F45 Delete question
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Navigator
Joined: Apr 2012
Posts: 9
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F45 Delete question
Ok,
Replaced the shocks with Z06 shocks, installed my own simulators, no dtc's active or stored.
I did find that the ride height was off in the front my quite a margin and have since lowered it, allowed it settle. During my drives here and there to work in the front ride height the TCS intervenes every time around 45 mph and any amount of turning.
So my question is that is the system doing this because the front to rear "rake" is off. Note that I haven't adjusted the rear to match the front yet as I wanted the front to settle.
No dtc's just have the throttle taken away and have to hit the TCS off button to resume driving.
I of course plan to lower the rear to match the front but want to know if this will continue.
I have NOT yet put the Z06 sway bars on the car yet. I did notice that the car lacks turn in and wiggles in the *** more than I care and figure the softer F45 bars are likely the cause.
Just making sure I'm thinking this threw. I'm not a GM tech but was for Chrysler Dodge Jeep for 15+ years. So I know how to spin a wrench.
These electronics simply work different than what I'm used to. Viper doesn't use ride height sensors for this type of "input."
Replaced the shocks with Z06 shocks, installed my own simulators, no dtc's active or stored.
I did find that the ride height was off in the front my quite a margin and have since lowered it, allowed it settle. During my drives here and there to work in the front ride height the TCS intervenes every time around 45 mph and any amount of turning.
So my question is that is the system doing this because the front to rear "rake" is off. Note that I haven't adjusted the rear to match the front yet as I wanted the front to settle.
No dtc's just have the throttle taken away and have to hit the TCS off button to resume driving.
I of course plan to lower the rear to match the front but want to know if this will continue.
I have NOT yet put the Z06 sway bars on the car yet. I did notice that the car lacks turn in and wiggles in the *** more than I care and figure the softer F45 bars are likely the cause.
Just making sure I'm thinking this threw. I'm not a GM tech but was for Chrysler Dodge Jeep for 15+ years. So I know how to spin a wrench.
These electronics simply work different than what I'm used to. Viper doesn't use ride height sensors for this type of "input."
Thread Starter
Navigator
Joined: Apr 2012
Posts: 9
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Yeah I figured the same. That's why I was curious to know if the ride height sensors are considered an "input" to the TCS System.
We don't have them on Viper. Viper uses only the "g" sensor along with wheel speed, steering angle,etc to determine car attitude.
IF the ride height is part of the "issue" that would be sorted out shortly after I put the Z06 bars and adjust the rear height to match the front.
We don't have them on Viper. Viper uses only the "g" sensor along with wheel speed, steering angle,etc to determine car attitude.
IF the ride height is part of the "issue" that would be sorted out shortly after I put the Z06 bars and adjust the rear height to match the front.
Racer
Joined: Feb 2004
Posts: 359
Likes: 7
From: St. Paul MN
The symptom you describe of TCS engaging randomly sounds like a failing steering wheel position sensor. Others threads here have described similar fault.
The C5's have a stock rake height difference front to rear. The service manual has several measurements and procedures to determine Z and D height for front and rear stock values. If you don't have the manual, it's a valuable tool.
Regarding the ride height being considered in the stability control logic, it is not identified in the service manuals related to TCS. Cars without F45 RTD will not have these height sensors, so I suspect it is not a factor (and certainly not required). Ride height would have to be constantly transmitted over the OBD2 bus by the RTD, and I don't recall seeing it in my sniffing.
The description of the ride height sensors in RTD make no mention of height being used externally by TCS.
Originally Posted by Randy P
IF the ride height is part of the "issue" that would be sorted out shortly after I put the Z06 bars and adjust the rear height to match the front.
Regarding the ride height being considered in the stability control logic, it is not identified in the service manuals related to TCS. Cars without F45 RTD will not have these height sensors, so I suspect it is not a factor (and certainly not required). Ride height would have to be constantly transmitted over the OBD2 bus by the RTD, and I don't recall seeing it in my sniffing.
The vehicle stability enhancement system (VSES) includes an additional level of vehicle control to the EBCM. The VSES is activated by the EBCM calculating the desired yaw rate and comparing it to the actual yaw rate input. The desired yaw rate is calculated from measured steering wheel position, vehicle speed, and lateral acceleration. The difference between the desired yaw rate and actual yaw rate is the yaw rate error, which is a measurement of oversteer or understeer. If the yaw rate error becomes too large, the EBCM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.
The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the driver's steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.
The amount of differential braking applied to the left or right front wheel is based on both the yaw rate error and side slip rate error. The side slip rate error is a function of the lateral acceleration minus the product of the yaw rate and vehicle speed. The yaw rate error and side slip rate error are combined to produce the total delta velocity error. When the delta velocity error becomes too large and the VSES system activates, the driver's steering inputs combined with the differential braking will attempt to bring the delta velocity error toward zero.
The ESC controls the damping mode selection according to the following factors:
The vehicle speed
The chassis pitch input
The steering position
The body to wheel displacement
The ride control switch position
The ESC module evaluates these inputs in order to separately control the solenoid valve position in each of the shock absorbers, providing an enhanced ride and comfort level over the widest possible range of operating conditions.
....
The position sensors provide the ESC module with the body to wheel displacement input. The ESC module uses this and other inputs in order to control the position of the shock absorber solenoids. If any body or wheel motion is detected, the ESC module will determine how soft or firm each shock absorber should be to provide the best ride. The position sensors are mounted at each corner of the vehicle between the control arm and the body.
The vehicle speed
The chassis pitch input
The steering position
The body to wheel displacement
The ride control switch position
The ESC module evaluates these inputs in order to separately control the solenoid valve position in each of the shock absorbers, providing an enhanced ride and comfort level over the widest possible range of operating conditions.
....
The position sensors provide the ESC module with the body to wheel displacement input. The ESC module uses this and other inputs in order to control the position of the shock absorber solenoids. If any body or wheel motion is detected, the ESC module will determine how soft or firm each shock absorber should be to provide the best ride. The position sensors are mounted at each corner of the vehicle between the control arm and the body.
