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can the onboard computers for engine/transmission programmed for mountainous areas?

3.1K views 9 replies 5 participants last post by  IDoMy0wnRacing  
#1 ·
I am moving to WV and have noticed that my 2013 Trailhawk has a lag going up mountains. It has a 3.6 V-6. Is there an update or different setting that will help with this?
 
#2 ·
Typically the PCM recognizes the change and adjusts the air/fuel accordingly. Unfortunately, the V6 is not turbocharged, or, then you'd not even notice altitude at all. I don't really notice any lag with my V8 going up the Rockies, but my friends with the V6's will notice some lag if Jeep is full of people, gear, and/or towing. I can't imagine if just you in your V6 having an issue. If you do, then I'd check the injectors, plugs, etc., and buy a couple cans of BG 44K to clean the fuel system/injectors/etc, as it sounds like something is causing a loss in power. Are you running a very heavy tire like a KO2?
 
#5 ·
The PCM does some minor adjustments to driving conditions over time, so it should auto adjust to some degree. I have a V6 and didn't have any issues visiting my brother in WV. Some folks have said you could disconnect the battery or pull the PCM fuse to accelerate the learning process in a new area, but I've never tried it. I will note that my 2014 had more issues adapting to mountains than my 2018, so I know the programming has been tweaked over the years as well. Night and day difference between the two (but I think my TH has a different rear gear ratio - so it may not be apples to apples).
 
#7 ·
I don’t think the rear axle ratios have changed - they are specific to the engine. The V8 final drive is slightly taller (less rpm’s at a given speed compared to the V6) for fuel economy and the greater available low rpm torque.
 
#8 ·
The transmission adaptives can be reset which will allow the Jeep to relearn for the new driving conditions.
Using AlfaOBD (for example), GEARBOX>Chrysler ZF8HP45> select 'Reset Adaptive Values'.

Any of your local repair facilities with a "Professional" scan tool can reset the transmission adaptives also.
 
#10 · (Edited)
I replaced the 3.09 gears with 3.70 gears in my 2020 GC Trailhawk, 5.7 Hemi. I ordered the differentials for a 2020 GC SRT.

My problem is, when I tell the BCM that I now have 3.70 gears, I get the C2206 - Vehicle Configuration Mismatch error.
Same error message one gets when trying to upsize their tire size in the BCM.

If I run with that (3.70 input in the BCM), it disables the Cruise Control and Forward Collision Mediation.

If I keep it as I am running the 3.09 gears, I get P1DB6 - Vehicle Speed Signal Performance, and P215C - Output Shaft Speed - Wheel Speed Correlation errors. But the Cruise Control and Forward Collision Mediation work.

The speedometer is accurate regardless of gear ratio input, probably because speed is measured by the wheel speed sensors.

I don't know how to defeat the C2206 error message. When I use to work for Dodge, the Service Writer would log onto the Chrysler Website, enter the VIN of the vehicle (Jeep) to update the gearing modification so that Chrysler would recognize that your Jeep now has 3.70 gears. After Chrysler knew that your Jeep, by VIN had 3.70 gears, the Technician could successfully update the BCM. We use to do it all of the time.

I called a few dealer in my area, and NOBODY will even try. NOPE is the easy answer. And I know it can be done...

I am currently running with the BCM set at 3.09 gearing. I have the P1DB6 - Vehicle Speed Signal Performance, and P215C - Output Shaft Speed - Wheel Speed Correlation errors (NO DTCs), and it doesn't seem to affect performance. My Jeep runs great.

Just something to consider when replacing your gear ratios.