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Post by joe691 on Feb 25, 2003 13:25:06 GMT -5
i have 2000 ms just turned 60k miles, just today it started skipping at 3500 rpms as i accelelerat. truck still drives fine except for the horrible vibration between each up shift. HELP
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Post by Joel_CA on Feb 26, 2003 3:58:00 GMT -5
You may be either suffering from a "Shift Flare" which can be repaired by a simple reprogramming of your Powertrain Control Module, or....your torque converter clutch is starting to deteriorate because your either using some ATF OTHER than the recommended Mitsu SPIII (seen this happen many times folk- cant express how important I feel it is to use the correct fluid), or failed to maintain your fluid condition and/or level . First thing to do is verify your fluid level and condition...should be at the top notch of the the level indicator after a few miles of driving...and should also be a transparent dark red. Either way...your local dealership should have the tools and reference materials to repair your tranny's condition. If you need reference to the PCM reprogramming, let me know!
Joel, CA
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hal
Full Member
Posts: 51
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Post by hal on Feb 26, 2003 5:07:20 GMT -5
Either way...your local dealership should have the tools and reference materials to repair your tranny's condition. If you need reference to the PCM reprogramming, let me know! Joel, CA I am interested! I get that shift flare once in while. Do I just go to the dealer and have them download the new software?
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Post by Stod on Feb 27, 2003 2:23:29 GMT -5
Trans shift flare Mitsu Technical Service Bulletin is:
TSB-01-23-007
Cheers, Stod
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hal
Full Member
Posts: 51
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Post by hal on Feb 27, 2003 22:00:37 GMT -5
Trans shift flare Mitsu Technical Service Bulletin is: TSB-01-23-007 Thanks! I went to dealer today and they uploaded new PCM program. Tranny shifts much better. Very positive shifts! Also noticed that PCM decides better when to hold a gear or shift.
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Post by Joel_CA on Feb 28, 2003 10:51:50 GMT -5
Thanks! I went to dealer today and they uploaded new PCM program. Tranny shifts much better. Very positive shifts! Also noticed that PCM decides better when to hold a gear or shift. That's great news...At 60K though, I'd highly recommend a transmission flush (not drain and fill)for more peace of mind. Joel
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Post by joe691 on Feb 28, 2003 13:25:55 GMT -5
i am the guy with 60k and the skip. i havetaken your advise about the PCM reprogram to my dealr, he says thats not the problem but rather the "low detection switch" is stuck and will cost me $165.00. I did the transmission flush for $200.00 and it did not solve the issue. What do you all know about the "low detection switch"??
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Post by Stod on Mar 1, 2003 2:30:47 GMT -5
Joe,
Did the dealer do the Shift Flare reprogramming?? If you need a copy of it to take to the dealer, I'll email it to you.
I don't know anything about the "low detection switch". If such an animal exists...it sounds like it's an "external" part. The 60K powertrain warranty seems to only cover from the block/case through internal parts. Could be another MMSA "gotcha".
Good luck and Cheers, Stod
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Post by Joel_CA on Mar 2, 2003 20:16:16 GMT -5
That's another possiblilty although it is very rare to happen. IF you 4 lo detection switch thinks you are in 4lo even though you're actually in 2H, it will cause the PCM to activate a fuel cutoff at approximately 3k+ RPM's- unfortunately, that is roughly where the transmission torque converter usually locks up (which is why I went that direction). This fuel cutoff would result in a considerable jerking action which most customers would relate to the engine. Sorry if I lead you down the wrong path...perhaps I should've asked for a more detailed explanation of syptoms.
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Post by Stod on Mar 3, 2003 1:56:35 GMT -5
Joel,
That brings up another question. My 4wd indicator switch was defective (4wd indicator on the dash would flash and the antilock light stayed on...maybe kept flashing, I can't remember now!). Anyway one of the techs was passing through when I was having a conversation with the service manager and made the comment..."Oh yeah, the high/low switch".
Are there TWO switches? The 4wd indicator switch and a high/low switch.
The one replaced on mine was mounted on top of the transfer case. Is there is a second one, and where is that located?
Thanks and Cheers, Stod
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Post by Joel_CA on Mar 5, 2003 4:21:26 GMT -5
There are 3 switches. 1 in the front diff case (Freewheel engagement switch) and 2 in the transfer case 2/4 WD switch and 4Lo switch. Most problems occur in either the freewheel switch or the 2/4 WD switch. Failure to either can result in an ABS light warning...as the ABS computer gets confused as to which mode to run in. (the multimode ABS changes how it responds to wheel slippage based on whether it's in 2wd or 4wd- if the switches don't jive, it will set a code). The problems with the switches can be prevented by switching the transfer case into 4wd on occasion as this will prevent the switches from sticking into a certain position.
Joel, CA
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Post by Stod on Mar 6, 2003 0:02:48 GMT -5
So, a 4Lo switch problem would not cause an ABS light situation? What would be the indicators of this problem?
Freewheel switch...what's that, since we're not talking about locking diffs (or are we?!)?
Also, so these are mechanical switches, then right?
Thanks Joel. Cheers, Stod
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Post by Joel_CA on Mar 6, 2003 1:07:35 GMT -5
It may...but it's is not usually the cause, since most people hardly ever go into 4 lo to get the switch stuck. One of the indicators of a sticking switch is the constant flashin 4WD indicator lamp.
The freewheel switch in the front differential monitors whether the freewheel clutch has engaged. In 2wd, the RF axle half is disengaged from the front differential. With the RF disengaged, the LF axle will just spin the planetary gears inside the differential as the truck rolls down the road. The ring gear itself will not rotate at this time- this is to reduce drag in 2wd mode and allows the ability to shift on the fly. With the transfer case in 4wd, power is sent to the front diffential- rotating the ring gear. If the front freewheel clutch fails to engage, all of the power to the front diff will be "unloaded" to the RF (disconnected) side (similar to a conventional diffential unloading with one wheel off of the ground. Once the mechanical 2/4 WD switch detect the transfer case is in 4wd mode (4wd light starts to flash), it signals the freewheel clutch actuator to engage the freewheel clutch. Once the clutch is engaged, the freewheel switch will detect it (and the 4wd indicator should remain lit). That's pretty much it in a nutshell...there's waayyy more technology behind it..but my fingers are getting tired!
Joel, CA
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Post by Stod on Mar 7, 2003 15:59:00 GMT -5
Thanks, Joel.
Cheers, Stod
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Post by 2000ute on Mar 9, 2003 4:01:12 GMT -5
this is for joel, ok, way back to the shift flare issue, i have had some extremely hard shifts(flares?,i don't know)but am otherwise satisfied with the auto and have went to the trouble of using the appropriate mitsu spIII fluid, but i really like the redline products, i use 10w40 full sn. oil, water wetter and their fuel cleaner(i forget the name) and was thinking about using their gear oils and an atf equivealant for my 2000. bad idea?
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