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Shift Solenoid
#1
1997 jlx 1.8l. I have a fault code. P0751. Says the shift solenoid A performance or stuck off. Any experience with this or thoughts? Where is it? From my internet sleuthing found it might be low or dirty transmission fluid or solenoid plugged and dirty.
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#2
the 97 sport with the J18 engine.
sure , the 4 speed A/T is electronically shifted, by a thing called a TCM. shifter brain. (97 is hidden in the ECM now called PCM for this fact)
751s. (with OD flashing?) is trans in limphome mode, skipping 2nd gear?
the transmission auto shifts by solenoids. (electro-hydraulic ) valves, 2 for (the 4 speeds ) an 1 for TCC lockup.
sure levels right and clean is first .
but the TCM , sees solenoid 1 fail. (it activates this solenoid and sees "improper" ratio changes, by measure of VSS tail shift rpm dropping) Slip here is bad news... if it does.
this is caused by the solenoid is bad or the clutch packs slipping.
751 on the 1999 means not stuck but "performance issues", which i think means it slips. SUZ speak for RPM on VSS reads wrong, IMO.
my SOL page..
http://www.fixkick.com/tranny/slush/OD-f...0what.html

the binary code on the connector is shown on my page. called solenoid voltages. a 2 bit binary code. it is.


first after doing level checks etc.
is the stall test, does it pass or fail.? hold brake hard,accelerate in 1st or drive and see RPM ? it must not slip and pass this test.
next is driving, does any gear slip? flogged up hills?
then you can unplug the trans side connector. this puts the transmission in manual mode, (early cars pull tcm connector)
drive, does it shift pre the table of this mode and not slip.
note that 2nd is skipped, in manual mode.

if any gears slips , do the the line pressure tests.

keep in mind the TCM is not smart, it only knows the tail shaft RPM is wrong.
the tech must check for slip and if the TCM is changing to the correct voltages, in call shift points.
if it is ,the solenoids can be removed and replaced if the shift logic is ok (and no slip) but trans fails to reach the correct gear. (via TCM)
one can also check the coil resistance on each solenoid easy , not infinity readings.
they are polarized (diode clamps) the solenoids so do not power them up by hand backwards or they smoke. (burnup)
that is it... on car service.


STALL: test:
the stall test. (3-5 seconds max, rest 5min and repeat if need by..)
ad RPM max. write that down , my G16B car does about 2000 RPM , my H26 V6 is spec'd at 2300- 2600 rpm.
im guessing J18 to be between G16 and H20 stall RPM, or about 2200 RPM?

here is J20 engine, doing stall tests, for MAF, if the maf is good, the 2000 is stall speed.
if the maf is weak you can not get close to 2000. see, the tranny here is used like a Dynometer, loading the engine down.
what you want to do is make sure it dont zoom to 3000 rpm or more... slipping.... bad....
http://www.fixkick.com/videos/FLV-all/showtime.html#MAF
http://www.fixkick.com
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