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Discussion Starter #1 (Edited)
My 2014 3.2 4x4 vibrates on hard acceleration. I checked all the CV shafts and the driver rear shaft could be wiggled around a little bit by hand, so I assumed this was the issue, shaft was replaced. The vibration is still there, and actually, pretty sure it is worse after the shaft replacement. This is the shaft that comes out of the driver's side of the RDM (Rear Drive Module), and I can still wiggle that shaft around a little by hand, same as before the shaft was replaced.

And, they broke the wheel sped sensor when replacing the CV shaft, and it had to be replaced.

I thought the vibration had something to do with the PTU rerouting power to the rear wheels, since it only happens on hard acceleration, so I removed the PTU fuse to test, no change. Then I thought is must be coming from the RDM output shaft, since it has a little play, in another thread though, someone said they have play in theirs too, and Andre said he still has a very small amount even after replacing the RDM and CV shaft.

I have now noticed, if I turn off ESC with the button, the vibration is completely gone, so I looked up what happens when you push that button, or put it in a driving mode that disables it, like Sport. It's way more complicated than I thought, did you know this thing will apply the brake to one ore more of your wheels if it thinks your vehicle is not following the line it thinks it should based on how much you are turning the steering wheel and the rotation of your tires? You are not touching the brake pedal. That's crazy, lol.

There are 3 main components to ESC, BLD (Brake Lock Differential) which uses the brakes to make both rear wheels turn at the same speed, this can be ruled out as the cause, as it is NOT disabled when you turn off ESC, then brakes, and engine tourque. The engine tourque component just reduces engine tourque if you are driving like a maniac, to try and maintain control, so I can't see that being the cause either. The brake portion will actively apply braking in any oversteer/understeer situation.

Anyway there is a lot going on there, and the vibration is gone when ESC is turned off, so I think, my hypothesis is, that the wheel speed sensor has been replaced on the driver's side, but the passenger side still has the original, and that is somehow causing a mismatched wheel speed in the computer, and it is compensating by pulsating the break because it thinks the car is in an oversteer situation due to the mismached wheel speed from the sensors(it thinks vehicle is turning more than appropriate for the steering wheel position). Or maybe the wheel speed sensor on the passenger side is going bad.

I guess it could also be a bad steering angle sensor, but I am leaning away from the looseness in the output shaft of the RDM as a cause, since the vibration completely goes away when I push that ESC button.

Do you guys know of any testing I can do short of removing the wheel speed sensor and cleaning it? I am afraid if I try to remove it, it will break. I also read the "ring" the sensor sees can get dirty and cause misreadings as well.
Thanks!
 

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My 2014 3.2 4x4 vibrates on hard acceleration. I checked all the CV shafts and the driver rear shaft could be wiggled around a little bit by hand, so I assumed this was the issue, shaft was replaced. The vibration is still there, and actually, pretty sure it is worse after the shaft replacement. This is the shaft that comes out of the driver's side of the RDM (Rear Drive Module), and I can still wiggle that shaft around a little by hand, same as before the shaft was replaced.

And, they broke the wheel sped sensor when replacing the CV shaft, and it had to be replaced.

I thought the vibration had something to do with the PTU rerouting power to the rear wheels, since it only happens on hard acceleration, so I removed the PTU fuse to test, no change. Then I thought is must be coming from the RDM output shaft, since it has a little play, in another thread though, someone said they have play in theirs too, and Andre said he still has a very small amount even after replacing the RDM and CV shaft.

I have now noticed, if I turn off ESC with the button, the vibration is completely gone, so I looked up what happens when you push that button, or put it in a driving mode that disables it, like Sport. It's way more complicated than I thought, did you know this thing will apply the brake to one ore more of your wheels if it thinks your vehicle is not following the line it thinks it should based on how much you are turning the steering wheel and the rotation of your tires? You are not touching the brake pedal. That's crazy, lol.

There are 3 main components to ESC, BLD (Brake Lock Differential) which uses the brakes to make both rear wheels turn at the same speed, this can be ruled out as the cause, as it is NOT disabled when you turn off ESC, then brakes, and engine tourque. The engine tourque component just reduces engine tourque if you are driving like a maniac, to try and maintain control, so I can't see that being the cause either. The brake portion will actively apply braking in any oversteer/understeer situation.

Anyway there is a lot going on there, and the vibration is gone when ESC is turned off, so I think, my hypothesis is, that the wheel speed sensor has been replaced on the driver's side, but the passenger side still has the original, and that is somehow causing a mismatched wheel speed in the computer, and it is compensating by pulsating the break because it thinks the car is in an oversteer situation due to the mismached wheel speed from the sensors(it thinks vehicle is turning more than appropriate for the steering wheel position). Or maybe the wheel speed sensor on the passenger side is going bad.

I guess it could also be a bad steering angle sensor, but I am leaning away from the looseness in the output shaft of the RDM as a cause, since the vibration completely goes away when I push that ESC button.

Do you guys know of any testing I can do short of removing the wheel speed sensor and cleaning it? I am afraid if I try to remove it, it will break. I also read the "ring" the sensor sees can get dirty and cause misreadings as well.
Thanks!
Interesting information. I can tell you that it sure doesn't seem to help the torque steer much on my turbo. Especially when I am accelerating hard while turning the torque steer can be pretty bad.
 

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following your logic it would be the passenger side sensor going bad, as you had the problem before the other one was changed out....
 

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Tyler, can Alpha monitor HCU functions? There are 2 TC valves, normally open that would be suspect.
 

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On that screen what's listed is what you get, on the graph screen you are only limited by what can be displayed on the screen (but you can still scroll) so if the value is listed it can be displayed.



I'll post some of the values this weekend when i'm off work and I get a chance to work on my 2014.
 

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My 2014 3.2 4x4 vibrates on hard acceleration. I checked all the CV shafts and the driver rear shaft could be wiggled around a little bit by hand, so I assumed this was the issue, shaft was replaced. The vibration is still there, and actually, pretty sure it is worse after the shaft replacement. This is the shaft that comes out of the driver's side of the RDM (Rear Drive Module), and I can still wiggle that shaft around a little by hand, same as before the shaft was replaced.

And, they broke the wheel sped sensor when replacing the CV shaft, and it had to be replaced.

I thought the vibration had something to do with the PTU rerouting power to the rear wheels, since it only happens on hard acceleration, so I removed the PTU fuse to test, no change. Then I thought is must be coming from the RDM output shaft, since it has a little play, in another thread though, someone said they have play in theirs too, and Andre said he still has a very small amount even after replacing the RDM and CV shaft.

I have now noticed, if I turn off ESC with the button, the vibration is completely gone, so I looked up what happens when you push that button, or put it in a driving mode that disables it, like Sport. It's way more complicated than I thought, did you know this thing will apply the brake to one ore more of your wheels if it thinks your vehicle is not following the line it thinks it should based on how much you are turning the steering wheel and the rotation of your tires? You are not touching the brake pedal. That's crazy, lol.

There are 3 main components to ESC, BLD (Brake Lock Differential) which uses the brakes to make both rear wheels turn at the same speed, this can be ruled out as the cause, as it is NOT disabled when you turn off ESC, then brakes, and engine tourque. The engine tourque component just reduces engine tourque if you are driving like a maniac, to try and maintain control, so I can't see that being the cause either. The brake portion will actively apply braking in any oversteer/understeer situation.

Anyway there is a lot going on there, and the vibration is gone when ESC is turned off, so I think, my hypothesis is, that the wheel speed sensor has been replaced on the driver's side, but the passenger side still has the original, and that is somehow causing a mismatched wheel speed in the computer, and it is compensating by pulsating the break because it thinks the car is in an oversteer situation due to the mismached wheel speed from the sensors(it thinks vehicle is turning more than appropriate for the steering wheel position). Or maybe the wheel speed sensor on the passenger side is going bad.

I guess it could also be a bad steering angle sensor, but I am leaning away from the looseness in the output shaft of the RDM as a cause, since the vibration completely goes away when I push that ESC button.

Do you guys know of any testing I can do short of removing the wheel speed sensor and cleaning it? I am afraid if I try to remove it, it will break. I also read the "ring" the sensor sees can get dirty and cause misreadings as well.
Thanks!
 

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Bud I think it might be your Steering Sensor that needs re-calibration especially if the battery was unhooked or repairs done it has a way of not sending the right info to the ESC if it like wobbles turning from a stop when you accelerate or wobbles on an agessive acceleration going forward DO THIS get on gravel start you jeep press you ECS button OFF (so the yellow warning shows the little truck with the skids in the dash) in park slowly turn the steering all the way right then slowly turn the steering all the way left then slowly turn the steering to center again then turn your ESC back ON (so the dash light goes off) shut the jeep off for a while 5-10 min start er up take her for a test drive LET ME KNOW lol lol It sounds weird but its the way to recalibrate your steering sensor so the ESC gets the proper info
 

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Bud I think it might be your Steering Sensor that needs re-calibration especially if the battery was unhooked or repairs done it has a way of not sending the right info to the ESC if it like wobbles turning from a stop when you accelerate or wobbles with agressive acceleration in low gears going forward. DO THIS get on gravel start you jeep press you ECS button OFF (so the yellow warning shows the little truck with the skids in the dash) in park slowly turn the steering all the way right then slowly turn the steering all the way left then slowly turn the steering to center again then turn youe ESC back ON (so the dash light goes off) shut the jeep off for a while 5-10 min start er up take her for a test drive LET ME KNOW lol it sounds weird but think abot it and give it a shot it recalibrates the steering sensor and the ECS gets the correct info to react.GOOD LUCK
 

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Sorry every time I try to edit Its creating another post great start for me HERE LOL LOL Maybe if its the FIX I shall be redemeed lol
 
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