Monday, November 27, 2006 - 05:58 pm, by: Andrew Ferres(Peewee)
There are 2 speed sensors on the autobox.
One is a 2 wire, reluctance type, 4 pulse per rev of the tailshaft. Thats the input to the SP2 pin on the ecu.
There is also the speedo sensor. 3 wire hall effect, 4 pulse per rev of the speedo gear. That goes up to the dash (and then from the dash to the ecu as SPD).
You will need to have both of those to stop a speed sensor error.
Now, you cannot reuse the auto's speedo sensor, as its a bolt on, and the W58 will require a screw on one. Plenty of late 80's Toyota's used a 4 pulse per rev screw on speedo sensor. I've actually used an aftermarket one that cost me $110.
Now, I'm not sure if the JZA80 W58's have provision for the 2nd sensor (SP2), but the earlier ones definately don't. What some folks have done is hooked up a sensor on the tailshaft. Works well.
As for the rest of it, I've never played around with manualising a car with a UZZ3x ECU.
I'd hazard a guess that if the ECU can't detect any of the 4 solenoids, it will through a code. Unlikely it will go into limp mode, but you will get some form of error on the dash.
You should be able to use resistors of the right size and rating to trick the ecu into thinking the box is still there.
This brings me to the last possible issue. The neutral start switch. Now its all good and well just bridging it out so the ECU always thinks its in neutral, but if you do that, things like the Cruise Control may not work. What you may have to do is fit a double pole switch on the clutch pedal. Clutch in, neutral switch disabled (car will start) Clutch out, neutral switch enabled (cruise should work)
These are just my thoughts, others may have better input.
Monday, November 27, 2006 - 08:40 pm, by: Mark Paddick(Sparks)
There are actually a total of three speed sensors; Road speed Transmission speed Torque converter speed I'm not sure if the third sensor is needed for the lock-up. If not there the ECU may think the torque converter isn't turning and who knows what that'll make it do. It will have trouble keeping the cruise engaged for starters I think. All three signals can be synthesised from one sensor with a bit of electronic trickery.
Andrew Ferres TryHard WA '86 Cressida V8, '84 Soarer V8, '90 C-F Celsior V8
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