When gasing the engine tranny slips - 1997 Mercury Sable

is it the engine, power dropping
or tranny slipping
this is first. the tachometer tells you which easy.
slips tranny
loss of power , engine.
post which it is ,and if its the engine, do post which one of the many.

what does stops, mean.?> .. skids to stop?
fails hot or cold engine or both? ever to the Full flush service every 50k?
its an A/T and as such , is very complex. (buy M/T?)
are you asking for guessing? or tests?
there are only 2 ways, ask, for DIY or read the FSM.
so what gears fail. slip or shift late or early? lots of gears.
report all actions of all gears and slip for sure.
what is slip?, that is when the RPM of engine rises faster
and MPH lags. called slip or in tranny lingo FLARE !

Did you insert the tranny diagnostic jumper and look for flash codes. per fsm? (on new cars this moved to PCM DTC's)

the FSM has s huge list of symptoms, about 10x and engine.
and 100s of pages.
i dont do A/t rebuilds but i must know how to test them on car.
the FSM covers that.! fully.... no need to guess., at all, read it.

Here i will make some simple review on those first pages
first, we do the stall test. see FSM.
brakes (both) hard set into front wheel chokes, car most not move
dig?
you then (fsm says) slam down the throttle. Low. (and others)
and watch ENGINE RPM
this is like 1500 -2000 (read the book, this number is a avg on cars)
this proves the tranny slips, do so for 5 seconds max.
this makes lots of heat in the tranny , RTM.
the next step is to check actual Tranny pump pressure at the ports
if this fails, the tranny needs to be changed out. (in most cases)

now the TCM. the FSM shows the pins.
The TCM is a tranny puter. (a transmission brain)
it has inputs and the outputs & shifts the tranny in all ways.

we first check that the outputs (a $10 voltmeter) are correct.
if correct and the tranny messes up?, it s a bad tranny
if incorrect we then check the TCM inputs.
if they are wrong, we correct that first.
the rule of GIGO works , for all computers, garbage in , nets garbage out. GIGO, so if the tail sensor is dead the TCM goes to limphome
and skips gears.

easy ,huh> the tranny has many ON CAR test
the above is just but a few, but very important.


alldata.com (fsm like)

also on some cars the OD lamp flashes or the D light? flash
to tell you, THE TRANNY BRAIN, has errors stored, please
do get them and read them, each are very important.
no matter what do the scan (new cars) and all old cars
the TCM diag jumper routine.. do so regardless.. of any trans issues.
never trust any CEL lamp or OD flash, scan it,

does the tranny slip or not.
only you can look and see, got a tachometer or a trained ear?
if it slips and wont go that is tranny issues
if it dont slip and dont go , that be bad engine power.
no one on earth can go from here until that is answered.
job 1.

A/T or M/T (auto or stick ,we dont know)
n moving in drive, reverse or Low or 1? or 2? (me too lazy to look what tranny you have)
it can be 2 things
1: lack of engine power
2: bad clutch or transmission

who do we tell? easy
you step on gas , RPM goes way high and MPH dont. (slips)
tranny slip.
you step on gas, RPM tracks with MPH, good ,
you then do the 5second max. tranny stall test in every car FSM made. and see the stall speed, with brakes hard set.
too high is tranny slip
way to low, engine power POOR.

alldata.com has all this on tranny. stall speed.
the FSM turn to on car A/T service, see STALL test.
bingo.
or youtube the vast number of videos on topic, stall.


wont move at all ,can be :
brake drag (passes stall test)
but first , the tests are, for bad engine or trans,
pick the one it is , state so, and we can go much farther.

Low fluid or too much ATF? (foaming it up and killing bearings)

p07xx is tranny DTC codes. (errors)
TCC lockup failure. (the TCM commanded the lock and
the tail shaft sensor did not rise in RPM
that is the engine RPM does not match tail RPM or 1:1 ratio.
which is LOCK ratio.

1500 is speed sensor , reads wrong,
No Vehicle Speed Signal to TCM.

1624 means.
MIL Request Signal from TCM to ECM.
the means simply the Tcm SAW and error and sent that error up stream to ECM. creating 1500.
remember the ECU never knows what part is bad.
NEVER ! it only knows, the tests failed. (monitors)
the first thing i do is find out which VSS failed.
on some cars there are 2 to 5
the first speed sensor is RPM does the scan tool show correct engine RPM? y/n
if yes,
does the scan-tool show correct MPH? sensor 2.
y/n if not fix that first.
the TCM function (tranny brain must not be lied to, in this order)
engine RPM , MPH.
and last the tranny its self as VSS (rpm) sensors. 1 to3.
my guess, (too lazy to look it up) has 1 sensor on the tranny tail.
if all is good and 1500 means VSS 2 tranny tail is fibbing.
then its one of 3 things.
(all others good)REMEMBER the TCM does comparisons to all speed sensors to shift the car correctly so the front sensor count first. then last the rear.
VSS2 lies. this is bad bad tranny (slips) bad wires to VSS2 or bad VSS2.
most TCM go to limp home when the tranny slips to stop burning up the clutch packs. may skip gears too.

now what does slips out of gear mean. a neutral FLARE?
or down shifts,
if the tranny ever slips. this is bad news.
if it does slip 1500 is only the warning that it did
it say RPMs go out of control and threw 1500 pronto.

Try to think(sic) like a TCM what would you do if the tranny malfs.
answer, throws codes.
and goes to limphome, if necessary, (FSM show these facts)
so does alldata dot com
what i do is try to get tranny to slip. using all gears.
if it slips ,its bad.
The TCM can not run a slipping tranny.
the TC does slip, but the TCM has that all figured out. (modeled)
not locked, and locked it must not.
good luck and do ask questions.

Do you have any check engine codes? If not...you probably do have a slipping tranny.

You can try a tranny additive like trans-medic and see if it helps minimize the slipping.....if not...it may be time to look for a new vehicle.

If you didn't already...you should change tranny oil and filter. This would be a good place to start even if it does not correct the problem. But...before changing tranny oil and filter...with engine running does your tranny dipstick show that tranny has a sufficient amount of oil? If not ...fill to proper level with engine still running and see if that corrects your problem.
Contact: [email protected] for more help if needed...Best wishes!

Previa ECMs CANNOT be 'reflashed". Whoever told you that the SC is programmed to 'choke' is lying to you; there is no such thing. That is the same with the slip, the engine cannot cause the trans to slip. Get another opinion from a credible mechanic. The one you have has no clue.

check your transmission fluid level.if its too low.it will cause tranny to slip.

Unhook the battery for about ten minutes ... that should reset the light... if it comes back on have the codes scanned (autozone is free).

Robert

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