QuestionQUESTION: Hi Roland. I’ve been browsing your answer history for a 1998 Chrysler Concorde, (with 3.2 engine) transmission problem I’m having. I found a lot of useful information and am using it to further my troubleshooting efforts. But, I have not found my exact problem so I thought I write and see if you could further direct me.
This is a friends car and they had simply asked me to “get it ready for the winter” and to check the reason for the “check engine” light coming on. The car had sat practically all summer. I put a battery on it, got it started and began driving it home. Before I got to the first stop sign, I noticed the transmission wasn’t shifting properly. I realized pretty quickly that the tranny was in the “limp’ mode. The other thing I noticed is that the speedometer wasn’t working.
Having some history with this from a 1994 intrepid, I automatically chose to replace the transmission. I bought a low miles used one and installed it. I still have the same problem. Trans is stuck in limp mode and speedo doesn’t operate. So, I assume I have a different problem.
I ran the ignition key code reader as suggested in your information, but only got a P1684, which obviously made sense as I had the battery disconnected while performing the trans exchange.
I took the car out today and drove it in limp mode at a steady 3000 or so rpm and finally got the computer to set the fault code (engine light) again. This time I got a P0700, which my manual says is EATX Controller DTC present. The definition for that code description is very convoluted and doesn’t really direct me to anything specific. I had found similar communication of that fault code in a couple of different places in your answers, but they contradicted each other from my perspective. One comment was that the P0700 was simply an indicator of additional codes, another comment stated that it might point to a problem with the transmission control module and/or solenoid pack or relay. I am going to further check that out and see if I can determine anything. Any further consideration that you have on that fault code would be appreciated.
Another thing to note, When I swapped transmissions, I used all of the sensors that came with the replacement unit…so, in one sense I assume I can rule all of those out since they were “replacements” per’se. Since I have the same symptoms as before, I assume I should be looking elsewhere and I believe this fault code also points me in another direction?
Where do I find this transmission control module. My book shows the circuitry in the electrical section, but doesn’t show the location of the module.
I’d appreciate any other thoughts or ideas and direction you can provide on these symptoms. Please let me know if you have questions.
Sincerely,
Marty
ANSWER: Hi Marty,
You can switch out the transmission control relay in the main power box with another one there with the same part number and is not critical (one of the wiper relays) in order to see if it something so easy as that.
If you only got the 0700 code via the ignition key jiggle, then I would suggest that you go to a nationwide autoparts store, such as Autozone, and ask for a free code readout of the engine AND the transmission memories. The trans codes are not likely to be revealed by the ignition key approach. An independent shop may charge up to $40 for a readout if you can't get a free one. Call ahead.
Once you have the hidden code we can go from there.
Roland
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QUESTION: Hey again Roland.
I understand what you're saying about the hidden codes. I will plan on getting that done. In the mean time, I did a little digging since my last message and:
1. The TCM relay seems to be fine. I found it and swapped it. Same response.
2. I found the TC module and pulled it out so I could get access to the wires. Via my manuals electrical schematic, I was able to test the TCM relay above and verify it was sending power to the TCM.
3. The one thing I ran into, and question, is the output/input speed sensor circuit. According to my schematic, the TCM should send voltage out to the speed sensors. Terminal 14 for output sensor and terminal 52 for input sensor. Terminal 13 is a common ground to both. I could not get any voltage readout on either of the wires for the output/input terminals. I verified the ground and it seems OK. Should the TCM be sending some sort of voltage out to the speed sensors for them to work, or does the sensor magnetically generate it's own voltage when being excited and send voltage as an input back to the TCM at these terminals?
I tried to verify this a couple of ways....a) simply had the key on testing for voltage, b) started the car and tested for voltage, c) jacked the front end off the ground, put the car in drive and allowed the trans/wheels to operate and test for voltage. In none of these circumstances was I able to get any kind of voltage on these two wires. I also tested these two circuits using a remote battery ground as well as the internal ground wire going to the TCM.
Any thoughts about this finding.
Thanks,
Marty
ANSWER: Hi Marty,
My belief is that the sensors produce an electical pulsation proportional to the rotation of the shaft, but as to the voltage waveform or its intensity I have no knowledge. I would be inclined to look to the fault code readout for direction. The codes for those sensors' faults are 0720 and 0715. Without knowing the sort of signal one is dealing with there is no certain way to assure that a give voltmeter will be able to detect it. The sensors costs are in the range of $100 each so a readout, particularly if free, would be worthwhile rather than to "throw parts" at them in the hopes of hitting on the cure.
Roland
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QUESTION: Hi again Roland. Sory for the delay in getting back to you. I've been very busy.
My son drove the car to Autozone today and here are the fault codes/definitions as determined by their reader:
1. P0700, Transaxle Control System Fault
Explanation = "received a signal that the transaxle control module has a fault"
Probable cause = a) shorted or open circuit within the transaxle, or b) failure of transmission control module.
2. P0500, Vehicle speed sensor circuit condition
Explanation = "the ECM has detected a fault in the vehicle speed sensor circuit"
Probable cause = a) Poor electrical connnection or short circuit condition, b)failed vehicle speed sensor, c) Drive gear mechanical fault.
3. P0731, ratio error in 1st gear
Explanation = "the ECM has detected that the transmission input RPM does not match the transmission output RPM under known conditions"
Probable cause = a) check other service codes first, b) TSS error, c)poor electrical connection, d)internal transmission fault.
OK...so that's where I'm at.....Let me know what you think.
Thank you,
Marty
AnswerHi Marty,
I would check out the output speed sensor circuit wiring: The light green/white wire should be continuos to pin 14 of the tcm, and the dark blue/black wire to pin 13. The tcm is just in front of the pcm which is just in fromt of the power distributiion center. The 0731 may be due to the same issue of there being no signal from the output sensor seen at the TCM. If the wires show continuity between the sensor and the tcm plug, then I would replace the output sensor. You may have had failed units on both the old and the used transmissions.
Roland
PS I would appreciate your 'rating' of my answers using the tab below to do that. Where you see the question about a nomination of me to be 'volunteer of the month' if you would consider a 'yes' response that would be appreciated. Thank you
