TCS light on?Help Please!

[Lanks]

Had my golf TDI estate just 2 days (got it Sunday) and I have a worry (not what I expected!).

The TCS light (asr button on the dash though) came on, on the way to work (mon) in the morning cold pulling up a hill slowish the TCS light in the intsruments came on and stayed on all the way to work (flash only in the book). When and had a look in the book at lunch put the ignition on and it was off-so was happy!. Drove all the way (10miles) home nothing came on.

This morning nothing too BUT! On the way home pulled up a hill and it came on again and stayed on all the way home. When I got into my drive turned off, then ignition on and it went out in a second????

Is it a lose connector??? I dont mind looking myself.

What is it-any ideas.

[Lanks]

Anyone?

Where are the sensors? I have heard it could be a bad connector in the wheel well but where?

Also MAF, what is it and where?

[tornadored7]

Hi Lanks,

The Traction Control System (in your case ASR) works by using the ABS wheel speed sensors attached by all four wheels, and checking for a skid condition by monitoring all four wheel speeds. It then applies braking pressure to the needed wheels based on the wheel speed deviation.

ESP is an enhancement of ASR and also includes YAW measurements (taken from a YAW Sensor) into the decision control process. ASR TCS cars aren't equipped with the YAW sensor.

There is an ABS rotor and ABS sensor on each wheel. The ABS Sensor sits a certain distance behind the the ABS rotor, which in turn is hidden behind the disk brake. Hence unless you get underneath the car or remove a wheel, the ABS sensor won't be visible.

Since an ASR fault is likely to log a fault code, the easiest means of diagnosis is to connect a VAG-COM equipped computer to your OBD2 connector. Otherwise, to get fault codes scanned from a dealer/mechanic.

See the related thread https://www.vwaudiforum.co.uk/forum/s...ad.php?t=30981 ).

TR7

[tornadored7]

Sorry, forgot about the MAF;

The Mass Air Flow sensor is situated in the air hose, connected after the air box.

It extrapolates the mass/volume of air flowing into the engine, based upon a current driven temperature regulation control system (i.e. how much current is required to keep the temperature of a hot metal film constant, when intake air [which has a cooling effect] is passed over it).

Based upon various criteria;

• Air temperature
• Mass (volume) of air entering engine
• Fuel temperature
• Engine speed
• Coolant temperature
• Crank position / Needle lift
• ...

The engine can precisely determine the amount of fuel (and when) to inject into the engine.

Hence the MAF is one of many sensors required in the Engine Control System, which is why when a MAF is faulty/degraded it will adversely affect your Fuel economy (and emissions ?) and engine power output, making the car feel quite sluggish. Because, MAFs degrade imperceptibly over time, this can be difficult to detect.


For further details use the search SEARCH facility;


also (see: https://www.vwaudiforum.co.uk/forum/s...ead.php?t=6571 ).

TR7

[Lanks]

Thanks for the help/tips, I will have a look.