"Service Ride Control" ????? What does this mean!?

Discussion in 'Chevy Tahoe Forum (GMC Yukon, Cadillac Escalade)' started by Kady, Aug 18, 2012.

  1. Kady

    Kady Epic Member 5+ Years GMTC Chick 100 Posts

    Getting in the truck after going out to eat, "service ride control" came on.. I hooked the scanner up, and nothing came up... What does this typically mean? If it has something to do with the "air ride system," my compressor kicked on fine when I pulled back up to my house while I was getting out the scanner... Any ideas? If its not one propblem its another.
  2. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    Having an older Tahoe I personally don't know much about the air ride system but my best guess would be the system might be sensing lower pressures than normal or the system not being efficient enough. Since your Tahoe is 12 years old that's just a lot of wear and tear on any system if I were you I'd ignore it until the next time you have the dealer service your vehicle then mention it to them, that is if you don't feel that something is abnormal with your truck.
  3. the phantom

    the phantom Epic Member 5+ Years ROTM Winner 1000 Posts

    Ive had this come up on my 03 Escalade. I ignored it until finally the air compressor didnt work anymore. If your hearing your air compressor come on without putting a load into the vehicle then your shocks probably have seals going bad. This was the case with my caddy. It eventually got worse to the point that the compressor burned itself out trying to keep the air in the shocks that couldnt hold air anymore. There are replacement shocks to eliminate this type of system because the air ride shocks are expensive. If you want to retain the system I would look at the shocks first before it gets worse and your air compressor burns itself out like mine. I drive my caddy with the same shocks in it yet and it still rides decent. But Im looking at about $700 for the shocks and replacement air compressor to fix. Hope this isnt whats going on with yours but mine was only 8 years old and 70,000ish miles when it happened. Good Luck!!
  4. Kady

    Kady Epic Member 5+ Years GMTC Chick 100 Posts

    Yeah, my truck's 12 years old, I don't bring it to the dealer.
  5. Kady

    Kady Epic Member 5+ Years GMTC Chick 100 Posts

    I'm gonna take a look at it tomorrow, I'd prefer to just eliminate it... I was looking to upgrading the suspension because i pull a catering trailer once a while. I have the dually for towing, but once in a while have to use the Tahoe, and the truck squats like crazy with the trailer.
  6. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    Well if you want a good low maintenance ride control system I have a link for it just need to find it...:neutral:
  7. the phantom

    the phantom Epic Member 5+ Years ROTM Winner 1000 Posts

    If it will work on my caddy I may be interested.
  8. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

    There's the link learned about it when I was asking how to help my Tahoe from sagging so bad the trucks rear currently sits 3 inches from factory height. I'll send the link to the thread it is from.
    Here's a link to another air shock system i found it seems nice but haven't seen any reviews.
    You might need to look at the catalog for your year that's from my year.
  9. Conlan Rose

    Conlan Rose Epic Member 5+ Years 1000 Posts

  10. BillD64

    BillD64 Rockstar

    As others have said it could be leaks in the shocks, a problem with a wheel position sensor or an issue with the compressor. The message was caused by a diagnostic code that was generated by the Ride Control Computer. The problem is you can't read that code with an OBD II scanner. You need one that can read body codes and they are expensive and brand specific. The ride control system controls both the shock valving at the front and rear of the vehicle plus the ride height at the rear of the truck. If you lose pressure in the air ride portion of the system (line or shock blows out the compressor will stop running after 5 minutes if the Ride Control Computer doesn't detect a change in the height of the vehicle. If a wheel position sensor has an issue the shock valving will not work and if the sensor is in the rear the air shocks may not operate either since the computer needs to know how high or low the vehicle is. You really need to know the code that is causing the message so you can look in the correct area. The code can also be caused by a bad Ride Control Module or the wiring going to it and any of the other parts of the system.

    Here is some info from the Service Manual:
    "Real Time Damping Description and Operation
    The RTD system is bi-state real time damping, two corner rear leveling (if equipped), and a electronic variable orifice, (EVO) power steering system, (if equipped).

    The RTD system consists of the following:
    • Suspension Control Module
    • Compressor/Leveling Module
    - Pressure Sensor
    - Exhaust Solenoid
    • Compressor Motor Relay
    • Steering Wheel Speed/Position Sensor
    • Electronic Variable Orifice (EVO) Solenoid
    • Shock Solenoid Valves
    • Position Sensors

    The objective of the suspension control module is to provide ride and handling results that are superior to a passive damper system, both on and off road at all load conditions. The suspension control module monitors body-to-wheel height, vehicle speed, handwheel position/speed, lift/dive status and a driver tow/haul input switch status in real time and instantly selects a "normal" or "firm" mode. This is done for each of the front and rear shock absorbers in order to adjust the vehicle for specific road and driving conditions.

    The suspension control module will use the rear body-to-wheel displacements and vehicle speed inputs to keep the rear trim height of the vehicle at its desired level. This is done to optimize suspension geometry, headlight aiming, ride travel and keep the vehicle visually level. The system utilizes the compressor motor relay and the compressor/leveling module which contains the exhaust solenoid, pressure sensor and compressor motor. The vehicles's rear leveling compressor motor is switched ON and OFF via a compressor motor relay which is controlled by the suspension control module. The suspension control module provides a switched path to ground whenever compressor activity is required. The suspension control module supplies 5 volts to the RTD air pressure sensor. The pressure sensor uses this reference voltage to produce an analog output of approximately 0.15 to 4.85 volts. The signal voltage is a reference of the air pressure in the rear leveling system. The exhaust solenoid valve is switched ON and OFF via the suspension control module. The suspension control module provides a switched path to ground whenever the exhaust "head relief" sequence occurs at compressor start-up (If system pressure is lower than 10 psi).

    The suspension control module also uses the steering wheel position/speed sensor and vehicle speed inputs to control a power steering effort control valve. The suspension control module varies the steering assist by adjusting the current flow through the electronic variable orifice (EVO) solenoid control circuits. The amount of steering assist is dependent upon vehicle speed and input from the steering handwheel position/speed sensor. As the vehicle speed increases, the steering assist decreases and the driver effort increases. As the vehicle speed decreases, the steering assist increases and the driver effort decreases.

    The shock solenoid valve is driven ON and OFF by the suspension control module. To activate the solenoid, it is initially subjected to full battery voltage for a short period of time. Once the solenoid is pulled-in, the supply voltage is pulse width modulated (PWM). The amount the shock solenoid valve is activated is based on inputs from the driver Tow/Haul switch, road inputs and the PCM. The suspension control module provides a common ground (low reference) for all 4 of the shock solenoid valves.

    The suspension control module provides a common regulated voltage of approximately 5 volts to all four of the (body-to-wheel) position sensors, RTD air pressure sensor and the steering handwheel position/speed sensor. The suspension control module receives VSS from the PCM and over the class 2 circuit. The position sensors provide an analog signal voltage between 0.5 and 4.5 volts to the suspension control module. This signal voltage represents the wheel's position relative to the body. The suspension control module provides a 5 volt reference and a low reference to the position sensors. "

    A problem with any of the components listed in the description could cause the message you are seeing. Obviously there isn't a simple answer without the code and if you try to fix it yourself when things sort of seem to be working you can make some expensive mistakes. One thing we know the compressor is running so don't replace it. Is the back of the truck lifting up? If so the air ride portion of the rear shocks is probably OK. That doesn't mean the shocks are good only that the shock air bags are in good shape.

    There are 11 different codes that could be showing up. Some of those will cause the Service Message to show up and the others may not cause it to be displayed. If you want I can provide a list of the codes and the diagnostic procedures to use to isolate the problem. Send me a private message if you want a document with that information. The file is too large to add as an attachment.

    Last edited: Sep 7, 2012

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