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Roland,
I have been looking on line for specific answers related to my problem because I have already spent over $1K trying to get it fixed, but I have not seen any definitive answers. Here we go:
1995 Chrysler Cirrus 2.5L V6 w/Auto Transaxle, 3 Spd + OD. Mostly, the car runs fine. Intermittently, the transaxle will drop into the Limp Home mode, where it will not shift out of first gear. An AAMCO center was unable to fix it. The ECM, TCM, and Solenoid pack have all been replaced. I was assured by AAMCO that there is nothing physically wrong with the transaxle and it does not need to be replaced. They suspect an electronic problem which they were not able to find. Usually, the vehicle will run fine from cold, and only has the problem after stopping (as to go shopping) and then restarting after 1/2 hour or so. Vehicle will immediately be in limp home mode and stuck in first gear. If I pull over, shut it off, and start it back up again, the problem will usually correct itself. However, recently it has developed new symptoms. While driving, at 50-60 MPH, the transmission will drop out of gear (selector still in drive)and will not re-engage until I slow to 30 MPH or so, at which point it bangs into first gear and stays there. Pull over, shut down, restart, and it is usually OK. Then, this morning, which was the first fairly cold morning so far (45 deg. F)the vehicle was in limp home mode from the moment I started it. Tried twice to restart, with no luck. Drove until the engine warmed up, restarted, and everything was fine for the remaining 40 minutes and 30 miles of my commute. Supposedly, AAMCO checked all of the sensors and the wiring harness and found nothing wrong. I don't want to spend another $1k or more letting shops take potshots at the problem. Can you help me? I am reasonably intelligent about cars and do most of my own work, so please be as specific as possible and don't worry about being too technical. Do I need to buy a scan tool? That will be cheaper than the first repair bill I will have at a new shop. Please advise. Thanks.
Answer -
Hi Art,
My knowledge of the electronic transaxle is based upon reading the Chrysler shop manuals. I wonder whether AAMCO actually performed a readout of the TCM for stored fault codes? There are 45 different codes, and if one or more of them show up it will give you some direction in further diagnosing the source of your problem. I have a Chrysler Diagnostic Readout Box, but the cartridge only covers thru '94 year model and I'm in the SF Bay area so that limits my ability to help you with that test. But I think a Chrysler dealer's shop might be worth asking as to how much they charge to put their DRB II on your car and give you a readout. I have a Chrysler text that discusses each code and the possible causes for it, so you wouldn't have to have that part of the analysis pursued by the shop, just get the numbers of the codes. The other diagnostic test is to measure the hydraulic pressures at 6 different ports on the trans with the engine running at 1500 rpm. Again, I have a table the gives what the reading should be.
Other owners of this trans have reported that there was a saluatary effect resulting from draining, changing the filter, and refilling the unit with Chrysler branded fluid (everyone who is knowledgeable says don't use a substitute fluid) but that may have already been done (except for the question of the brand of fluid used?).
Getting to the truth of what is the problem requires using all the diagnostic tools that are available, so if you could get the codes and identify any off-value pressures you might be on the way to diagnosing and repairing the unit.
Roland
Follow-up
Thanks for getting back to me so quickly. I asked and was assured by AAMCO that they used the correct Chrysler ATF. I know how to access trouble codes via the ignition switch and the check engine light. However, I also know that transmission codes cannot be accessed in this manner. Does that mean that the transmission codes are not stored? If the problem is intermittent, does that mean that the vehicle needs to be driven with a scan tool connected and have the problem occur, so that the scan tool can log the codes? Or can these codes be accessed even if the problem is not occuring at the moment. AAMCO did look at the transmission diagnostics, but the problem never actually occured while they had the vehicle in their possession. If I buy a good scan tool, I can get these codes myself, yes? And, if necessary, I can drive with the tool connected and wait for the problem to occur, yes? I am hesitant to trust a Chrysler dealer with an oil change, much less transmission diagnostics! Thanks again for your help.
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Hi Art,
The TCM stores the fault codes that it detects. It also reports the number of key cycles since the code was observed to give an idea of whether it is a "hard" code (happened again within the last 3 cycles) or an intermittant fault code (more than 3), which means that the problem may not be present at this moment and to observe it in action you have to drive the car and wait for the fault to recur, using the test tool as a monitor. The unit plugs into a diagnostic connector located on the driver's end of the dash at the lower edge. The test tool has to have the CCD Bus plug (which is different from the plug in the engine compartment that monitors the ECM). So make sure that any test tool has the 6-pin (3 pins in 2 rows) CCD bus connector. If AAMCo had the correct test tool they should have been able to readout the historic codes that were generated while you were driving the car. You can run the car with the test tool connected if necessary. I wouldn't dismiss the Chrysler dealer, they would have the most experience with this transmission. At least inquire about the cost of having them readout the codes. Can you inquire of AAMCO whether they readout the codes, and what they are? If the trans goes into limp-in it is synonymous with a code being detected and set in the memory(though not all faults will cause limp in).
Roland
Good Morning, Roland. I have a question about the scan tool that you may be able to help me with. For lack of any other info at the moment, I was looking in a JCWhitney catalog last night for scan tools. None of the write-ups for any of their tools mentioned a CCD bus connector or plug. All of them talk about OBD-I and OBD-II and cables for GM, Ford, etc., but nothing specific about a CCD bus plug. Do you know whether or not this plug is a typical component of one of these scanners? Can you recommend a company or scan tool that you know has the necessary connector? If I look on line, rather than the catalog, I might get more info, but I thought maybe you could point me in the right direction. Thanks.
AnswerHi Art,
My understanding of the Chrysler system that applied thru '94 (and maybe later, though I can't be certain) is that the trans is read via the CCD plug and the engine is read via a different diagnostic connector. In fact I have both connectors for my DRB. I can't be sure, but why not look for the diagnostic connectors on your car? The engine one is usually located on the driver side near the inner fender and relays and while it has 6 holes, they are not linearly arranged. The other one, the CCD is at the driver's end of the dash, either behind a removable panel or hanging freely underneath the dash. It is smaller and has 6 ports three on a side. So unless a unit has both the engine plug and the CCD bus plug and you find both kind of plugs in the car you will need both if you want to do the tranny readout and analyze the engine in the future.
I am not certain it is worth buying a scan tool to get the code readout. Have you asked how much a Chrysler or Dodge dealer would charge to do it? It only takes a few minutes to do. I paid $400 for my DRB II on eBay, but to tell you the truth I haven't used it that much as yet other than to record the operating characteristics in the present 'no problem' mode for possible future reference.
Roland
