- 06-01-12 11:32 AM #1
Speed limited to 120mph
Yesterday while driving home for a brief second the DIC flashed the message for speed limited to 120mph. There was no warning noise or any other dash messages. Am I correct in assuming that this was due to something suspension related? Only saw it once and barely had time to read it before it disappeared.
- 06-01-12 12:38 PM #2
Yes, speed limited messages are always associated with a suspension issue...
- 06-01-12 01:20 PM #3
Hmm. I guess this would explain why I was only able to hit 120 when the car silently decided to stop accelerating about 2 weeks ago when I had a chance to test it out. No DIC message at all before or during, it just stopped accelerating. It did not act like the DTS I had when hitting the top speed fuel cutoff. So I can only surmise that there is a suspension issue. Hopefully the service contract covers suspension related issues.
- 06-01-12 02:05 PM #4
Love to see the work order ahhaa. Customer states car cannot speed in access of 120 mph... Hahah
- 06-01-12 02:06 PM #5
Lol. I don't know if I will have it worded quite like that.
- 06-01-12 02:50 PM #6Originally Posted by 1BadCadSTS
- 06-30-12 07:12 PM #7
Took it to the dealer a week or so ago to have some work done and had them look into this.
They have never heard of such a message on the DIC. They could find no codes related to suspension or otherwise on the car using the tech 2. They claimed to have called GM tech assistance to see if they knew anything about it and they didn't either. :suspicious:
So ideas on what's up with my F55 FE3 suspension?
It does silently top out at 120mph with NO message showing on the DIC, when hitting 120 it's like I just set the cruise, it does not behave like the top speed file cutoff that I had in the DTS.
Speed limited message is the only one I have seen on this car and it was only the one time but the speed is limited all the time.
Edit: according to alldata this should leave a code in the ESC module.Electronic Suspension Control Operation
The electronic suspension control (ESC) system uses the information from other systems in order to execute certain functions.
The ESC system does not have a malfunction indicator lamp, but instead uses the instrument panel cluster (IPC) for the display functions. When the ESC system detects a malfunction that sets a DTC, the ESC system sends a message on the serial data line directly or through the powertrain control module (PCM) to the IPC, which will display one of the following messages:
SERVICE SUSPENSION SYSTEM
The SHOCKS INOPERATIVE message will only be displayed if the ESC system detects a malfunction that sets a DTC and causes the ESC system to disable all 4 shock absorbers. The ESC system will send a message on the serial data line to the IPC to display this message.
The SERVICE SUSPENSION SYSTEM message will only be displayed if the ESC system detects any malfunction that sets a DTC. The ESC system will send a message on the serial data line to the IPC to display this message.
The SPEED LIMITED message will only be displayed if the ESC system detects a malfunction that sets a DTC and causes the ESC system to disable all 4 shock absorbers. The ESC system will send a message on the serial data line to the PCM indicating that all 4 shock absorbers were disabled. The PCM then sends a message to the IPC to display this message.
The ESC module has the ability to store DTCs as current or history codes. Most ESC system malfunctions will display a message in the IPC and set a DTC. The message will remain ON until the RESET button is pressed on the driver information center (DIC). As long as the DTC is current, the message will be displayed after every ignition cycle and the RESET button must be pressed to bypass the message.
The ESC system uses an ignition cycling diagnostic approach in order to reduce the occurrence of false or intermittent DTCs that do not affect the functionality of the ESC system. This allows for the fail-soft actions to be taken whenever a malfunction condition is current, but requires the malfunction to be current for a certain number of ignition cycles before the corresponding malfunction code and message will be stored or displayed.
If the ESC detects a malfunction, the ESC system defaults with a fail-soft action. A fail-soft action refers to any specific action the ESC system takes in order to compensate for a detected malfunction. A typical ESC fail-soft action would be if the ESC system detects a malfunction with a shock absorber.
- 06-30-12 07:30 PM #8
Askm to throw it on a lift and romp it up to 120 (assumin awd it should do it without issues on wheel speed abs and tc) and explain why it stops then.
- 06-30-12 07:38 PM #9
I recall people on the deville / Seville forum overriding suspension messages when they replaced active suspension shocks with passive ones... Does this sound like that behavior to anyone? (Could previous owner have done a resistor mod to cause this behavior??)
I may have to stop in on Monday and have them use the tech 2 in front of me and check out the ESC module.
Not sure if the dealer would want to take responsibility for possible drivetrain damage cranking it up to 120+mph on a lift. It is AWD but getting the drivetrain going that fast with no resistance on the components nor the added cooling of the high wind speed at that rate may not be a great idea.
- 06-30-12 08:41 PM #10
Is no resistor mod for f55 also no replacement other than oem.
- 07-01-12 10:44 AM #11KRSTS Guest
- 07-01-12 10:56 AM #12
Doesn't have any history of that at least no RPO code that suggests it. It comes with the VR rated tires according to the door sticker. It does _NOT_ say that I have reached the speed limiter.
- 07-01-12 12:50 PM #13
Check the RPO codes on the spare tire cover in the trunk. You may get a different story on what tires were installed by the factory. Factory sets the limiter at build time based on the tires scheduled to be installed on the car.
Fleet cars were commonly set to a 108 limiter with 112 speed rated tires mounted. Mine had the, presumably cheaper, 112 rated 235/50R17 Michelins factory mounted. That's right, not the staggered setup normally used on the STS. I've seen the limiter message on the occasional deserted country road.
A sensor or hub issue could cause faulty alerts resulting in the limiter message. But since your not seeing a message... hmmm
- 07-01-12 02:23 PM #14
Re: Speed limited to 120mph
Tire Rack shows ZR W rated tires at being 168MPH rating.
Note that Tire Rack shows the STS V8 AWD as having non staggered setup of 255/45-18 for the "Performance Handling Package"
The only other option is a staggered setup for "17 inch OE wheels" which has sizes of 235/50-17 front and 255/45-18 rear ... wtf?
But if you choose the V6 AWD model you get 235/50-18 & 255/45-18Originally Posted by 1BadCadSTS
The code they listed is related to excessive braking, found myself needing to avoid a Deer in the road during a time of the year we don't normally see any.
They cleared the code anyways and it didn't help with the speed limiter.
When this code that is listed is a 'current' code it disables the Cruise Control system as to avoid applying any additional heat onto the brake system.
I do have a service contract on this car that is of the short exclusion list type, rather than the crappy inclusion list type.
- 07-02-12 04:26 PM #15Cadillac Owners Member
- Automobile(s): 2008 STS
- Join Date
- Jun 2012
- Euless, TX
Re: Speed limited to 120mph
I have a Silly Question, Were you driving 120 MPH? Kidding: I have an 08 STS Platinum edition and took it to a track day here at Texas Motor Speedway. It is limited at 120 and flashes the message on the DIC. If you were not in warp 2.5 at that time, I'd recommend having it checked out at your dealer...