I used the AEV Pro Cal to calibrate my speedometer and auto transmission shift points several months ago and it has worked perfectly so far. However, today I ran into a problem. I brought my Jeep to the dealership for routine maintenance and for a recall, so I restored my vehicle to stock as a precaution to avoid having my warranty flagged, and the horn sounded three times. I drove it home stock, and as expected the speedometer and the shift points were off.

When I got home, I used the pro cal to reset my computer and the speedometer stopped working. I can tell the shift points are properly reset, but I can't figure out why the speedometer won't work. If I restore the computer to stock, then the speedometer works, but it is not calibrated. Has anybody else had this problem? Any help would be appreciated.

 

sorry, cant help, but this is 3 weird procal issues this week on this board. mine wouldnt do extended idle until i unplugged and plugged it in about 10 times.

good luck.

 

man that sucks I have never had this problem before. I have returned mine to stock severL times and Everytime I recalibrate it works just fine. That's weird. Please post if u can fix the problem!

 

Redo it and only pull the pro-cal out after you turn the ignition off and take the key out.

Ex. Horn beeps, turn off ignition, take out key, remove procal from port.

 

Tried it again exactly as you instructed; same result. I also disconnected the battery for 10 minutes and repeated the steps with the same result.

I also noticed something else: In addition to the speedometer not working, the change oil message also appears, which is strange. Ugh, time to contact AEV.

 

The issue has been resolved. Insted of trying to explain it myself, I'll just copy and paste the email I got back from AEV:

Any time the Procal is used, the key MUST be cycled to OFF before the engine is started. If this is not done on the Tire Size programming (or restoring) the car can become in conflict about what the agreed upon tire size is. If the car is in conflict it will shut the speedometer down and set a check engine light. Take a look at this forum link below, it contains a full overview of the problem and five solutions to the issue.

http://forum.aev-conversions.com/showthread.php?t=684

For you I recommend, turn the vehicle to ignition (one key click just before START), setting a new tire size value that is .25" different from your correct value, wait for the honk, turn the key off, then repeat but use the correct tire size, then turn the vehicle off. This will fix your speedometer issue (and Sway bar if that light is on). The Check Engine light may still be on. If it is, you can either Wait for it to go out, use the Procal to "Clear DTCs" (it's under Engine Functions), or you can put the Positive cable on the battery for 10-20 minutes.

One last note. The Procal is 100% DEALER SAFE. There is absolutely no need to restore the procal before going to the dealer. The dealer can not void your Warranty for anything the Procal does. The restore feature should ONLY be used if you plan on putting the vehicle back to stock and selling it, then using the procal in another vehicle.

Oh, and Change Oil is probably just coincidental or happened because of the battery reset. To get rid of that, Turn the key to ignition, and press the gas pedal three times then start the car. It may be press the gas pedal three times then turn it off (instead of start). Give that a try.


...so mkjeep was right, I just had to do that one extra step to clear it I guess. Thanks to AEV for getting back to me. Hopefully somebody finds this info useful.

 

Thank you for following back up with AEV's response.

I did the exact same thing (restored to stock before dealer visit) when I did my horn honked three times. The dealer called me to let me know my check engine light was on, something about the computer being confused about tire size and gear ratio.

When I get my Jeep back I will have to try this.

Thanks again!

 

Thanks for posting AEV's response. I was just reading out of curiosity, but came across the "oil change" information. Thanks - I was trying to figure out how to get rid of that!

 

One thing I noticed with my Jeep is to do the gear ratio first and then the tire size. I have a manual so I don't know what the ECU is doing with gear ratio info other than for the speedometer along with the tire size.