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Discussion Starter · #1 ·
Hi All.

I have a JGC Summit diesel 2015 in UK and have been trying to level the front and back with the use of links etc. However, ive noticed that Alfaobd now has the facility to set ride height in mms. Does anybody have details of the factory ride height for this model? Ive researched and been told 97mm front and 83mm rear but this doesnt level the car. Reducing the setting to 60mm on rear doesnt seem to do it either. Any help would be appreciated.

Thanks.
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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I played with the AlfaOBD and was able to adjust my ride height a bit.

I have a 2020 GC Trailhawk that I wanted to lower a little and level it a bit.

At normal ride height, measuring from the ground to the top of the fender, I measured 34 inches up front and 35 inches at the rear. On AlfaOBD, the calibrated height was 90mm front, and 65 rear.
I set the front to 70mm and the rear at 50mm. My normal ride height is now at 33 inches up front, and 33.5 at the rear.

By-The-Way, 50mm is the lowest allowable entry for the rear.

At Exit, it did level it out and drop it a bit.
 

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Discussion Starter · #3 ·
Thanks for reply. So we ignore aero and just measure at normal. My aero ride height was 100 front and 80 rear. Maybe need to get a summit reading for calibrated normal. Not sure if yours is much different?
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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When you guys are changing the front and rear values, do those values apply to all ride height modes? Or can you change each ride height mode individually?
I believe that they do.

I initially measured at normal ride height 34 front and 35 rear and was able to drop it to 33 front and 33.5 rear and my exit height is now at 31.25 front and 32 rear.

After a couple hundred miles my measurements are as follows:
Exit = 31.25 F, 32.00 R
Normal = 32.50 F, 33.50 R
OR1 = 33.63 (33 5/8) F, 34.75 R
OR2 = 34.75, 36.00 R


**all measurements are in inches.
 

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2020 Jeep Grand Cherokee Summit 3.6L 4x2
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Can you change ride heights on each corner or only front and rear??
 

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2013 Jeep Grand Cherokee Trailhawk 5.7L Hemi
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199 Posts
I believe that they do.

I initially measured at normal ride height 34 front and 35 rear and was able to drop it to 33 front and 33.5 rear and my exit height is now at 31.25 front and 32 rear.

After a couple hundred miles my measurements are as follows:
Exit = 31.25 F, 32.00 R
Normal = 32.50 F, 33.50 R
OR1 = 33.63 (33 5/8) F, 34.75 R
OR2 = 34.75, 36.00 R


**all measurements are in inches.
Newbie question here... Will you help me understand the benefits you've gained? It seems you've lowered and leveled your vehicle in all 4 modes and I'm assuming that's for better aerodynamics for NRH, and for more play in the suspension when in OR-I or OR-II which would help eliminate the topping out knocking noise? But do you have good clearance in OR-II for rocks and such? I may be miss-quoting the QL capability here but I thought it can lift 11 inches up. Why did you decide on your numbers and do you forfeit the peak lift height of stock OR-II by doing so? TYIA for sharing your knowledge. I'm doing my best to read through threads and catch up.
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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I sacrificed a little ground clearance by lowering it a bit.

At normal ride height I am now level when connected to my Travel Trailer. Straight line from the back of the trailer to the front of the Grand Cherokee.
I was able to set the squat with the weight distribution hitch, and then fine tuned by lowering the CG's ride height.

Bonus, it looks cool when parked in exit mode. lol
 

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Summit
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So I asked the dev of Alfaodb if this was possible and mainly asking about where you get the ride height numbers, and he pointed me over the Ram Forum and here I found this post

Which has some good info about how this works mainly they have been raising the height but we should be able to lower it
I also hear 50 is the lowest it will go but I have yet to try it on my early 14

I got the alfa because we are supposed to also be able to deflate the systems and fill it back up with Nitrogen, I think my pump is going bad I have been having a lot issues with the ride and feeling like it is soft got a service air suspension once on a really cold morning a few weeks back that got me worried it going.
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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So I asked the dev of Alfaodb if this was possible and mainly asking about where you get the ride height numbers, and he pointed me over the Ram Forum and here I found this post

Which has some good info about how this works mainly they have been raising the height but we should be able to lower it
I also hear 50 is the lowest it will go but I have yet to try it on my early 14

I got the alfa because we are supposed to also be able to deflate the systems and fill it back up with Nitrogen, I think my pump is going bad I have been having a lot issues with the ride and feeling like it is soft got a service air suspension once on a really cold morning a few weeks back that got me worried it going.
It does work for lowering also. anything below 50 for the rear will make the pump keep running in an effort to to lower the Jeep, but won't be able to get there, so-to-speak.

My stock factory setting (2020 Grand Cherokee Trailhawk) were:
Front Left = 90mm
Front Right = 89mm
Rear Left = 65mm
Rear Right - 67mm

I set it to:
Front Left = 75mm
Front Right = 74mm
Rear Left = 50mm
Rear Right - 52mm

gave me a nice look without any errors or issues (all rides levels adjusted and work properly).

You can drain the air ride shocks; the options are Spring Deflate to Atmosphere or Spring Deflate to Reservoir. If yo are going to work on the suspension and save the Nitrogen, Spring Deflate to Reservoir. If you are going to replace contaminated Nitrogen, it is permissible (not against the law) to Deflate to Atmosphere.
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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How I sit right now. I am using AirLinks to lower and AlfaOBD to fine tune and level the ride heights.

Current settings:
Front Left = 80mm
Front Right = 79mm
Rear Left = 60mm
Rear Right - 61m

Park/Exit
230360


Aero
230361


Normal
230362


OffRoad 1
230363


OffRoad 2
230364
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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Anyone have any thoughts on why most of the settings are different from Left to right usually by one or two points? I have noticed this across most of the settings i have seen posted across many post.
I believe that a big part of it is because the leveling rods are different sizes, there are 3 different lengths rods. The two front are the same size and the two rear rods are both different sizes.
Another reason could be that the weight distribution requires an additional millimeter or two of adjustment to achieve a level ride height.
 

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Procharged 2020 Jeep Grand Cherokee Trailhawk, 5.7 Hemi
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I was doing some digging in AlphaOBD today but I don't see where my factory ride heights are listed so I can record them. I want to lower my Summit as well. Where are these listed?
In AlfaOBD

Suspension>
Select Control Unit>
Air Suspension Control Module (ASCM), My>2013 Poweret>
Chose the Battery Icon at the bottom.
Read System Status:
It will look something like this (keep in mind there is a lot more information after what I have listed, but this is what you are looking for (these are my adjusted values (in red, stock values in blue (the stock values were added just for reference))))):

ECU Qualification:
SRT: No
BUX: No
WK/WS: Yes
Bussed Inputs: (RF Hub, PTSnDISP, IC):
Configurable Display Request (Cluster): Default
Configurable Feature Status Request: (Cluster): Default
Odometer: 6011.50 km
RF Functional Request: No Basic REQUEST
Odometer: 6011.50 km
Parktronics System in ON: Yes
Configurable Display Request (Cluster): Default
Configurable Feature Status Request: (Cluster): Default
Load Measurement Requested: No
Assembly Status Register:
Air Mass Estimation Value: 207 Bar-liter
Front Right Sensor Check - Plumbing: Yes
Front Right Sensor Check - Moved: Yes
Front Right Sensor Check - Polarity: Yes
Front Left Sensor Check - Plumbing: Yes
Front Left Sensor Check - Moved: Yes
Front Left Sensor Check - Polarity: Yes
Air Mass Estimation Value: OK
Rear Right Sensor Check - Plumbing: Yes
Rear Right Sensor Check - Moved: Yes
Rear Right Sensor Check - Polarity: Yes
Rear Left Sensor Check - Plumbing: Yes
Rear Left Sensor Check - Moved: Yes
Rear Left Sensor Check - Polarity: Yes
System Fill Time Results: Not started
Height Measurement Stored Status: Complete
Rear Right Measurement Status: Complete
Rear Left Measurement Status: Complete
Front Right Measurement Status: Complete
Front Left Measurement Status: Complete
Move to Normal Ride Height Achieved Status: Complete
AMS Written Status: Not completed
Pressure Vent Valve Test Status: Complete
System Error(s) Present: Yes
OK to Ship: Not completed
Ship Test Status: Not completed
Rolls Test Status: Not completed
Alignment Test Status: Complete
Final Test Status: Complete
Initial Ride Height Test Status: Complete
Fill Test Status: Complete
Suspension Type: Normal
BUX Intrusion Alarm: Not present
Voltages & Direct Inputs:
Battery voltage: 12.30 V
System pressure: 9.20 bar
Pressure Sensor Voltage: 2.22 V
Compressor Temperature: 36 Deg.C
Compressor Temp Sensor Voltage: 1.02 V
Ignition Run/Start: On
RF & LR 5V Supply 1: 5.00 V
Rear Right & Pressure Sensor 5V Supply 2: 4.94 V
LF 5V Supply 3: 4.98 V
Front Left Calibrated Height: 75 mm (90 mm)
Front Right Calibrated Height: 74 mm (89 mm)
Rear Left Calibrated Height: 50 mm (65 mm)
Rear Right Calibrated Height: 52 mm (67 mm)
Level Sensors & Calibration:
Level Calibration Completed: Yes
Front Left Ride Height Sensor: 21.00 mm
Front Left Ride Height Solenoid Duty Cycle: 47 %
Front Right Ride Height Sensor: 22.00 mm
Front Right Ride Height Solenoid Duty Cycle: 45 ...


If you want to save it to your Google Drive, it will be called: ASCM_PN_Info.log
 
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