In K9K engine series: If you mean the tdc in order to lock crankshaft to replace timing belt, in front of the engine near the flywheel zone right below the oil pressure valve there is a small bolt (usually with a torx head "star").
Removing that bolt and inserting a special locking tool through that hole ,will lock crankshaft right on the tdc.
No he means the TDC Sensor which is on top of the bell housing it is held in place on a banana shaped plate which is bolted to the engine with 2 10mm bolts.
The coolant temperature sensor in a Renault Megane Scenic is located on the right hand side of the engine as you are looking at it. It is located just above the TDC sensor.
How do you change the TDC sensor on the Renault Scenic RX4
at the back
here is pictures and advice on how to replace it :) http://www.renaultforums.co.uk/showthread.php?t=10062
Tdc sensor is located lower front of gearbox on Renault laguna diesel engine 2001 onward.
where is the tdc sensor on a 2003 scenic 1.6
You have to remove the battery to take it out and see it better, one the battery is out you will see two small bolts that hold the sensor in pace over the crankshaft. Peter
renault magene coupe..2ltr sensor 8200156362
i had problems starting my megane it was like the battery was goin dead. it wouldn't start or would take a long time to get goin so i called AA.first AA man changed battery but still the same week later next AA man unbolted a thing called TDC (top dead center) and cleaned it no problems since
Had same problem on mine, took the TDC (Top Dead Centre) sensor off, cleaned it and has been fine since. there are some good photos on how to do this if you google it. Good luck Rich
were is the tdc problem
I had same problem for nearly a year then looked on internet and the TDC sensor came up on lots of forums. There is a diagram also on parkerforums where this sensor is. All you need to do is clean it with a wire brush and car will run fine for approx 6 months. I have done this now for the last 18 months and every 6 months or so have to just clean the sensor at no cost. Hope this helps.