Greetings Everyone. 98 GC SE 3.3L 176k. Put 16" wheels on it last year (from 15" OE) and would really like to have the speedo read correctly. Can anyone direct me to a post or thread with instructions on how to recalibrate? Did a search and found it mentioned but no details. Thanks!

 

Has to be done electronically with a scan tool. You have to change the pinion factor in the transmission control module.

 

I'll second that.

 

That's the answer. you need a scanner to reset the pinion factor. No other way.

 

Cougar: I found this on the Durango forum. Does this procedure apply to the Caravan?:

~~~~~~~~~

If the tires are larger than the truck is calibrated for, the speedo would read SLOWER...

See if your cluster is calibrated properly first.

With the key off, hold down the trip/reset button and turn the ignition on. This performs a self test on the cluster where the needles will go to a series of 3 pre-programmed positions. Make sure they all match where they should, use this picture for comparison. This picture is for 97-00 clusters, do not use for 01+ clusters. If you want the pic for 01+, I have it.

 

That procedure checks to see that when the cluster wants to point the pointer at 55, it knows where it is at. And yes, it will work for your cluster. If your pinion factor is off because of the tire change, it won't help that. On the '96 - '00 minivan, the needle pointer is also adjustable with the scan tool so if the pointer isn't pointing at the correct MPH, tach reading, fuel and temp, they can be corrected.

 

Cool. Thanks for your help Tizzy...

 

When the pinion factor is adjusted properly - will that also correct the odometer? My guess is the odometer is also off by 10-15% because I had a drop in MPG right after I put the new wheels on.

 

Hey I'll second that too.

 

Yes, will also correct the odometer.