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AW4 - headaches...

LOUD02Special

NAXJA Forum User
So I've been trying to resolve this via searches and reading thread after thread, and I'm getting mixed results at best. Basics - 96 4.0 AW4 231 ~142k

After my last drain and fill of just the tranny pan, the tranny has begun the "I don't want to shift down when coming to a stop" game. It was the 4th drain and fill I've done, to try and slowly and safely change out the fluid in the tranny, since it looked like it had been a long time since it's last flush. I have about 3/4 of a bottle of trans-tune in there from sea-foam, made a small difference, but hasn't solved it yet. I'm thinking about dumping the rest in and doing another drain and fill in a couple days.
Also did the throttle cable adjustment, which gave mixed results. It improved throttle response immensely, but made 1-2 and 2-3 shifts much stiffer at low revs/light throttle. When I'm harder on the gas peddle, the shifts are smoother, like they used to be. Is this a product of the computer and transmission "learning"?
Also, I think I'm just a TAD high on tranny fluid, like barely over the max level. I posed this question in another thread, but want to put it out there again in this thread - can too much fluid play a factor in this? I feel like everything I'm attempting is only making it worse. Ever since I decided I was gonna keep this thing as my DD instead of sell it, it has turned into a massive headache...
 
Ok. AW4 first step: fluid quantity, fluid condition, fluid type. Second step: throttle pressure cable adjustment. Third step: test the TPS. Fourth step: unplug the TCU and see if you get 1st in 1-2; 3rd in 3; 4th in D; reverse, neutral, park. If you get all that driving an shifting manually, then your problem is electronic, not mechanical or hydraulic.

Electronic: TPS, TCU, TCU fuse, solenoids, harness.

AW4 article: http://www.transonline.com/transdigest/magazines/1997-10/Shift Pointers/index.html
 
1st - A bit high on quantity, will be adjusted tomorrow, and it is DexMerc fluid.

2nd - Adjustment - complete

3rd - The voltage at the TPS should be about 5V, yes?

4th - I'll be trying that tomorrow as well and see what happens. Thanks again for all the direction.
 
The 5 volt figure is the reference voltage--that is the voltage supplied by the PCM. It may, or may not, equal 5 volts.

Per 97 FSM (fair use rules):

"THROTTLE POSITION SENSOR (TPS)
To perform a complete test of the TPS (Fig. 37) and
its circuitry, refer to the DRB scan tool and appropri-
ate Powertrain Diagnostics Procedures manual. To
test the TPS only, refer to the following:
The TPS can be tested with a digital voltmeter.
The center terminal of the TPS is the output termi-
nal.
With the ignition key in the ON position, check the
TPS output voltage at the center terminal wire of the
connector. Check this at idle (throttle plate closed)
and at Wide Open Throttle (WOT). At idle, TPS out-
put voltage should be greater than .26 volts but less
than .95 volts. At wide open throttle, TPS output
voltage must be less than 4.49 volts. The output volt-
age should increase gradually as the throttle plate is
slowly opened from idle to WOT."
 
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