Quote:
RESERVED:5E77 ldd word_3355
RESERVED:5E7A std word_1436 Speedometer scalar base
RESERVED:5E7D ldd word_3357
RESERVED:5E80 std word_1438 Speedometer scalar - divisor
RESERVED:5E83 ldd word_3359
RESERVED:5E86 std word_143A Stopped vehicle VSS pulse delay
RESERVED:5E89 ldd word_335B
RESERVED:5E8C std word_1434
RESERVED:5E8F ldd word_335F
RESERVED:5E92 std word_15D4
RESERVED:5E95 ldd word_3361
RESERVED:5E98 std word_15D6
RESERVED:5E9B ldd word_3363
RESERVED:5E9E std word_14B6
This is from a 96 lt4 calibration. It might differ slightly in your case. The other config data is also very interesting but nobody knows what it does.
Quote:
This is the base scalar for speedometer calibration. This should be set to PPM/4000.
You may develop a PPM value as follows:
PPM = sensor spec * gear ratio * tire revolutions per mile
known sensor values:
- 40 for a 4L60E
- 17 for a T56 F-body or B-body
- 2 for a T56 Y-Body
_______________
This is the divisor for speedometer calibration. This should be set to, after the base scalar is determined, to:
4000 / ( PPM / Speedometer Scaler - Base )
You may develop a PPM value as follows:
PPM = sensor spec * gear ratio * tire revolutions per mile
known sensor values:
- 40 for a 4L60E
- 17 for a T56 F-body or B-body
- 2 for a T56 Y-Body
_____________________________
When a VSS pulse has not happened for this amount of time, the vehicle is considered 'stopped'.
70-80msec seems to be appropriate.
Quote:
On the output side, I have been told that the pulse rate is 4000/mile. Is this true of all the options? I know mine had a 250 KPH speedo. Others had tires that limited the top speed to some lesser number and I believe the gauge was calibrated for a lower top end. Is this calibration taken up in the dash it's self?
The vss output is used for all the modules in the car, dash, abs, sir, radio, cruise control. It is fixed value of 4000ppm. The input and conversion is what differs.