QuestionQUESTION: I have a 2001 PT, 140,000 miles. Recently I suddenly got a whine that sounded like a car might sound if it was having fluid problems or something with the transmission (based on the noise it made the one time the shop didn't put the filter back on ... it didn't get drove any further then from the shop to the parking lot and back with that problem and it was months ago).
So my first thought was since they screwed up filter, maybe wrong fluid, so I dropped the pan, checked the filter and changed fluid. No dice. I pull the codes, I get the gear ratio wrong ones a P1782 and P1787 ... I think makes sense might be the solenoid. I replace the solenoid pack, put it back together and still have the same symptoms, if not a little worse.
Any ideas of 1. something I might have missed / screwed up doing solenoid. 2. what else might be causing it 3. what I should be looking at to maybe try to diagnose in my garage to avoid the costly adventure of having it towed into a shop and pay out the nose for them to tell me it needs a rebuild (since I doubt it does, it was a sudden onset problem)
I did notice something interesting, that if I unplugged the solenoid pack, or didn't have the eatx relay installed the car acted the exact same way. I'm thinking maybe it's the TCM.
I'm not sure what a dealership can do more then I can aside from charging me an arm and a leg and pulling the transmission. ... which at that point the car becomes a liability because i'm not going to put 1000's of dollar into a 2001 car.
ANSWER: Hi Robert,
I am unclear if the codes are also the gear ratio code (which ones?) in addition to the 1782 and 1787?
The latter two are related to the 2-4 pressure switch circuit (could be due to the pressure switch sense circuit being shorted to ground or battery, defective pack but you replaced that, loose valve body bolts, defective TCM, or of course internal damage) and to the OD pressure switch circuit (could be OD pressure switch sense circuit shorted to battery, defective pack, or of course internal trans problem). I am not surprised that the symptom is also present if you disconnect the pack or the relay it is unchanged because limp-in mode is likely what you are 'in' anyway so pulling the relay, etc. is essentially self-initiated limp-in.
I would check the wires between the TCM and the solenoid pack for possiblie shorts to battery or ground or 'opens'. The try a rebuilt/used TCM. I assume that you bought a reliable pack and installed it properly. Let me know if you need the wiring details.
With 140k miles on it, I would not be surprising if there is internal damage to the clutches, etc. Was there much debris in the pans when you dropped them? and how far had you gone since the last pan drop (which would have removed any such evidence)?
Roland
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QUESTION: P1768, P0750 are the codes that are present on the TCM right now. I cleared them and continue to hear the whirring sound. I let it run for a minute in the garage. Plenty of fresh new fluid in it. Would it need a drive to learn since I did replace the solenoid pack or is that just asking for trouble?
ANSWER: The 0750 says the Low/Reverse solenoid is not properly responding when tested, which is done immediately with the key being turned to the run position. It is continually tested every 10 seconds.
The 1768 says that either the trans relay is not closing when requested of its points are not conducting well. The tcm looks for there to be 12v on its pins 56 when the relay is closed and if it doesn't see it the code is set.
You could try switching out the trans relay with another one of the same part number in the power box under the hood. And you could check the wire from tcm pin 15 light green to the rear/driver side pin of the relay socket, and that the relay coil ground wire front/passenger side pin is patent to ground which is the circuit that activates the relay coil. Also verify you have a solid 12v on the rear/passenger side pin which comes directly from the battery via fuse 15 which you should also look closely at to be sure it doesn't have a subtle crack in its wire,
It could be that both of these codes are correct so you need to check out both. The 0750 could be a flakey connection between pin 7 of the solenoid pack light blue wire and pin 20 of the tcm, so check that out. And of course it could be the solenoid itself is bad. Earlier codes pointed to pressure switch issue, so it makes me wonder if the replacement pack is defective. I doubt that you would correct any of these codes by driving it. The trans will learn by itself or you can do a quick learn procedure, AFTER the control are fixed and there are no codes.
Roland
---------- FOLLOW-UP ----------
QUESTION: Well, I think I am at an impass, cleared the codes, started it, ran for a bit, let it warm up, went through the gears. Took it on a test drive, only code that came up was P0700 and P0732 ... no electrical trouble codes or anything. Wires all check out. Maybe I have to run it longer to generate the 1768 or 705 codes? I thought about it and yesterday I did run it with 1. relay out to check voltages and 2. solenoid pack disconnected to also check for voltages. Maybe the codes could be left over from then. Obviously the TCM is talking to the sensors to get the gear ratio code. Maybe something go broke inside while the old solenoid pack was failing. Going to see how much a valve body is I guess. The joys of living a long way from the nearest shop and being broke.....
AnswerHi Robert,
I too am stumped as to what your next move should be. The 0732 is saying a 2nd gear ratio error is present which can either be one of many types of internal damage OR it could be a solenoid pack issue too if you concurrently have one of those codes. I hope you can avoid a rebuild.
Roland
