My Continuing Tales of Woe

**Ste** · 14th January 2010, 13:41

Well, my car - 04, LS, 1.8 Petrol, 132,000 miles

Following on from these threads.

http://www.vectra-c.com/forum/showthread.php?t=95368

http://www.vectra-c.com/forum/showthread.php?t=96046

http://www.vectra-c.com/forum/showthread.php?t=96690

The short version if those threads are too much.

Fault code P0340 - Camshaft Position Sensor Circuit Malfunction flagged up 2 months ago.

Engine limited to 4000 rpm and lacks power and fuel economy reducued by about 15%.

Spanner graphic on, MIL off.

I have done the following

I have tested the wiring between sensor plug and EMS for continuity - OK
Replaced Camshaft sensor
Replaced Crank position sensor
Checked Timing - OK
Checked timing belt tension - OK

I got a second hand ECU from SRi-RICH (cheers, and PM sent

)

Took the car to the dealer this morning. They fitted the 'new' ECU and programmed it to my car. All good so far.....

Fault code still there and same symptoms presented as before. Code activates as soon as the engine is cranked (same as before)

So I had them reset the ECU and refit my old ECU, as clearly the ECU isn't the defective part.

The only thing I can do next is to hardwire the Cam sensor to the ECU pins by soldering in new wires (one for +5V, one for ground and one for signal return). I am not sure that this will work though, but will give it a try almost in desperation!

If this doesn't work, where should I look next? The dealer doesn't know either.

It is really getting on my nerves now.

Alternator is original
Spark plugs are gen VX
Coil pack is original

The odd thing is that:-

Disconnecting the crank sensor causes the engine to only idle - the acc pedal makes no difference to the revs (this is normal and is a true limp mode to get to a safe place on Cam timing alone) showing that a valid Cam signal is being received by ECU.
Disconnecting the cam sensor makes no difference to engine operation.
Disconnecting both crank and cam sensors together results in a 'crank but no start' of engine (as expected)

Can anyone shed some light on this at all?

**Vaux-Man-G** · 14th January 2010, 14:02

Im not going to be able to help, but this last thing you wrote rung a few bells:

"Disconnecting the crank sensor causes the engine to only idle - the acc pedal makes no difference to the revs (this is normal and is a true limp mode to get to a safe place on Cam timing alone) showing that a valid Cam signal is being received by ECU.
Disconnecting the cam sensor makes no difference to engine operation.
Disconnecting both crank and cam sensors together results in a 'crank but no start' of engine (as expected)"

My cousins Vec-B 1.8 LS had the identical problem a few months.

DTC pointed towards crank sensor. When the crank sensor was changed, still didnt start.

When the Crank sensor was disconneted the car started and would not respond to throttle and would die after first bout of high rev's. When crank sesnor connected, the car cranked but would not start.

We eneded up par-exing it for another car but when it was sold, they said they suspected ECU failure OR the timing had jumped out of sync.

And sorry to write this last bit, but subsequently the car was scrapped for £150.00 NOTES!

**Ste** · 14th January 2010, 14:05

Thanks G, you really know how to cheer me up.

If I can't find the cause, then I will have to decide whether to keep the car running as it is, P'X it or attempt to investigate further - which may be a money pit at the dealers.

**Vaux-Man-G** · 14th January 2010, 14:07

Sorry Ste, but it was the harsh reality for my cousin at the time! He was in exactly the same problem mate and Vx wouldnt touch replace or refund parts unless it was in there garage! It was simply a money pit! He spent about £250 on it only for it to be literally given away in P/ex as scrap metal!

An idea though for you, post this up on VVOC as the B's have the same'ish engine so it may help if someone had the issue on there.

**Ste** · 14th January 2010, 19:51

Bump !

**Big Sig** · 14th January 2010, 20:04

AON and AOC too as that engine was fitted to the astras.

**Ste** · 19th January 2010, 09:21

I'm not a member of those forums, but thanks

I jumped the wires from the main ECU to the cam sensor, and guess what - no change. Unsurprisingly.

Not sure where to turn now, the dealer has no real idea either, but they will contact VX technical for any assistance.

**Big Sig** · 19th January 2010, 10:56

Originally Posted by Ste

I'm not a member of those forums, but thanks

I jumped the wires from the main ECU to the cam sensor, and guess what - no change. Unsurprisingly.

Not sure where to turn now, the dealer has no real idea either, but they will contact VX technical for any assistance.

You don't need to be to read their forums, besides just sign up if it finds what your looking for. Not being a member is a bit of a lame excuse.

**Ste** · 19th January 2010, 11:37

You're probably right Sig.....

**Birchy63** · 19th January 2010, 11:48

Camshaft sensor, how does that work? hall effect/driven? is it external or internal to the engine? (ie does it poke into the engine)
For example if it were internal there could be something worn on the cam itself.

The other thing is.... what does it compare the camshaft position against? some systems can fall over when they "assume" that one part cannot possibly fail and therefore it must be XYZ....
Never assume these damn things are correct, check absolutely everything.