Cannot shift into 4th or 5th gears

BillTheCat

BillTheCat

New member
My tale of woe.

I have a 2013 JKU with a 3.5" lift and 35” tires. I’ve been running a TrailDash v1 but I decided to ditch it because it was not used much and my front/rear lockers would not work properly via the TrailDash. I reset the ECU first with the TrailDash then with an AEV ProCal. I turned off the “Sway Bar” warning because I have a manual disconnect. Good: Light is out.

Next, I reset the axle ratio to 5.13 (an upgrade about 18 months ago). Next, I set the tire size to 34”. Last, I reset the DTC codes. All is well on the test drive until I stop and start again ... Check Engine light.

My baby cannot get into 4th or 5th gear. First through 3rd is good.

Take the beast to my favorite shop. He hooks up his computer and gets “P0734”. He suggests I go the dealership. Went to setup an appointment to discover my drive warranty is expired in August of this year. Lucky me.
Bought a BAFX Blluetooth OBDII Scan Tool and verified.

****************************************************************
Vehicle VIN:
Vehicle Manufacturer: Chrysler
Vehicle Calibration ID: Not present

Current Fault Log
------------------
ECU reports no current faults

Pending Fault Log
------------------
ECU reports no pending faults

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
P0734: Gear 4 Incorrect Ratio

End of report.
****************************************************************

Capture.JPG

Before I give the dealership all my next upgrade $$$$, I’d thought I’d ask around first.
Thanks!
 
fusion_jeff

fusion_jeff

New member
Sorry to hear you are having issues:

2 things to try before forking over money to the dealership:
1) Reset the ECU back to factory with the AEV ProCal and see if the problem goes away. The flashed override parameters on the ECU may have been corrupted. Flashing back to “Factory” may clear these out.
2) Do a hard reset to clear possible bad adaptive memory parameters:
- Disconnect battery and leave powered down for 8 hours, then reconnect.

Note: A short disconnect only clears temporary volatile memory, not the adaptive memory that could be causing your problem. This adaptive memory is still technically volatile, but is buffered by capacitors similar to having a backup battery. The only real way to clear the adaptive memory any faster is a dealership diagnostic computer triggering a full reset cycle, something a consumer code scanner doesn’t have access to. BTW, disconnecting and shorting your the battery, etc, does nothing but clear temp memory. The capacitors protecting the adaptive memory circuit do not properly drain by shorting out the battery terminals. Any guide you find online saying otherwise was written by an impatient garage mechanic.

If the above works, great you can try re-flashing your AEV ProCal programming back to the vehicle.


Sent from my iPhone using Tapatalk
 
jeeeep

jeeeep

Hooked
BillTheCat said:
My tale of woe.

I have a 2013 JKU with a 3.5" lift and 35” tires. I’ve been running a TrailDash v1 but I decided to ditch it because it was not used much and my front/rear lockers would not work properly via the TrailDash. I reset the ECU first with the TrailDash then with an AEV ProCal. I turned off the “Sway Bar” warning because I have a manual disconnect. Good: Light is out.

Next, I reset the axle ratio to 5.13 (an upgrade about 18 months ago). Next, I set the tire size to 34”. Last, I reset the DTC codes. All is well on the test drive until I stop and start again ... Check Engine light.

My baby cannot get into 4th or 5th gear. First through 3rd is good.

Take the beast to my favorite shop. He hooks up his computer and gets “P0734”. He suggests I go the dealership. Went to setup an appointment to discover my drive warranty is expired in August of this year. Lucky me.
Bought a BAFX Blluetooth OBDII Scan Tool and verified.

****************************************************************
Vehicle VIN:
Vehicle Manufacturer: Chrysler
Vehicle Calibration ID: Not present

Current Fault Log
------------------
ECU reports no current faults

Pending Fault Log
------------------
ECU reports no pending faults

Historic Fault Log
------------------
ECU reports no historic faults
Other discovered fault codes
(possibly pending, current or manufacturer specific)
----------------------------------------------------
P0734: Gear 4 Incorrect Ratio

End of report.
****************************************************************

View attachment 283292

Before I give the dealership all my next upgrade $$$$, I’d thought I’d ask around first.
Thanks!
Click to expand...

How did you measure the tire size?
 
wayoflife

wayoflife

Administrator
Staff member
As mentioned, restore back to stock and then disconnect your battery for 20 min. Try again.
 
jeeeep

jeeeep

Hooked
BillTheCat said:
ACTUAL size: I measured at 32 psi, floor tot he top of the tire.
Click to expand...

this will through it off - measure from the ground to the center of the hub then double it.

that's your actual tire height (rolling height)

set to stock, then re-enter the revised height.

you can use gps speed app to compare what your dash speedometer reads versus what you see on the app.
 
wayoflife

wayoflife

Administrator
Staff member
BillTheCat said:
ACTUAL size: I measured at 32 psi, floor to the top of the tire.
Click to expand...

That would be too high. You need to measure just to the shoulder of the tire - the corner where the sidewall turns to become the tread. OR, you can measure from the center of your wheel to the ground and then x2. That would be ACTUAL size.
 
wayoflife

wayoflife

Administrator
Staff member
jeeeep said:
this will through it off - measure from the ground to the center of the hub then double it.

that's your actual tire height (rolling height)

set to stock, then re-enter the revised height.

you can use gps speed app to compare what your dash speedometer reads versus what you see on the app.
Click to expand...

LOL! Beat me to it and just by a split second. :crazyeyes:
 
BillTheCat

BillTheCat

New member
wayoflife said:
That would be too high. You need to measure just to the shoulder of the tire - the corner where the sidewall turns to become the tread. OR, you can measure from the center of your wheel to the ground and then x2. That would be ACTUAL size.
Click to expand...

Thank you! There is a lot of misinformation out there ...
 
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