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A wiring diagram for the accelerator position sensor can be found in the vehicles maintenance manual. It can also be found in the cars repair manual.
There is no online resources that provides the 2001 Holden Astra CD workshop manual for free. Try contacting Holden for a copy of the original manual.
Remove the level plug.
the owners manual to your Astra sxi has all the uses of the function button and many m ore explanations about how to use the many features of the Astra sxi.
Look in the manual.
Read the manual
By far the easiest way to answer this is to advise that you get the haynes manual for your model Astra. The subframe will need to be dropped to remove the gearbox.
In the owners manual Page 216 from memory
On the 2008 Saturn Astra, the fuel filter is integrated into the fuel pump assembly, which is located inside the fuel tank. To access it, you'll need to remove the fuel tank, as it's not a separate, externally accessible component. It's advisable to refer to a repair manual or professional service for detailed instructions on replacement.
I did a How To writeup on fixing the Holden Astra rear window failure, with pictures, here: http://www.opelaus.com/forums/showthread.php?27769-AStra-Window-regulator-repair-replacement&p=635716#post635716
The engine number on an Opel Astra may be listed inside of the car manual if the number is not listed on the engine itself. Other vital information such as what kind of oil should be used is listed in the car manual as well.
The ignition control module for a 2001 Astra is typically located near the engine, often mounted on or near the ignition coil pack. In many cases, it can be found on the side of the engine block or mounted on the intake manifold. For precise location, it's recommended to consult the vehicle's service manual or a repair guide specific to your model.