Bought a Vectra b 1.8i 16v 2002 recently. After few days EMU light came on at first only for a little while but it soon became more frequent. Gave errors 0340 (Camshaft Sensor) and 0355 (Crankshaft Sensor). My friend who is a mechanic said probably just Camshaft Sensor as if Crankshaft Sensor goes car stops. Replaced Camshaft Sensor, old ones cable insulation was crumbling causing potential short. After this 0355 disappeared but 0340 stayed on more or less permanently i.e. once in a while EMU light would go out and car would run perfect. Tried three different Camshaft Sensors including after market but ended up with genuine GM/Siemens. EMU light still on with 0340 (camshaft sensor) error. By this time starting to think EMU knackered, common fault on this model at this age/mileage as it's bolted to side of engine. Checked wiring for camshaft sensor, got a closed circuit for all three wires going to various pins on upper EMU connector block. So it's not the sensor or it's wiring although have heard other people saying on forums that same/similar problem was caused by bad earth but have Haynes wiring diagrams and can't see any earth directly connected to camshaft sensor?!?! Have also checked that Altenator is charging within required parameters, it's ok. Then this morning car started with no EMU light and ran perfect. Stopped for petrol, started car, EMU light came on and car ran worse that ever. Felt like it was missing on one or more cylinders. Checked error codes and it came back with the old 0340 and then a new one 0352 (coil 2 and 3). Coils are controlled by EMU. Do you think this latest error is related to earlier problem i.e. do you think my EMU is knackered and/or is my coil pack on it's way out?

Edited by Tommo61 on 30/04/2013 at 19:10