
Check all fuses in the TIPM (totally integrated power module) box located near and under the brake master cylinder reservoir. Fuse #33 provides power to the OBD II port and must be continuous and providing power to the port for a scan tool to function properly.

Data Link Connector Power Fuse.gif
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #3 ·
Ok and thanks, I will check it first thing in the morning. The Foxwell and Autell scanners do power up when plugged in BTW, but I will check that fuse first thing.
 

·
Registered
Joined
·
8,339 Posts
Keep in mind that the 06 PT was the first year for the TIPM, too. Not all of the bugs were worked out. Just for the heck of it though, remove your air box and check your ground connections on the inside of the driver side fender. This is a known problem area on the PT's. And don't just look at them. Take them off and clean them and reconnect them. You just never know when a bad ground may be the culprit.
 

·
Super Moderator
Joined
·
21,702 Posts
A 2005 PT is the old PCI bus. A 2006 is the CAN bus and a TIPM. Are your OBDII scanners able to read CAN bus vehicles?
What model numbers? Have you Googled this issue?
I have heard of communication issues with generic scan tools. The factory Powertrain Diagnostic Procedures service manual has a section for troubleshooting 'No Communication' problems.
Has the TCM been replaced? Is it pulling down the bus and causing the 'No Comm' issue?
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #6 ·
ImperialCrown: My scanner is a Foxwell NT301, it can read CAN interface, in fact when it is cycling through its data gathering/read modes I see a reference or two to "CAN Interface". The AutoZone Autool was also able to read CAN interface in fact, the guy waiting in front of me to get his codes read, got his codes in about a minute. The point to keep in mind here I think is not so much if the brand new readers can read CAN but the fact that the car itself will not display codes. I dont think its a case of having a CEL (check engine light) and no codes...but I guess it's possible.

AFAIK, the ECM in this car has not been replaced, but I don't have any way to confirm that really. I bought the car 2nd hand, it was bought at a car auction by the (dealer) man that I bought it from, he put nothing into the car as far as repairs go.

I Googled the issue many many different ways before even posting, it's SOP for me and though I came up with nothing more than 'how to pull codes' after the 2nd or 3rd page of SEPRs the links became more and more less relevant.

There does not seem to be a separate "Powertrain Diagnostic Procedures" book for the 2006+ model years. I dont yet have a set of hard cover factory service manuals but I suspect a used set is not far off in my future. They are available for around $250. I wonder if the Powertrain Diagnostic Procedures has been rolled into one of the 4 volume sets. Do you know, any one Bueler, Bueler?
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #7 ·
CHUZZ: Thanks for the ground tip! I will also check those grounds today along with the TIPM fuse(s) suggested by AllanC. No problem removing the airbox...the car doesn't have one. The PO installed a rather silly looking fresh air system with a chrome tube and K&N filter. That thing is coming off there and I'll find a factory housing and hose for it right away. I don't really want to hear the turbo spooling down every time I let off the gas.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #8 ·
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 dab 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?
 

·
Super Moderator
Joined
·
32,330 Posts
Since the cover was off the fuse box, and debris inside, I would unplug and plug in every fuse and relay to eliminate the possibility of corrosion between the contacts.
 

·
Registered
Joined
·
4,833 Posts
You have checked the obvious items such as fuses, etc and found no problems. So I am thinking there is a problem with one or more modules on the CAN network that is causing it to fail. Or the CAN network wiring is shorted to ground or open. You are going to need a factory service manual and the chapter 8 reference to wiring and BUS communications. It will show the CAN network with each module connected to the network and the connector pins at each module.

It appears that the TIPM is the master controller for the network. You will have to methodically disconnect each network module and check wiring for opens and short to ground. If a module has failed internally and stopping network function, disconnecting it should allow the network to come back to life. This can be a tedious process.
 

·
Super Moderator
Joined
·
37,862 Posts
The other problem is any module swapped in is going to need the VIN programmed into it or there will be a VIN mismatch error. That might be a step up from nothing though.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #12 ·
"Since the cover was off the fuse box, and debris inside, I would unplug and plug in every fuse and relay to eliminate the possibility of corrosion between the contacts."

I did exactly that, pulled and checked them all. My shop manuals should be here in a few days, I will study up on the CAN network and start tracing and checking circuits with my VOM. I have no idea what the past service history on the car is so who knows what might or might not have been swapped in or out at this point. I think it safe to say that at the least the ECM has been swapped. I am researching a service that can check it, and reprogram it if necessary or replace it if Humpty is too broke to put back together again.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #13 ·
Engine code = S = 2.4L 4 Cyl. (EDV) (PT27) GT Convertible HO engine code, DGL 4 speed automatic transmission

Trying to determine what engine controller I MIGHT need, just to be ready if it comes down to that I'd like to start hunting down options and want to know the correct part number. 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. I do understand that the module will have to be programmed for the car and that the VIN and mileage will be needed.


 

Attachments

·
Super Moderator
Joined
·
21,702 Posts
The dealership parts counter can probably enter the last 8 of your VIN and pull up what PCM the car came with.
It looks like the 5033439AB is for DDD (stick-shift) cars.
Mopar got out of reman PCMs due to the fact that many became a revolving door in the service department and was hurting customer satisfaction scores. Too many times an intermittent issue with a PCM would pass through the parts pipeline again and again.
Mopar now sells new or 'blank' PCMs that get filled with the correct software and initialized at the service dept.
The PCM and TCM functions are in the same controller (NGC) housing.
 

·
Super Moderator
Joined
·
37,862 Posts
The transmission is the difference. DGL is the auto and goes with 05033441AB. DDD and DD5 are the manual transmissions and go with 5033439AB. Your red highlights drop from one part number to the next.
There is also a good change there is a revision for the software that may have a higher revision at the end than AB.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #16 ·
valiant67....Duh, I feel like a blockhead and you are right, the red square I did drop into a different part number. Duh! Great catch, now I know what to look for.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #17 ·
Does it mean anything that wold 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.
 

·
Registered
Joined
·
4,833 Posts
. . . Does it mean anything that wold 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? . . . .
All segments in the PRNDL illuminated indicate that the logic module in the instrument cluster does not know which position the transmission selector is located. It is not getting a logical signal from the TRS (transmission range sensor).

There are 4 binary sense switches in the TRS which signal by being either OPEN or CLOSED and provide the necessary information for the instrument cluster to illuminate the correct symbol in the PRNDL display. See attached diagrams. The diagrams are for a 2003 PT Cruiser so the wiring colors could be slightly different but the pin locations are correct.

Transmission Range Sensor Wiring.gif Transmission Range Sensor Pinout.gif


Check and make sure there is 12 volt power at wiring cavity #1 with ignition key switch in the RUN position. To check the sense switches, remove the TRS electrical connector at the transmission. Use a multi-meter and check for continuity to ground on pins #7, #8, #9, #10 against the transmission case. The diagram shows the positions of the selector lever when the switch is closed. For example sense switch T41 is only closed in PARK, NEUTRAL.
 

·
Super Moderator
Joined
·
21,702 Posts
If the CAN bus is down, that would prevent you from reading PCM/TCM codes AND light the PRNDL (as communication between the TCM and instrument cluster (CCN module) isn't happening.
I would begin with diagnosis of the CAN bus system to find out if it is operating. I would hold off replacing any modules yet.
 

·
Registered
Joined
·
25 Posts
Discussion Starter · #20 ·
AllanC/ImperialCrown, thank you both for sticking with me on this, I just got my factory set of shop manual and started my research on testing/diagnostics both CAN and transmission. Of course many of the procedures require the special dealer tools but having the wiring diagrams at the very least I can verify grounds and power and many other things. Obviously getting the CAN interface working will go a long way in solving all the issues and help in diagnostics VS just throwing parts at it. Both of you gave me something to work through, I'll do these things and report back out as soon as I can. Looks like 3 days of solid rain here in Atlanta so it might be Thursday before I can get a hood over my head and a wrench under me. THANKS again to all.
 
1 - 20 of 42 Posts
Top