I just saw this pop up in my instrument cluster yesterday. Anyone else? Cycle the key and it goes out. Funny, my 2008 C350 did the same darn thing twice. Dealer could never figure out why.

This happens if you have ESP off and try to use cruise control. Is this what u were doing?

No. It just popped up on its own.

Or if you have turned it on and off repeatedly in a short time a couple times it will not let you use it.

HBC350;4120533: By any chance do you have the Powerchip/Evosport Tune?

This was the 1st message before my ECU self destructed.

Regards

This happened to me last week. It said the same thing. I sent it in and they said it was probably something wrong with the censors.

Same thing happened to me, cycle the key and went away.

This happens to me all the time only when I have the traction control off or on sport.

This happened to me last week when I started the car. As soon as I started the car the message appeared. I closed the message and drove off and then I turned on cruise control and it worked fine.

I then checked my "messages" and there were none.

It only happened once and like I said the message wasn't even accurate because I was able to use my cruise control just fine.

This happened to me again two days ago. Cruise Control Inoperative message. I tried to used Cruise Control and it was inoperative. I turned the car on and off a few times during the day, but forgot to check cruise control.

Tried it today and it worked fine. The message is gone too.

Is this happening in cars with stock tunes too?

Yup. My bone stock 2008 C350 and 2009 C63 did the same thing. Well, my C63 does have the Harrower center armrest upgrade but I'm pretty sure that's unrelated.

Are you seeing an ESP warning light saying that the cruise control is inop, or just that the cc is inop?

Good to know, thanks for the reply.

For me, it is only a "cruise control inoperative" light. No "ESP" warning at any time, except for the little flashy triangle that comes on as I try to roll over a puddle in Comfort mode. Need an LSD, bad.

Nothing, other that "Cruise Control Inoperative."

I went somewhere successfully using the cruise control. I parked the car for an hour. When I started the car again the Cruise Control Inoperative message turned on immediately. I turned the message off, then I tried to use it several times during my drive and it wouldn't let me. The message just kept popping up when I tried.



I've been using cruise control since 2009 and this never happened before. Any thoughts?

To the people who have encountered this, is it a one time thing? Or should I expect to see this again?

Thanks in advance

It came up once when I was almost to my destination. I hadn't used it at all that day and probably drove 45 miles already. I parked, turned off the car, started it back up, and the message was gone. No stored code, never came back.

this happened to me just last week for the first time. i turned the car off and back on and it was gone.

I was told it was a glitch.

2009 Manual C300. Out of nowhere the cruise control stopped working.
Now it just throws a "mph __?" message and nothing happens.
Still no idea what can fix it.

Sorry to bring up an old thread,

I just got that message this morning, restart the car and message gone,
but OBD II reader shows a few error code (no CEL though)

U0121
U0415
P1369 - engine temp sensor/cylinder 5 ?
P1373 - cylinder 7 ?

any help would be much appreciated.

Here's some things to check first
1. Try turning "dyno mode" on it will turn off all electronic assists then turn back off. (Reset)
2. If your car has ESP (Traction Control) off Cruise will not work.
3. Check for any warning lights on dash
4. Check fuse box (I think it's in trunk) for cruise fuse.

To get the car into "Dyno Mode" first turn the car 2 clicks so the aux power is on, then hold the "ok" and call answer buttons on the steering wheel at the same time. After 3 or 4 second a menu will pop up. Select "dynamometer Mode". Turn on then start the car drive around the block. (ALL SAFTEY MEASURES ARE DISABLED!) This mode is equal to (track mode) you can BURN the tires off so be careful lol. Then turn the car off, then when you turn to aux again turn off. Take the key out then everything that works should turn back on.

(Check the secret menu it has a lot of info on the cars condition, services etc)

It should work with ESP on. Mine does. Have to test Sport.

Good to know. I will test a couple of your suggestions.