QuestionI was doing some more internet searching and came across someone this a similar issue. The response was to check the main ground connection for instrumments. Thinking about the only thing I did between it working and not working was having the car idle and putting the dash back on. Makes me think this could be it. Also during other tests it seemed like bumps would case the issue. Where would I check for possible lose ground wires, inside the car?
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Hi, Roland
Well once again I thought I had it fixed. I took the dash apart and fixed the solder on the tach per the instructions from this web site.
http://members.cox.net/dpeters30/97_sebring_dash.htm
The connection for the data bus on the blue plug all looked good.
I put in the input speed sensor and put back the original TCM. I test drove the car for the normal 5 or 6 miles across the Railroad tracks and everything worked fine. Tach/ speedometer/ transmission. No limp mode.
So the next night I let it idle while putting the dash cover back on. And you guessed it; the PRNDL went to all selected. So I drove it a little and the speedometer did not work at all, and I got a no bus message on the mileage indicator. I redid the key test and the codes were 12 66 66 55.
I guess it is time to take it somewhere? I think it is either the TCM or the wiring at this point. If it is the TCM that would mean that the one I got from a used parts place is also bad. I guess that is surely possible. The wiring really doesn’t look that bad.
Anything else you can think of that I could try?
Kevin
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Hi Rolland,
Thanks for the correction on the sensors. I do believe the one I have changed is the output sensor. So since it still goes into limp mode, I have a couple of follow up questions.
1. what does the input sensor do and could that be the possible cause, I guess it would be another cheap try?
2. Is it possible that I have a bad solder joint in the instrument "tach/speedo" cluster that could be causing the limp mode? Tach doesn't work at all, and I see that it was a common problem for 95 cirrus.
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Hi,
Of the 3 sensors, All are on the front of transmission. The 3 wire sensors are located on a mid level location. The 2 wire sensor is higher up on the front of the transmission. The 3 wire sensor farthest from engine color is Purple, black-gray, Red-silver. I'm guessing that the 2 wire sensor is really the output sensor. I'm still puzzled, it seems that the output sensor must be flakey, because the speedometer does occasionally drop, but this is the sensor that I did replace and usually the limp mode starts before any sign of the speedometer not working. Should I buy another sensor and try that at this point? Does the 2 wires from this sensor go to the TCM. It somewhat appears that they go to the pressure switch box.
Would the dealer diagnostic, for $100 really be able to pinpoint my issue?
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Rolland,
Thanks for the answer. I do need a little more of your expertise. Of the 3 sensors, 2 have 3 wires, Is the one with 2 wires the output speed sensor? I am having difficulty with the colors, I think the one with 2 wires, are green/brown and blue.
The no bus message was on the odometer. I did not get that this time. With the Key on/off/on/off/on I get 12 66 55 on the check engine.
The Speedometer works most of the time. I test drove it again and it would sometime drop to zero and then it would go back up to correct speed. The first time it went into limp mode, I think it was when I went over a railroad and the speedometer still worked.
I did not check wiring yet. If it is the wiring is there some way to replace just those and not the total wiring harness. I thought I read somewhere that was an option?
Also Is the part number 0406105 and 0406121 both part of the ECM? Is the TCM located on the top of the transmission?
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95 cirrus LXI, V6, automatic. History of vehicle. 195000 miles without really any issue, expect tach stopped working but occasionally would work if it was really cold outside. When car warmed up you could watch it slowly go to zero and stop working. The power steering would stop working if you accelerated fast. If you turned car off and back on the power steering would start working again. The anti lock brakes don't perform to good anymore, when braking hard on slightly slippery roads pedal pulse hard and there is some noise. On dry roads seems fair. The Real issue is with the transmission. Transmission seemed to start to shift a little hard and/or pause so I thought I would have it flushed and adjusted at a Dodge dealer. I had that done and short after that speedometer stop working and transmission would go into limp mode. Indicator for PRND3L are all on. If I try to get code with key, I get "no bus". I have tried a few things on my own after research mostly from all your past answers. I replaced the speed senor. I believe it was the input, I replaced the PCM with a used one (04606105 -07910) I believe that is the PCM. Would it help to change the ECM 0406121 ? Should I replace the output speed senor? Car runs great, I can lives without the power steering issue fixed but can't seem to get it not to go into limp mode. Of course after I have the battery disconnected it works for a few miles. Almost seems like bumpy roads may be causing it to go to limp mode. Any ideas would be great.
Kevin
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Hi Kevin,
Those are several questions so I will mention a couple of simple things for two of them and focus on the third.
The power steering may just be a too loose drive belt so check that and increase the tension if warranted. On the brakes, those are vacuum assist so check the vacuum hose to the booster and if none then check the pads on the front.
On the trans: does the speedometer work now? If not, then either the Output Speed Sensor is not working or the wiring of it to tansmission controller is faulty. The signal wire is light green/violet and goes to pin 14 of the trans controller, while the ground wire is dark blue/red and goes to pin 13. So if those connection between the plugs are o.k. I would think a new sensor might get the speedo and the shifting problem back in line. If the speedo works then forget about the sensor being the cause of the limp mode. Instead see below for info about code readout of the trans controller memory.
But one caveat is the "no bus" message. Is that what is readout at the odometer, or rather do you have a code number that you can tell me? It would be useful to know more specifically about which unit of the bus system says that it isn't getting the bus messages. I would not change the powertrain or the transmission controller until you have exhausted the other possible reasons. There are compatibility and program issues that complicate those kinds of changes. I would stick with what came with the car. The term for the engine controller is either 'ECM' or 'PCM', while the transmission controller is the 'TCM'.
On the code readout, I believe that your car is still using the OBD-I system, and you may therefore have two separate readout approaches, one for the engine (a plug for a reader under the hood or the check engine light that you readout via the ignition key) and one for the transmission (a 'data link' connector plug under the dash that also requires a reader and a different plug from the one that is used under the hood). The trans readout may be something that you will want to do to see what code numbers and names are revealed as to why the trans is going into limp mode IF the output speed sensor/speedometer doesn't correct the problem. Let me know the codes and we will go from there.
Roland
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Hi Kevin,
The input and output speed sensors are on the side of the trans that faces the front of the car, both about midline height. The input is near the turbine (interface between the engine and trans) and the output is at the very end of the trans on that same side just to the outboard of the vertical shifter shaft. The latter sensor has 2 wires (light green/violet and dark blue/brown). If the speedo is dropping out and the trans goes into limp right after that I would suspect the output sensor is kaput.
The 66 code means no data communication from the trans or from the body controller. But if it is gone then I would not worry about that.
The wiring can probably be spliced or repaired if necessary. But more likely the output speed sensor is flakey.
The tcm and ecm are on either side of the power distribution center under the hood. The ecm is outboard of the 'center' and the tcm is inboard of it. The box on the front of the trans with the multipin plug is the solenoid and pressure switch box. I don't know about the part numbers.
Roland
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Hi Kevin,
We have a misunderstanding about 'mid' and 'high', and 'front' and 'side'. I said that the sensors were on the side of the trans that faces the front of the car. So that is the "side" of the trans. The front is the end that connects to the engine. The "rear" is a flat surface at the other end. There are two plugs close to one another at the same level as the bottom of the solenoid box, fairly near the rear of the trans. Those are for the park/neutral safety switch and the transmission range selector switches (not sensors). Then higher up are two 2-wire sensors that look quite similar. One is near the front of the trans (near the engine) and that is the input turbine speed sensor. The other one is at the same height but near the end of the trans (the rear end), on the other side of the vertical shifter rod. That is the output speed sensor that helps control the trans shifting and also runs the speedometer. I don't think you have seen it yet, so look again.
I can't be sure if the output speed sensor is causing your limp in, but it can be a cause if it fails. And because its signal runs the speedo, that might be why the speedo isn't registering from time to time.
A diagnostic readout of the trans controller would be useful. If the diagnostic plug under the dash has 16 pins then that is the contemporary OBD-II plug which should be able to give both the engine and transmission codes on a good reader. If it is a 6 pin plug then it has to be read with a Chrysler DRB II reader at a dealer in all likelihood. So if you have the 16 pin plug you might get a free readout at an Autozone store, or at least you could shop around to any repair shop that has a 16 pin reader and the cartridge that covers your vehicle and that might charge around $40 for the readout of the transmission memory. Make sure that you specify that you want the transmission codes, not the engine codes.
Roland
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Hi Kevin,
Yes, the input sensor's speed is compared to the output sensor's speed and if they disagress for the gear that is being used, then that means clutch slippage which indeed is the basis for going into "limp". It also has a specific fault code for that, so if you get a memory readout that would confirm such a situation. If you want to take a chance that the sensor is bad and that is why the ratio is wrong, then go ahead and buy it without a readout.
Sure, if the data bus connection to the cluster is flakey it could throw off the other units that are part of the system, so check the connections between the socket and the circuit board at pins 7 and 8 of the blue plug at the cluster as those are for the data bus. Just reheat the joints with a solder pencil.
I am curious to learn if you find something that fixes the limp.
Roland
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Hi Kevin,
On the wiring, there are about 34 wires on the transmission control module that you could trace and verify and also maybe do the same thing on the body control module. You might find one with a connection problem which would be the cause of the 66 codes. If you don't have any confidence in the TCM then replacing that with another one seems reasonable. Other than those, I have no other ideas.
I have the '96 wiring diagrams but not the '95, but they should be identical. If you don't have those in detail let me know. I can xerox and postal mail them to you if you would be willing to cover my cost (8 cents per side plus the postage).
It is interesting that it worked for a while.
AnswerTwo on the left strut tower, one on the rear of the transmission, right strut tower, left kick panel(in front of door opening), front cylinder head, right center instrument support panel (under the dash), under gearshift,
center of decklid opening, center of deck lid. Those are them.
Roland
