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2006 PT Cruiser GT, cant read OBDII codes

37K views 44 replies 10 participants last post by  junktardis 
#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.
 
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#2 ·
. . . . 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.

Text Line Diagram Font Parallel
 
#4 ·
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.
 
#5 ·
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?
 
#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?
 
#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.
 
#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?
 
#9 ·
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.
 
#10 ·
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.
 
#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.
 
#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.


 

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#14 ·
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.
 
#15 ·
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.
 
#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.
 
#18 ·
. . . 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.

Text Diagram Line Circuit component Parallel
Text Font Line Parallel Diagram



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.
 
#19 ·
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.
 
#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.
 
#22 ·
Got back on the 2006 PT Cruiser today and I would have to say "What a surprise!"

Car has not been started in about 10 days so battery was not quite strong enough to start the car, put it on the charger for a couple hours and it cranked right up. CEL and ABS lights still on of course, gave it a chance to warm up and then took it for a short drive just to keep all the systems turning after not being driven often. As you might recall, this car I could not get to communicate with my scanner (CAN bus down/no communication)and was stuck in limp in mode, transmission in 2nd gear all the time.

Well I drove off from the house and the transmission was shifting! Drove around the block and it was shifting great, all 4 gears, the PRNDL was properly displaying the gear selected, car drove very nice. Drove it for about 20 minutes this way, never skipped a beat, no driveability complaints. Pulled back into the drive and grabbed the scanner BEFORE turning the car off. Plugged it in with the car still running, scanner immediately connected to the CAN and got the fault codes. There were a bunch and I am not sure how long they have been present and since I couldn't get the scanner to comm with the CAN before I couldn't previously reset all DTC. So anyway...here are the codes that I found stored:

ODB II (7 codes stored)
P1603 - PCM Internal dual port RAM communications failure
P0700 - TCS (MIL Request) /Malfunction Indicator Light/
U0101 - Lost Communications w/TCM
P0562 - Battery Low
P0700 - TCS (MIL Request) /Malfunction Indicator Light/
U0101 - Lost Communications w/TCM
P1603 - PCM Internal dual port RAM communications failure

SRS
U1415 - Implausible data
U1414 - Implausible ECU Network Configuration Data

ABS
C100A - LF Speed Sensor Circuit
U140E - Implausible Data
C2202 - VIN Mismatch
C2100 - Battery Disconnected
C101F - RF Speed Sensor
U0141 Lost communication w/Instrument Panel Module (FCM/TIPM) /front control module/total integrated power module/
U0002 - Can C Bus Off Performance

Chrysler Specific
P0700 - TCS (MIL Request) /Malfunction Indicator Light/
U0101 - Lost Communications w/TCM
P1684 - Battery Disconnected
P0952 - Autostick Input Circuit Low
P0613 - Internal Transmission Processor
P0562 - Battery Low

I believe that the battery low and disconnected codes can be eliminated at least initially. The battery is weak from the car not being driven but it takes a charge and holds it for up to 10 days. I do think though that it would fail a good load test, at least untill it was actually put in regular service. I have read that a low voltage battery can cause codes. I have not yet checked to see what the volts reading is across the terminals, tomorrow I will.

Initially I thought that having the VIN mismatch code and the implausible data faults was in indication the ECU had been swapped but never programmed for the car. But I cleared the DTC/codes and these faults have not reappeared (yet)

I did clear all the codes and when I restarted the car and took it for a drive, again it was stuck in limp in mode and only these codes that are now stored:

C100A - LF Speed Sensor Circuit
U0101 - Lost Communications w/TCM
P1603 - PCM Internal dual port RAM communications failure

So I now know this I guess, the transmission itself works, it shifts fine, the problem is electrical/harness or electronic related I assume. And the car seems to be asking for the LF ABS wheel speed sensor circuit/sensor to be checked and/or replaced. I guess its possible I have a stopped up wire somewhere in the TCM circuit/harness or the TCM in the integrated ECU is intermittent. I'm not sure about the P1603 yet but my Google collective research indicates this can be most often be caused by bad wiring like poor ground or loss of power feed/blown fuse or relay, or a faulty TCM/ECU itself.
  • Faulty TCM/PCM TCM/PCM programming error
  • Open or shorted circuit or connectors in the CAN harness
  • Failed TCM/PCM power source
  • Insufficient control module ground
I have no idea if the controller in the car has been programmed for the car since I had VIN mismatch and improbable configuration data faults stored initially.

I could sure use some sage advice at this point gentlemen...
 
#23 ·
I know I probably sound like a busted record, but have you checked the ground connections on the inside of the drivers fender? This is a KNOWN problem area on PT's because of the proximity to the battery. Corrosion is often a problem due to leaking battery gases. Other than that, I really don't know what to suggest. Have you checked the connector to the solenoid pack on the front of the transmission? Sometimes, they get loose too.
 
#24 ·
If you suspect that modules may have been swapped before you got the car, a good scan tool can read the VIN that is stored in the module.
Swapping modules may not be plug n' play and can irreversibly change a car's identity into the car that the module came out of. This can get expensive. The service manual warns against this, even a brief swap for a quick diagnosis or test.
A failing battery can cause a multitude of problems. I would do more than a terminal voltage test. I would stop by an auto parts store and have a comprehensive battery/starting/charging system test performed.
Any battery voltage that drops below 10 volts during cranking can cause invalid fault codes. You must diagnose beginning with a known good battery and good connections. Battery terminals can look good from the outside, but the joint between the post and terminal can be a high-resistance. Take the terminals right off the posts for inspection and cleaning if you haven't already. Hard scale may need to be scraped off as a wire brush isn't enough.
It still looks like CAN communications failure (the 'U'-codes) and implausibles/mismatches should be solved first.
You will want the 2006 PT factory service manual for the car. See what 'Possible Causes' the various fault codes have in common and narrow down the number of suspected culprits.
Are all the fuses and relays seated fully in their cavities? I have found loose IOD fuses.
 
#25 ·
Chuzz: I did check those grounds. In fact it was one of the first things that I did and I think that I posted this activity earlier. I actually took them off the mounting stud, cleaned them, inspected them, etc. and then remounted. They actually 'looked' fine with no signs of being tampered with or any corrosion whatsoever. But I did the work none the less. I feel they have been checked and are solid. Checking the solenoid pack connector, making sure its clean and not damaged in some was is now on the list.

Imperial Crown: Yes I have been reading about the VIN mismatch, improbable data codes and realize that the presence of these codes is a pretty clear indication that some module was replaced UNLESS these codes were stored because of poor communications quality across the CAN. Once I cleared ALL the stored codes only the three mentioned in my post above returned.

I do have the factory manuals and yesterday was the first day that I could get the car to scan so I'll be going through those steps as best I can w/o the benefit of the factory diagnostics tool which is so often the first or second step.

Yes, removed and re-seated all the fuses and relays, every one of them. When I got the car it had been run with the cover off the TIPM for some time and there was a bit of organic debris among the fuses. I have not however raised it up to examine the back side and double checked for corrosion or anything that looks like a gremlin...also I will see what kind of load and voltage my battery is capable of. Im sure it probably needs to be replaced or at the very least it needs to be run regularly to get it back to acceptable service levels. I did notice that it is only 18 months old. I think it's weak from sitting so much.
 
#26 ·
Please note from my earlier post:

I did clear all the codes and when I restarted the car and took it for a drive, again it was stuck in limp in mode and only these codes that are now stored:

C100A - LF Speed Sensor Circuit
U0101 - Lost Communications w/TCM
P1603 - PCM Internal dual port RAM communications failure
 
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