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Vauxhall Astra G 1.8 Z18XE 2002 - Code P0340 camshaft sensor incorrect signal #

Posted by Paul Neasham on September 23, 2011, 11:49 pm

Year of Manufacture *: 2002
Engine Size and Code *: 1800 z18xe
( Optional ) ECU Type: simtec 71
( Optional ) Scanner Used: tech2
( Optional) Fault Codes: p0340 camshaft sensor incorrect signal

Hi

Water pump and cambelt were changed on this car a couple of months ago by another garage. After collecting it the owner complained of dead spot around 4000 rpm but no eml on. They relooked at it and replaced cam sensor after seeing p0340 logged. Car was no better and vauxhall dealer suggested changing cam sensor for oe part.still no better. Car deliverd to us with eml on, code p0340 cam sensor incorrect signal flagged.

Removed timing cover checked crank pulley keyway and retensioned belt.dtc returned when cranking.scoped cam sensor found some hash on signal then lost signal for a couple of minutes until restart. Replaced non oe!!cam sensor for another make (oe part not available for 2 days)and replaced crank sensor also. scoped signal no hash looked fine, but dtc returns occasionally on cranking.

Cam sensor is hall effect but cam sprocket does not have 4 lugs rather 2 raised semi circles that the sensor must pick up on. I dont see how it can differentiate between cylinders if all the hall effect signals are the same. I would like to synchronise the crank/cam signals on a fluke scope but am not sure how to or how to interpret what i get.

Disconnecting the cam sensor when running does not flag a code it only seems to happen when cranking and it does not start immediately.

Any advice gratefully received

cheers Paul

Re: vauxhall astra g cabriolet cam sensor code

Posted by Kevin Apps <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT2589' width='330' height='300' border=0 style='border:none;'> on September 24, 2011, 11:35 pm, in reply to "vauxhall astra g cabriolet cam sensor code"

Paul

Have you checked if this is one that should have a modified loom and plug when you change the cam sensor? ie gold to gold terminals.

Kev.

Re: vauxhall astra g cabriolet cam sensor code

Posted by paul neasham <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1202' width='330' height='300' border=0 style='border:none;'> on September 26, 2011, 3:15 pm, in reply to "vauxhall astra g cabriolet cam sensor code"

dealer i spoke to was not aware of any mods to the sensor and had not sold one in over 12 months,i saw in the archives what you speak of but i think that was for x engine codes,poss omega 2000.my thoughts are with what the cam sensor displays.the hall effect pattern shows all the "legs" as the same no difference in length or amplitude so if it is a cylinder identification sensor how does it know what position the cam is in?how would you set up a fluke scope to see both cank and cam sensors together with regard to triggering and what is a likely good pattern .thanks in advance regards paul

Re: vauxhall astra g cabriolet cam sensor code

Posted by Mark Carter <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1428' width='330' height='300' border=0 style='border:none;'> on September 26, 2011, 5:22 pm, in reply to "Re: vauxhall astra g cabriolet cam sensor code"
Mark Carter

Hi Paul,

Trigger the crank in the normal way, and then drop the cam in on the second channel.

You do not have to trigger the second channel as the scope will display whatever is happening on the other channels (triggered off the first)

Regards Mark

Modern cars, Its all wizardry and witchcraft

Re: Vauxhall Astra G 1.8 Z18XE 2002 - Code P0340 camshaft sensor incorrect signal #

Posted by Bryan Smith <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5330' width='330' height='300' border=0 style='border:none;'> on September 27, 2011, 8:52 pm, in reply to "Vauxhall Astra G 1.8 Z18XE 2002 - Code P0340 camshaft sensor incorrect signal #"
Bryan Smith

Hi Paul,

"Disconnecting the cam sensor when running does not flag a code it only seems to happen when cranking and it does not start immediately."

This may be a long shot but have you heard about knackered starter motors causing all sorts of problems with cam/crank sensors?
I know this doesn't fit in with the flat spot at about 4,000 RPM but perhaps you have 2 faults. What happens if you push start the car?
Regards,
Bryan.

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