vss problems on 730..again

[Shannen Durphey]

Hi, Mike.

Found this letter just tonight.  I thopught it might be of relevance.
Shannen

> Subject: 
>           7730 Vss signal processing
>      Date: 
>           Mon, 07 May 2001 22:18:45 -0500
>      From: 
>           "K.E.T." <karljiml at compuserve.com>
>  Reply-To: 
>           gmecm at diy-efi.org
>        To: 
>           gmecm at diy-efi.org
> 
> 
> 
> 
> I think I've learned that the 7730 ECM, depending on the car in which it is 
> installed, handles the Vss signal two ways:
> 
> A) Raw Vss signal from transmission sensor input on pins B9 & B10, and 
> outputs signals for 4000p/mi on pin B11and a 2000 p/mi  on pin C1
>    OR
> B) Accepts a 4000 p/mi signal from an external signal buffer (yellow box) 
> on pin C6
> 
>  From experience, if the MEMCAL is expecting option B, but the car is wired 
> for option A, a digital speedometer reads much higher than actual speed.
> 
<snipped>

> Karl


Mike Rolica wrote:
> 
>     Sorry i have been away for a while..
> rx7 or rx8 is now safteyed and on the road..
> got a problem with the vss..
> the mazda vss. is twice the speed of what the ecm wants.
> ie ecm thinks 50mph is 100mph. This causes some problems with tcc ect.
> I am running aujp code in a 730, but while it was in my truck i had it setup for the optical sensor...
> anyone got any ideas on how to make this accurate ?
> 
>   -----------------------------------------------------------------------------------
> 
>                   Name: FILE.HTM
>    FILE.HTM       Type: Hypertext Markup Language (text/html)
>               Encoding: 7bit
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org