(12-12-2019, 12:44 PM)fixkick Wrote:(12-12-2019, 11:00 AM)thebanjoman Wrote: With larger tires on a 98 Sport comes an incorrect speedometer. (there is no such speedo for tall tires, at Suzuki.)
My 'attempt' at recalibration, I added a reduction box to the Speedo cable. Now the MPH and Odometer reads very close to perfect.
If this was a Manual trans.. problem solved and done. But it's not.
After adding the reduction box. Now I throw P1875 codes and eventually a check engine light.
Reason is.. VSS in gauge cluster and Speed sensor in 03-72LE 4 Sp Auto differ by more than 10km/h
Per the 1800 supplementary service manual for the P1875 code.
DTC DETECTING CONDITION
While driving at higher than specified vehicle
and with more than specified throttle valve opening,
following conditions are satisfied for specified time.
. Vehicle speed sensed by vehicle speed sensor
speedometer) is more than 10 km/h lower than
sensed by transmission vehicle speed sensor when
4WD low switch is OFF, or
• Vehicle speed sensed by vehicle speed sensor (in
speedometer) is more than 10 km/h higher than that
sensed by transmission vehicle speed sensor when
4WD low switch is ON.
Any way of correcting this and keeping my reduction box in the speedo cable and stop the codes from being thrown? i calculate the difference is now 14-16 km/h
With 40 years of driving under my belt I would like a correct speedo and not have to do mph calcs in my head while driving or have another
external box to show my speed and odometer. I use the odometer for maintenance intervals.
Do I have any options?
THE 1998 sUZUKI sPORT 1.8l j18 ENGINE CAR ,4DOORS, 4WD, RIGHT? JLX SPORT,IS 4DOORS. 4SPEED AT.
ME: I can only guess what this custom car has now..
DIFFERENT 2.3L ECU
The TCM is still separate in all 3 years of SPORT
the TCM needs the VSS sensor at the rear of the AT4 box to read correctly and will not.
the ECU has the speedo, cluster VSS2.
this magic is so if the VSS2 dies, you can drive home and auto shift all 4 grears. if not for that , youd be stuck in 1st gear all the way home or in reverse. (that is what it does)
VSS1 IS PRIMARY , VSS2, IS SECONDARY BACK SPEED SENSOR, AND MUST WORK OR mpg,.. ODOMETER AND VSS2 WILL BE DEAD, OR IN THIS CASE READS SLOW.
THE CABLE MUST BE SPED UP NOT REDUCED BY 10%, TALL TIRES ARE TICKET GETTING TIRES,
AND BOTH SENSOR MUST READ THE SAME.
IS THAT CABLE BOX A CABLE GEAR SPEED UP OR DOWN ? IDK WHAT You have there good day.
Also suzuki changed the meaning of P1875 just for the SPORT, one more odd odd thing that.
It's actually a 2.3, not a 1.8 but in this application it's not relevant. I've put 5000 miles since the swap and love the extra power.
Once again you are 'dead on'. I throw the code because of the difference between 'vss1' and 'vss2' is greater than 10Km/h.
Given the speedo was cable driven the logical approach was to address it at the cable, not understanding that doing this would create another issue.
If the signal from 'vss2' at the trans could be adjusted the same amount that the cable adapter provides perhaps it would stop throwing the code.
It has been suggested to me that maybe a 'yellow box' that is used in electric speedometer applications could be used inline of 'vss2' at the transmission to bring the differences back under the 10km/h and stop the codes. The speedo adjustment made was about 12% so maybe the output at 'vss2' could be adjusted to be 112% to compensate for the change.
It might be an exercise worth trying.