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Old 07-12-2007, 12:37 PM   #1
bbohica
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2000 Rodeo Transmission stuck in Limp mode.

My tranny is stuck in limp mode. I can manually shift it, but it won't shift on it's own. The 'automatic' part of the automatic transimission is definitely not working right.

I searched and checked for the usual suspects, low battery or alternator output (measured over 14v at batt. when on), and the range selector switch. I removed the switch, took it apart, cleaned it up, and reinstalled it. It looked like it was in decent shape inside, although it appeared to have had a bit of oil of some sort that had leaked into it. There was a bit of oil on that side of the tranny, around the gear selector and switch, but not enough to actually drip as I don't have any stains on my driveway where I always park. The only thing I haven't checked is the atf fluid level, as I can't seem to find the my wrench that will take off the fill nut. I'll get that figured out tonight.

The tranny hasn't been taken care of like it should, I've had the fluid replaced two or three times over 100k of ownership, but I'm not sure about the filter. Would the need for a filter and fluid change cause it to go into limp mode? Any other suggestions of things to check? Also, it's not throwing any CEL codes either.

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Old 07-12-2007, 01:14 PM   #2
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Re: 2000 Rodeo Transmission stuck in Limp mode.

Where do I find the transmission control module on a 2000 rodeo? I've read to check the connectors and a few voltages at the TCM....
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Old 07-12-2007, 01:31 PM   #3
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Re: 2000 Rodeo Transmission stuck in Limp mode.

you should check the trans fluid, but...

limp mode is almost always a result of electrical/electronic problems, and *very* often the charging system, since the at electronic components and computer will not function outside a rather narrow range, either too low or too high <9, >16 volts.

computer location on the rodeo, i don't know but maybe could check a manual, but i'm sure a rodeo owner will chime in

//bc
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Old 07-13-2007, 11:12 AM   #4
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Re: 2000 Rodeo Transmission stuck in Limp mode.

Checked the fluid last night... It definitely needs changed based on the color. It seemed to be about a quarter to a half quart low as well. I pumped two quarts in and let the it continue to overflow some dirty oil out the fill hole until it stopped. I only had two quarts on hand so that was all I could do for now. Still in limp mode though.

Anything else I should check besides the TCU that I haven't found yet? Is it time to take it to the stealership? I usually take my car to a local shop (not a stealership) and they do a decent job on most things but is this something that they likely won't be able to debug or solve? Will I be better off taking it to the stealer?
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Old 07-13-2007, 01:22 PM   #5
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Re: 2000 Rodeo Transmission stuck in Limp mode.

you are confident that you've checked the charging system for sure? including the wires and connectors?

//bc
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Old 07-13-2007, 03:22 PM   #6
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Re: 2000 Rodeo Transmission stuck in Limp mode.

I wouldn't say I'm supremely confident... I've had problems with battery connector corrosion in the past, but last year I replaced the battery and the positive cable terminal. I removed both of the terminals, and cleaned the batt. posts and terminal insides. Tightened them both down good. Beyond that I haven't done much besides measure the voltage being over 14V when on and idling.

How do I do an alternator "under load" test? I'd like to measure the voltages at the TCM if I can find the thing. I have the 'shop manual' on CD somewhere that I'm sure will show me. I have to dig it out, it's packed somewhere as we're in the middle of moving.

Wife dropped the thing off with the 'local shop' today so we'll see what they have to say.
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Old 07-16-2007, 02:28 PM   #7
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Re: 2000 Rodeo Transmission stuck in Limp mode.

So the shop we took it to says my "transmission clutch" is out and it is slipping. I mentioned to them that it is in limp mode and it will act like that, and they said that if it was truely in limp mode then there would be CEL codes, and that it probably needs a transmission rebuild.

I don't know much about automatic transmission clutches, but on manual clutches, when they go, you can stomp it in any gear and feel it 'slip'. Wouldn't this do the same? When I shift to L, it doesn't seem to slip when I stomp it, or in 2-3...
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Old 07-16-2007, 04:46 PM   #8
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Re: 2000 Rodeo Transmission stuck in Limp mode.

Quote:
Originally Posted by bbohica
So the shop we took it to says my "transmission clutch" is out and it is slipping. I mentioned to them that it is in limp mode and it will act like that, and they said that if it was truely in limp mode then there would be CEL codes, and that it probably needs a transmission rebuild.

I don't know much about automatic transmission clutches, but on manual clutches, when they go, you can stomp it in any gear and feel it 'slip'. Wouldn't this do the same? When I shift to L, it doesn't seem to slip when I stomp it, or in 2-3...
first i'll say i'm not totally confident in diagnosing from this distance, and AT's can be tough anyway.
but...i can tell you that the AT limp mode will often not set a CEL.
and i *can* tell you, from what you have written, that the shop is full of it.
if it were a clutch, you would have the same problem with shifting it manually.
maybe it does need rebuilding, but i wouldn't go there anytime soon, and not from what you have written.
instead of chomping down on it in L Low to test for clutch slippage find a long incline and get it up to 3 third manually and then do it,.

i'm still betting you have an electrical problem. charging problem. alternator. or connectors. you didn't mention -- have you followed the battery ground wire to the body/frame, removed it, cleaned shiney bright and reinstalled?



//bc
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Old 08-21-2007, 03:16 PM   #9
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Re: 2000 Rodeo Transmission stuck in Limp mode.

Well... I'm still having problems... After driving the car around in limp mode for a few weeks (it's my only car) it started acting worse... it wouldn't shift up into '4th' gear anymore... it would jump around in gears... all strange stuff. I finally took it to a transmission shop and as I expected, they said the transmission needed rebuilt, torque converter or something. So.. a ton of money later, they tell me "the transmission is functioning properly and it shifts through all the gears when externally tested, but you have an electrical problem and it's stuck in low gear"!!!!!! They tell me that they have done their job and I need to come pick up the car and pay up. Not having any other option, I do it.. and take it a few blocks up the road to the Honda dealership who agreed to look at it for me. They call me today and say "Everything seems ok electrically, there must be something wrong inside the transmission"...

So... what do I do now? I can take it back to the transmission shop but I doubt they will be more helpful... perhaps I take it to one of their other shops to get a new perspective on the problem? The honda tech is writing up a report of what he did so when I take it back to the trans. shop they will know what has been tested.

To answer your question above, no.. I haven't followed the ground wire to the chassis and cleaned it up... I can still try that I guess when I get it back. Isn't there a list of points to measure voltage at, on the transmission computer, that tells you if you have a power problem? I've seen that list somewhere.... Where is the transmission computer anyway?
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Old 08-21-2007, 07:40 PM   #10
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Re: 2000 Rodeo Transmission stuck in Limp mode.

I hate to hear stories like this. I'm sure you searched and found many posters have gone through the same issue. Well, the issue being having tranny rebuilt and STILL having the same problem.

As many members will tell you, besides testing the voltage, they would have dropped the pan and visually checked the fluid and the filter. Perhaps throw in a partial fluid exchange at home.

I sincerely hope that your rebuild came with some sort of warranty. Go back to the shop and demand they stand behind their work. Was the work done at a chain shop?

You mentioned that the shop said something about the TC? Replacing a TC isnt that expensive compared to a rebuilding a tranny.

I know none of this helps you, but I would go back to the shop that rebuilt the tranny. Keeping going back until you get it done right.

I had my tranny rebuilt a year ago and it came with a 3yr/36,000 warranty.

**NOTE:
My tranny went into limp mode before it was rebuilt. Also, there weren't any CEL's, but I did have a stored code.
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Old 08-22-2007, 12:03 AM   #11
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Re: 2000 Rodeo Transmission stuck in Limp mode.

The rebuilt came with a 2 year 24k warranty and was done by that nationwide shop that Terry Bradshaw advertises for...... If it's electrical, I'm probably going to have to fix the darn thing myself... I'm an electrical engineer and I have the shop manual so I'll probably just have to print up all the wiring diagrams and schematics, and start probing until I find something that looks fishy... I just don't have the time to spend a weekend crawling under the car...

I've been emailing an isuzu tech who recommended that I start the car, then climb underneath and disconnect the position sensor, and try to drive it manually to see if it shifts. Disconnecting the position sensor will force it into "true" limp mode, and it should shift manually. If it doesn't shift, then something internal is wrong and the tranny shop needs to fix it. He also sent me the form to send off my PCM to have it reprogrammed if I suspect it's bad.

I'm wondering how the transmission shop verified that the transmission worked? They said "we hooked up to our tester and it shifts through all the gears properly" How exactly do they do that? What is an external tester? A dyno of some sort?
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Old 08-22-2007, 01:35 AM   #12
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Re: 2000 Rodeo Transmission stuck in Limp mode.

The only external test I am aware of is a test drive. It would cost them money to remove and tear open your tranny.

Most chain shops just test drive your vehicle to diagnose a problem. There's a reason most of us don't trust them.
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Old 08-22-2007, 02:44 PM   #13
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Re: 2000 Rodeo Transmission stuck in Limp mode.

They did drive it, they did open it up, and they did 'rebuild' it... I'm not sure what they replaced though...

my question is... they said after they rebuilt it that they tested it 'externally' and that it shifted through the gears.... does this mean that they hooked up power to the solenoids and tested that the solenoids worked? How else would they externally test it?
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Old 08-22-2007, 07:58 PM   #14
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Re: 2000 Rodeo Transmission stuck in Limp mode.

Quote:
Originally Posted by bbohica
They did drive it, they did open it up, and they did 'rebuild' it... I'm not sure what they replaced though...

my question is... they said after they rebuilt it that they tested it 'externally' and that it shifted through the gears.... does this mean that they hooked up power to the solenoids and tested that the solenoids worked? How else would they externally test it?

Are you telling me that they removed your tranny and opened it up to diagnose the problem and then threw an estimate at you? Most shops don't drop the tranny during the "cost estimate" stage. I'm willing to bet all they did was test drive your truck and decided it needed to be rebuilt, UNLESS you saw the removed tranny. Why don't you ask the shop to give you a list of hard/soft parts they replaced and also ask how they tested it? All we're doing is speculating.
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Old 08-22-2007, 10:34 PM   #15
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Re: 2000 Rodeo Transmission stuck in Limp mode.

They drove it.. and supposedly hooked it up to their "trans check" machine, whatever that is.. and said something internal was wrong.. for $350 they would drop it and tear it open to diagnose the real problem... then they said my torque converter was shot and needed replaced, and it contaminated a bunch of stuff when it went out... so... a rebuild was done. They put it back together and now it won't shift... they said it's electrical and not their problem.. and that they did their job, which was to rebuild the tranny...
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