Casper's VSS adapter help needed!

[YGETV8]

I'm new to hybrids having just bought my RX7 3 weeks ago from Ted on here. Got to doing some datalogging and saw that while the Mazda speedo reads just fine, the ECM thinks it is going much slower than it really is. Ted had said the converter lock-up wasn't working, and I'm pretty sure this could explain why! Is there an adjustment that needs to be done? If I mess with it, will I screw up the speedometer reading?

Thanks, Jay

[Orlando_87GN]

You'll need one of these to reduce the speed on the cable for an accurate ECM MPH reading. I don't understand how your speedo in the dash is already accurate, might want to ask Ted how he hooked it up. You'll need to figure out if you have 3.90 or 4.10 gears (was the car auto or manual?) and calculate your tire size to come up with a percentage at which you'll need to slow down the speedo gear with the little gear box.

[YGETV8]

Thanks for the reply, Mike. The center section is an 8.8 with a 3.27 gear. I'm wondering if the correct VSS was used. Casper's shows about three different versions but thier descriptions aren't too detailed. I am sure one is needed to get the correct speedo readout, but in doing so it must be altering the data input into the ECM, too? I might just see about unplugging/bypassing it to see what happens. I can adapt my driving to a speedo that's off, but the ECM can't!

[Electrajim]

I wouldn't unpluug it. The ECM needs to know how fast you are going.
It'll throw a code too.
You may want to ask a chip programmer if they can set things right.
I'd call Caspers first to make sure you have the right sender.

Sounds like a cool hybrid.

ElectraJim

[Budd]

Originally Posted by Electrajim

I wouldn't unpluug it. The ECM needs to know how fast you are going.
It'll throw a code too.
You may want to ask a chip programmer if they can set things right.
I'd call Caspers first to make sure you have the right sender.

Sounds like a cool hybrid.

ElectraJim

I had Eric at TT delete the VSS code in the chip so it won't throw the code 24.

[YGETV8]

Originally Posted by Budd

I had Eric at TT delete the VSS code in the chip so it won't throw the code 24.

That's an idea, but I want TCC and the ECM needs a VSS input to accomplish this, correct?

[Budd]

Originally Posted by YGETV8

That's an idea, but I want TCC and the ECM needs a VSS input to accomplish this, correct?

Didn't think of that. Is TCC locking the convertor? If so, I don't have a lock up convertor in my trans. You could bypass the VSS and use a switch on the shifter to give you a option of locking anytime you wanted for fuel mileage on the highway.

[YGETV8]

That's another option. I don't have an ALDL port... anybody know which ECM pinout(s) I'd need to connect to get TCC? And isn't some of the VSS data used for fuel and timing trims?

[just plain john]

Any progress on this? I have similar questions and could use any help possible.

[YGETV8]

Originally Posted by just plain john

Any progress on this? I have similar questions and could use any help possible.

Haven't gotten to the VSS yet, but just yesterday I wired a 12V ignition source to trans pin "A" and a ground with a console mounted switch to pin "D" (I think it was "D") and now have full manual control over converter lockup. Cost me about $13 in electical parts. Yeah, I have to remember to unlock it when slowing down, but I can live with that!