Limp mode

Hello,

Is there an "electronical wizzard" out there who can tell me which wire a
have to cut to prevent the tranny of mine 95 Stratus goes in limp mode?
I have replace the ATF3 + filter, the in- and out sensors and the TCM
relais. I don't get any faultcodes (only 55 which means "end faultcodes"). I
don't believe the seals are bad because when the tranny goes in limp mode
and I reset it (turn off the engine and start again) it stays fine for
another 1000 miles.

Thanks for your suggestions.

 

IT's going into limp mode to protect itself from further damage. Get the
TRANS codes scanned and than see what they entail. DO NOT go cutting wires.
Larry

 

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!

 

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

 

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")

 

If your car is going into limp at 120 kph (62 mph (I think) you've got
something VERY weird going on. THe proper computer is rigged to NOT allow
limp mode to occur above 45 mph (whatever that is for you KPH folks). I'd
find another dealer. I bet you've got anold computer on this rig.
Larry

 

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.

 

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.

 

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

 

No, obviously you *don't* understand that. If you *did* understand that,
there would be no "but" at the end of your sentence. Your transmission
will have one gear only (2nd) if the computer and transmission cannot see
each other. Your transmission is going into limp mode because there is
something wrong with it. Fix it!

 

I kind of know how dangerous limp mode can be on the highway. I used to own
a '95 Chrsyler Cirrus, was the worst car I ever owned in my life... bought
it when it had 40K miles. I bought an extended warranty, within the first 2
months of ownership, throttle position sensor failed... got replaced under
warranty, then shortly the following month my transmission failed. That too
got replaced by warranty.... then all went downhill. Warranty expired, had 3
more transmission failures, a/c went, ABS controller failed, and
transmission computer failed and had to get replaced... was so tired of
getting it fixed.. finally gave the car back to the bank...couldn't afford
fixing it and paying the loan at the same time. All this and the car had
only 87K miles when i gave it up.