Limp mode

Hi Henny,

Yuor (and my son's problems) with the limp mode on the '95 Stratus seem to persist. It kepes coming back. Anyone out there with the final solution (aprt from changing the relay's and sensors)?

You should scan for transmission fault codes, which don't show up using the "check engine" lamp method. You really ought to take it in; I wouldn't just cut a wire to keep the tranny from complaining.

The tranny is going into "limp mode" for a reason! Have a reputable shop check out the codes and see what's going on!

"Bruce Yelen" schreef in bericht news: snipped-for-privacy@comcast.com...

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Two official Chrysler dealers checked out the codes by computer. No faults were be found!! I think the tranny is going into limp mode for no reason because the tranny stays fine a long time after a reset. I own the car 2 years and it happens 4 times (in 20.000 km) If the tranny is bad it should happens more often or it had break down after 20.000 km. If there is a wire I can cut to prevent the tranny into limp mode, I cut it and I will see what happen. I will take the risk. When my car is going into limp mode by 120 km/u, it's like you make an emercencystop on the highway for nothing. That's very dangeroes.

>

Just had a thought (yes, I know, what a "novel" idea!) and I'm wondering if it could be the tranny's computer? Had a similar situation on a Buick once. Shop couldn't find any problem with the tranny, etc. Finally they tried putting in a new computer. Problem was resolved.

It sounds like the trans controller is losing power or ground intermittently. Back in 95, everything put the trans in limpin and set a code. 96 and newer software has a completely different limpin strategy (basically 3 strikes and you are out). Carefully check the powers (there are 3) and grounds. Pin 56 is the B+ and should be hot all the time. Pin 11 is an ignition feed and is the wake up signal to the TCM. It is hot in the unlock, run and start positions. Pin 8 is also an ignition feed but is only hot in the start position. When the key is in the start position voltage at pin 8 causes the TCM to go to sleep (no codes and no shift). The NS minivan had a problem with the ignition switch intermittently bleeding voltage into the circuit going to pin 8 causing the TCM to go to sleep while the car was going down the road. This is perceived as limpin, but is not. If voltage is lost at pin 11, the TCM will go to sleep and the result will be a perceived limpin (with no fault codes). Loss of power at pin 56 will cause the same thing. There was enough loss of power issues that DCX instituted a new code (and I can't remember exactly, when 03 or 04 I think) "power up at speed" P0884. The grounds are located at pins 53 and 57.

Bill

Like everyone has been telling you, it is going into limp mode for a reason. I must say I am baffled as to why the dealer was unable to pull any fault codes, but trying to disable limp mode is certainly not the answer. A possibility is that you have a bad connection some place, or it could be more serious.

Could a bad tranny range sensor (the thing that tells the computer what gear you've selected) also act like this? They do go bad occasionally.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

95 and older 41TE's had the PRNDL and Neutral safety switch setup, 93-95 LH's used MVLPS [Manual Valve Lever Position Sensor (a TRS without a temp sensor)]. All 96 and newer (except some early 96 NS's) use the TRS (trans range sensor). If the TCM stops receiving input from the TRS, then the PRNDL display puts a circle around all PRNDL indicators while in park or neutral (as seen by the pressure switches. Code 28 is an indication that the TRS or PRNDL/Neutral safety switch setup has one circuit that doesn't change state or there is no gear indication from the TRS. The first diagnostic step taught to all DCX technicians (trans) is to validate the shifter input. If the TRS doesn't indicate the proper shift lever position, then all fault codes are INVALID. So the long answer to your question is that a bad shifter input can cause all kinds of problems, but usually they set some kind of code even if it's an invalid one that leads you on a wild goose chase. This guy's problem is probably a loss of power. A way to verify this is to hook up a DRB3 just after it happens and read DTC's. If power was lost then the read DTC's screen will show no codes, BUT it will also show a very low "starts since cleared" on the DTC screen. This "starts since cleared" tops out at 255 on most vehicles. So if power wasn't lost, then the number will be high, although disconnecting the battery or the TCM resets this number also. When power is lost the "starts since cleared" is reset to 0. I can't say what any of the other scanners might show.

Hope this isn't too disjointed, Bill "Bill Putney" wrote in message news: snipped-for-privacy@kinez.net...

Not at all. Thanks for the clarification.

Bill Putney (to reply by e-mail, replace the last letter of the alphabet in my address with "x")

"Nomen Nescio" schreef in bericht news: snipped-for-privacy@dizum.com...

No, I have shifted for 32 years. Yes it takes 32 years before I found out how many motions I made before I drove 100 km/u!

1 Pulling down the clutch 2 Shift the first gear 3 Release the brakepedal (Still standing still!) 4 and 5 Press the gaspedal and release the clutch at the same time and yes, the car is moving! It takes 21 motions before I drive 100 km/u in quiet traffic in a 5 speed car. In bussy traffic it is much more. The only thing I have to do in my automatic is release the brakepedal and press the gaspedal! (2 motions in one)

That's why they called it automatic. Very easy when you drive in bussy traffic. Sometimes you don't even hit the gaspedal. .

I think shifting is for boys who think they are tough because they can shift.

Anyway, thanks for your advise but I think you did not understand my question (may be because of my bad english) The question was which wire I have to cut to prevent the tranny of my 95 Stratus in limp mode.

The four times it happend I was driving about 40 mph. It never happends at

120 km/u. I only was afraid it could be happen at 120 km/u. So thank you for your information. When I drive above 45 mph I feel safe now.

"jdoe" schreef in bericht news:TZDYc.85481$Fg5.82641@attbi_s53...

To the contrary. There are 2 kinds of TCM shutdowns (limpin): Orderly shutdown and Immediate shutdown. In an orderly shutdown below 45 mph the TCM just shuts down and the trans immediately goes into 2nd gear. In an orderly shutdown above 45mph, the TCM releases all the clutches (neutral) until speed comes down below 45 mph then the TCM shuts down and the trans is put in 2nd gear. An immediate shutdown occurs when the TCM senses a severe failure that can cause catastrophic trans failure. An immediate shutdown can occur at any speed. Shifting to second gear assumes that the trans is capable of attaining 2nd gear.

Bill

Dude, the computer is the only thing that can shift it. You can't make the computer any happier by cutting wires.

I understand that, but the computer and the tranny are two parts connected by wires. If the computer says "go into limp mode" then this message is send to the tranny trough a wire. Tell me if I am wrong please.

"Joe" schreef in bericht news: snipped-for-privacy@corp.supernews.com...

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"Jan" wrote

It's the other way around: the transmission controller detects an internal problem, goes into limp mode and tells the engine controller about it.

Floyd

I think a lot of you are on to something with the loss of power... neighbor lady had exactly the same problem .. intermittent as can be,, no one could/would take time to fix it... another neighbor and I were discussing it and we came to the same conclusion..however he is the genius not me.. but what he did is hook up a data recorder to the battery, cigarette lighter socket, and the I think the bulkhead connector on the "relay box" under the hood..

What was found was not a total loss of power but,, the voltage normally about 13.6-13.8 or so would drop temporarily (the recorder was digital and couldn't resolve to less than 1 minute) to like 12.5v ,, not enough to really "do" anything but must have been enough to drive the computer nuts.. solution turned out to be the alternator ,, didn't get a chance to disassemble it she had someone else change it,, but it has been over 4 months now with nary a problem, was happening to her about every 2 weeks or so, but really nothing she could put her finger on or cause to recur purposely..

Oh,, her car had about 90000 miles on it at the time..

I think anything would be worth a shot at this point. I suppose if you had a couple voltmeters and a co-pilot you could do the same thing,, dunno for sure.