05 October, 2011

How to install a modified Camshaft Angle Sensor in a Vectra B

Diverging from computers and Linux, I'm going to explain how to install one of the modified/updated Camshaft Angle Sensors in a Vectra B with an Ecotec 2.0L engine (my car has the C20SEL engine, but this should apply to the C22SEL, X20XEV and various others).

You can buy the original and modified (aka. revised, hopefully improved) camshaft sensors on eBay.  I personally went for the genuine items made by Siemens.  My Vectra is a Holden branded Vectra, but they are also branded as Opel and Vauxhall in other parts of the world.

I bought both an original sensor and a "modified" sensor.  The original sensor has a rectangle socket and the modified one has an oval socket.  The water seal on the oval socket is much better than the original, but thats about the only visible difference.  Apparently the modified sensor was made to reduce the number of failing camshaft sensors in these engines.

This post will explain the easy way to remove your old camshaft sensor and install the new one, and I'll also explain how to wire up the modified camshaft sensor, as this information wasn't available when I had to do mine.


The easy removal & installation method:

You will need these items:
  1. E-Torx E8 Socket or 6mm Double-Hex Socket
  2. Magnetic pick-up tool (they look like a telescopic aerial with a small magnet on the end)
  3. 20mm - 25mm Hole Saw & Drill.
The camshaft sensor is held in by a bolt, and it's not the bolt you want it to be.  The bolt is behind the timing belt cover (the black plastic cover on the front of the engine) and that cover is not trivial to remove.

Instead of removing the timing belt cover, you will notice that there is a bolt that holds the cover on near the top of the engine.  The bolt is recessed into the camshaft cover and is in the middle, directly in line with the camshaft sensor.  This bolt doesn't need to be removed, but the camshaft sensor sits on this bolt and is used to position the sensor correctly.

You need to drill a small hole in the timing belt cover approximately 20mm above this bolt.  Do this with a holesaw, not a drill bit as this plastic will be brittle from the heat over the years.  You can safely drill a good sized hole with a hole saw.  I recommend a hole about 20mm-25mm in diameter.

Before you drill the hole you probably want to know what your drill might hit, and fair enough!  If you do this carefully you shouldn't hit anything, because you'll do this slowly and you won't be pushing hard on the drill, so as soon as the hole saw breaks through to the other side of the plastic cover you can pull it out.  Should you not be careful, the drill bit that guides the holesaw will hit the camshaft sensor, possibly get jammed between the sensor and the bolt holding it onto the head of the engine, which could possibly snap your drill bit, but not likely.  You could also hit the camshaft gears with the hole saw, but that shouldn't do much in the way of damage (they're quite sturdy steel gears).  You won't hit your timing belt, so don't worry too much about that, its well out of the way!

Now that you've drilled the hole, you'll be able to see the camshaft sensor and the bolt (you'll probably need a small mirror to see them).  The bolt is a weird looking thing, called an E-Torx bolt, and I was able to get an E-Torx socket set from my local hardware store for about AUD $25 (in the tool section with the socket sets).  You need an E-Torx E8 socket, its fairly small.

Don't worry too much if you can't find a set of E-Torx sockets, another socket that fits the bolt very well is a double-hex 6mm socket (must be double hex/12-sided, not standard).

Ok, so now you're going to be undoing a bolt that you can't really see and certainly can't get a grip on.  My suggestions are as follows:
  • Put some bluetack or similar on and in your socket so that the bolt will be somewhat jammed into the socket.  Apply moderate force when undoing the bolt that holds the camshaft sensor.
  • If possible, use a magnetic socket, magnetise your socket, or get a small earth magnet and glue it into your socket.  (I didn't do any of this but I was willing to take the risk that I'd lose the bolt).
While you're undoing the bolt that holds the camshaft sensor in place, push the top of the camshaft sensor toward the back of the engine.  Should your bluetack fail you, the angle of the camshaft sensor should stop the bolt falling down into the bottom of the timing belt cover (and if it did I have no idea where it might end up and what damage it might do if you left it in there).

If the bolt doesn't come out with your socket, then use the magnetic pickup tool to grab the bolt.

Once you have that bolt out, the camshaft sensor will be loose.  Just lift it out by its cable and then disconnect the sensor from the cable by pushing the metal clip in toward the sensor.

At this point, if you're installing a sensor with the same connector as the one you just pulled out, then installation is the opposite of removal.  Otherwise, continue reading about how to convert your vehicle wiring to use the modified sensor like I did.

How to wire up the modified camshaft sensor:

You will need or want the following items:
  • Soldering Iron & Solder (this is a must)
  • A small piece of aluminium foil - as used in cooking (recommended)
  • Electrical tape (must)
  • Heat-shrink Tubing (2mm diameter) (optional - you can use electrical tape)
If you're not good at soldering two wires together neatly then have some practice with some spare wire before you do this.  You can read up on good methods of splicing cables.

When you buy your modified camshaft sensor, make sure you get one that includes the conversion kit if your car hasn't already been converted.  The conversion kit is just a new connector with a cable coming out of it.

The procedure from here is pretty simple.

Disconnect the battery negative as a precaution, to help prevent damaging your engine ECU.

Perform the following steps:
  • Cut the old connector off the camshaft angle sensor cable. 
  • Strip the outer insulation of this cable to expose the wires.  You will have 3 insulated wires and 1 non-insulated wire (if you also have some aluminium wrapping around these wires just discard it, we'll deal with that later). 
  • Match up the colours of the wires in the original cable with the new cable supplied with the sensor. Pay attention to the colours on the wires.  You should have two grey wires, one with a red stripe and the other with a black stripe and one wire which is green and brown.  The 4th wire is a shielding/earth wire for the cable as these cables have a thin aluminium shielding inside them.  Connect these wires together also, but leave the unshielded wire bare (don't put heat-shrink tubing or electrical tape over that connection).  All other connections must be insulated with either heat-shrink tubing or electrical tape.
By now you should have the following arrangement:
  • The "Grey / Red Stripe" wire in the original camshaft sensor cable connected to the "Grey / Red Stripe" wire in the new cable.
  • The "Grey / Black Stripe" wire in the original camshaft sensor cable connected to the "Grey / Black Stripe" wire in the new cable.
  • The "Green / Brown Stripe" wire in the original camshaft sensor cable connected to the "Green / Brown Stripe" wire in the new cable.
  • The non-insulated wire in the original cable connected to the 100% black (or possibly non-insulated) wire in the new cable.
  • All wires except for the non-insulated wire in the original cable must be insulated with either heat-shrink tubing or electrical tape.
Once you have this step completed, wrap a small amount of aluminium foil over the wires so that you can no longer see the wires you just soldered together.  The aluminium foil is supposed to be in contact with the non-insulated wire.  This will help prevent unwanted interference from entering the camshaft signal cabling and possibly causing problems.

Use heat-shrink tubing or electrical tape to cover the aluminium foil and hold it in place.  The aluminium foil must be completely covered by electrical tape or heat-shrink tubing.

Install your modified camshaft sensor as per the previous section if you haven't already, and then firmly push the connector on to the top of the sensor.  The cable should click in.  Note that the connector will only fit one way around.

Job complete.  If you have any questions please ask before you start this procedure.  Again, YOU DO THIS AT YOUR OWN RISK.


  1. I've replaced the sensor but the fault code still shows even after being cleared by computer. Does anyone know where the other end of the sensor wire connects to.

    1. Hello Johnny,

      The other end of the sensor cable is combined into a larger loom which runs to the engine ECU, which is located under the weather shield below the windscreen.

      To get to the ECU connector you need to remove the windscreen wipers and the large plastic weather shield below. The ECU connector is covered by a large rubber boot which you need to unbolt.


When commenting, please make sure you tick the "Notify me" checkbox, otherwise you will not be notified when I reply to you!