TDC sensor siemens to old Bosch type

[keef666]

Hi,
I have just got my new Siemens TDC sensor for my Renault Scenic 1.6 16v car, the new Siemens (yellow & pink) has different coloured wires to the loom that feeds the old type Bosch (green & brown). Which wire goes to which colour
Thanx in advance.

	TDC TDC In a piston engine, top dead centre (TDC) is used to determine the position of a piston in which it is further from the crankshaft. This is used to determine when to generate a spark. Many Renault models appear to experience problems with the TDC sensor, but it is a simple and inexpensive part to replace.

[keef666]

I truly believed someone might know but alas still no reply and 36 views.

[keef666]

lol so much for 'ask the experts' heading.

[keef666]

Hi,
I have now fitted the new siemens TDC sensor to the car (Renault Scenic 1.6 16v 'W' reg Auto) it is very fiddly to get the sensor into the flywheel housing because the loom carrier gets in the way.
The other difficulty was the new TDC sensor (siemens blue one) the old black one had 2 brass boss's which fit inside the flywheel bell housing recess's.
I had to remove the brass boss's using grips to remove them from the bracket, I then inserted the boss's into the new Siemen's sensor (the correct orientation of course) and riveted the brass boss's to the steel using a ball pane hammer.
Insert the sensor and bolt tightly.
The wiring on my old sensor was green and brown wires? I connected the pink (new sensor) to the green wire and the yellow (new sensor) to the brown wire.
Bingo sorted.
I also changed the spark plugs and it runs like a dream!

Please note:
Renault bulletin water ingression is a known fault on old style pencil coils- smear with denoso grease (from Renault garage) around the bottom shoulder on the pencil coil.
The pencil coils have been update because of this issue and can be recognized by a rectangular cut-out on the shaft of the new style pencil coil. (you probably know this anyway but hey).

	Ignition Coils Ignition Coils An ignition coil (also called a spark coil) is an induction coil in an automobile's ignition system which transforms a storage battery's 12 volts to the thousands of volts needed to spark the spark plugs. This specific form of the autotransformer, together with the contact breaker, converts low voltage from a battery into the high voltage required by spark plugs in an internal combustion engine. In older vehicles a single (large) coil would serve all the spark plugs via the ignition distributor. In modern systems, the distributor is omitted and ignition is instead electronically controlled. Much smaller coils are used with one coil for each spark plug or one coil serving two spark plugs (so two coils in a four-cylinder car). These coils may be remote-mounted or they may be placed on top of the spark plug (coil-on-plug or Direct Ignition). Where one coil serves two spark plugs (in two cylinders), it is through the "wasted spark" system. In this arrangement the coil generates two sparks per cycle to both the cylinders. The fuel in the cylinder that is nearing the end of its compression stroke is ignited, whereas the spark in its companion that is nearing the end of its exhaust stroke has no effect. The wasted spark system is more reliable than a single coil system with a distributor and cheaper than coil-on-plug. Where the coils are remote mounted they may all be contained in a single moulded block with multiple high-tension terminals. This is commonly called a coil-pack.

	TDC TDC In a piston engine, top dead centre (TDC) is used to determine the position of a piston in which it is further from the crankshaft. This is used to determine when to generate a spark. Many Renault models appear to experience problems with the TDC sensor, but it is a simple and inexpensive part to replace.

[seckford123]

Hi,
Great post.

I would like to take off and clean/replace the TDC sensor on my 2001 Scenic 1.6 16v Automatic but cant find its location. Haynes says left of gearbox bellhousing engine block. Ive looked and looked but nothing resembles the pictures in the manual?
Are some models different?
Have you any photos?
Many Thanks
Simon

	TDC TDC In a piston engine, top dead centre (TDC) is used to determine the position of a piston in which it is further from the crankshaft. This is used to determine when to generate a spark. Many Renault models appear to experience problems with the TDC sensor, but it is a simple and inexpensive part to replace.