Cruise Control Problem w203

[classic180]

Hi, can someone please point me in the right direction. w203 2002 C180 Classic.

Back in March 2008, I had a faulty Pass Side Front Indicator Bulb. I took out the Bulb holder, and there was a small hole on one of the connectors. I had an NCT ((Ireland Test) UK equiv is MOT) in 2 hrs, so I (Stupidily) placed a piece of Tinfoil on same, and bulb worked (New Bulb Holder (STG6 / Euro 8). On my way to a Tyre Centre to get 4 New Tyres, New Rear Camber Strut, and 4 Wheel Alignment (I'm a bit 'Precise' when its comes to my cars - probably didnt need new tyres and Rear Suspension was a little sqeaky only), I engaged the Cruise Control and it Disengaged itself at 50 KMH. I thought nothing of it. Got all the work done, passed the NCT (MOT), BUT Since March 2008 I still have the Cruise Control Problem.

I have Replaced the Brake Light Switch (Although it appears to be a Clutch Switch as there is only 1 Cable and Pin Connector under the dash and it only fits this 'Clutch Switch' which fits over the Clutch. If I fit same over the Brake Pedal - I have NO Cruise AT ALL. Therefore thats not the problem. (Ps Where is the Actual Brake Light Swicth?)

Regarding the New Tyres, (They seem correct Size, Same Thread etc), Regarding the Rear Strut, I dont think it was fitted to well as my Tracking is always off a bit and My Steering Wheel is not 100% Centred.

Therefore, Is my Cruise Control Problem (Again Works Fine betwen 30 and 50 KMH (or 20/25 and 30mph) from:

(1) Brake Light Switch - Where Is It???

(2) The Stupid Act of The Tinfoil - Have I 'Shorted Something' - Is there a Separate Cruise Control AMP / ECU / FUSE??

(3) Are the Tyres a Problem?

(4) The Alignment (from Rear Strut) coupled with the 'Not 100% Straight Steering Wheel' - Is the Affecting the Steering Angle Sensor? Does The 'ECU' / Steering Angle or YAW RATE Sensor think I'm acquaplanning or something similar?

Its driving me made and I wont go to MB (Ridiculous Pricing). Ps. No Faults Showing Up on any VAG Diagnostics.

Please Revert

Classic180

 

[dickchailey]

Don't know the model but are you sure you have not set/engaged the limiter?

 

[classic180]

Cruise Control C180 Classic

Hi

No the Speed Limiter is Off. Funnily enough I can rule out the Stalk as the Speed Limiter does work at all Speeds (even above the 50 KMH).

Havent a clue what the problem is

 

[lynall]

What size tyres have you got on the front and rear?



Lynall

 

[BlackC55]

There is no BLS for your car. It is done via a control unit.

I woul be looking at your tyres as the possible culprit.

 

[Autofix]

(1) Brake Light Switch - Where Is It???

(2) The Stupid Act of The Tinfoil - Have I 'Shorted Something' - Is there a Separate Cruise Control AMP / ECU / FUSE??

(3) Are the Tyres a Problem?

(4) The Alignment (from Rear Strut) coupled with the 'Not 100% Straight Steering Wheel' - Is the Affecting the Steering Angle Sensor? Does The 'ECU' / Steering Angle or YAW RATE Sensor think I'm acquaplanning or something similar?

It does not have a brake light switch.

Doubtful. The front lamps are supplied from the front SAM module. While the SAM is involved in the CC the circuits are separate. The CC is best described as being virtual. It exist in the software of 3 (I think)** modules.

You posted that the problem first occurred before the tyre change. If so then its not likely, if not then it could well be connected.

If the steering angle was off it would show an ESP warning on the dash.


PS What part of Ireland are you in. There are a few good independent specialists around ye know


**Edit. Just checked and its actually 4 modules. The SAM is not one of the main modules. It could effect a brake light signal but not likely in this case. The 4 modules involved are – engine (ME-SFI), ignition switch (EZS), Instrument cluster (ICM) and SCM (steering column module).

 

[classic180]

Mercedes c180 Cruise Problem

Thanks for all the replies.

Could be the Tyres but I;m sure on the way up to get the tyres - I engaged cruise just above lowest speed, started accelarating using stalk and then it cut out. As stated thought nothing of same. The tyres are correct size as per User Manual Data.

Regading last reply - Kilkenny / Carlow / Laois Area would be closest. There is a guy in C'Comer,KK who looked at same. His son, did the Diagnostics but I dont know if he checked everything.They asked me to bring it back but I didnt get a chance. I have my own mechanic - excellent guy but he cant figure it out.

Might bite the bullit- Mercedes Diagnostic with Strict Instructions to do no work - Just Diagnose

I will revert. If anyone else can think of something, please update.

 

[Autofix]

Castlecomber, Billy Coogan or Ned Kelly maybe.

Does this play up every time its used or only sometimes. If everytime, it would be easier to find the fault. The first step should be to read, record and clear all codes then drive it. After it plays up another read could show a relevant fault. Leaving it too long could cause spurious codes to be set, especially CAN codes.

 

[scorpie]

Anyone know of a MB Specialist in Cork City area? My ECU is acting up again!