85LSburb

iTrader: (1)

I am having problems with my vss. I have a Dakota digital 8k pass threw pulse generator. It has two wires and the vss plug coming from engine harness also has two wires. I hooked the wires up and my ECM is only seeing 4 mph when my mechanical speedo says 65. Any ideas?

71403

Was the PCM tuned to the PPR of the pass thru VSS?

85LSburb

iTrader: (1)

I told them to set it to 8k. I have no way to find out for sure.

garys 68

iTrader: (1)

The standard VSS puts out 17 - 40 pulses per rev. As you figured out, the DD putss out significantly less. Some tuning software can adjust that low (Brendan at LT1swap was able to correct mine).
If you want it corrected so that DBW cruise control will work, dont bother. The pulse rate is too low for a stable signal. If you want it corrected so that you wont have stalling problems, it doesn't have to be accurate.

85LSburb

iTrader: (1)

I just want it to work to fix my stalling issues. It says it puts out 8000 a mile. Any one use anything else on a old 700r4?

garys 68

iTrader: (1)

On both of my LSx manual trans swaps, the unadjusted VSS signal was adequate to eliminate the stalling.
Are you still having stalling with it as is?

85LSburb

iTrader: (1)

Yes stalls alot. Not so bad if i get over 15 mph then slow down. But backing up or moving slow it stalls almost everytime. Ecm does not see speed tell i get over 15 mph and the ecm sees 1 mph.

71403

Sure sounds like the PCM calibration is wrong.

85LSburb

iTrader: (1)

I hope so. On a side note can a tuner do a crank relearn? I have a that code active.

JMac11

Did you find a work around or is cruise not compatible with the DD VSS?

garys 68

iTrader: (1)

The DD pulse rate is too low for a stable signal. When CC was engaged the car would either run wide open or zero throttle. Btw, that was a bit of a shock the first time. I confirmed the ecu was generally reading close to correct speed, but at high sample rate, it would read high or low by about 20mph. Not sure if there are any bandaid fixes. I ended up running an aftermarket VSS off the T10 trans 39 tooth reverse gear.