PO340 is camshaft position sensor circuit malfunction. Open/short circuit to supply or earth. Sensor maybe fine problem is in loom.
PO340 is camshaft position sensor circuit malfunction. Open/short circuit to supply or earth. Sensor maybe fine problem is in loom.
remedave
New Member
Yep thats the error, i have chased the loom back of the engine to the fuse box and the connector under the header tank, i have also used a test meter in the loom to test for open circuit no problems found, i can't find any values for checking the Cam sensor (outputs etc) that would be handy then i could confirm if the sensors are good, these sensors are second hand.
If all fails with yet another cam sensor and then i will change the crank sensor and finally the ECU then set fire to it.
P38guy
New Member
Trouble shooting manual may help
https://docs.google.com/file/d/0B0GHeyqlQgdWODhlYTViOWYtMDg2Ni00ZTUxLWJjYWItNGZiNDRlZDc1ODRm/edit
remedave
New Member
https://docs.google.com/file/d/0B0G...WItNGZiNDRlZDc1ODRm/image?pagenumber=27&w=800
Interesting the cam sensor does a lot then really and its connected directly to the MAF
Interesting the cam sensor does a lot then really and its connected directly to the MAF
You are on a hiding to nothing if you have not had a copy of RAVE before this. Having a copy of the workshop manual is fundamental to trouble shooting. Specially if you are not current on the vehicle being worked on.
Query:
The Fueling and Ignition information would come from a variety of sensors...
Fuel metering would be metered using MAF and Lambda information...with the MAF metering the charge air and the Lambdas detecting the burn 'quality'...
Ignition timing information would be calculated from Crank Position, Cam position and Knock Sensor...the Knock Sensor(s) would be detecting pinking or knocking and tell the ECU to advance or retard ignition timing within set boundaries to prevent this from happening.
Would I be right in saying Fuel timing is set from Crank and Cam sensors or just Cam sensor??
Could it be a knock sensor causing incorrect information and not allowing the ECU to correctly set the timing to prevent knocking/pinking??
The Fueling and Ignition information would come from a variety of sensors...
Fuel metering would be metered using MAF and Lambda information...with the MAF metering the charge air and the Lambdas detecting the burn 'quality'...
Ignition timing information would be calculated from Crank Position, Cam position and Knock Sensor...the Knock Sensor(s) would be detecting pinking or knocking and tell the ECU to advance or retard ignition timing within set boundaries to prevent this from happening.
Would I be right in saying Fuel timing is set from Crank and Cam sensors or just Cam sensor??
Could it be a knock sensor causing incorrect information and not allowing the ECU to correctly set the timing to prevent knocking/pinking??
eightinavee
Well-Known Member
Think I may be able to help here... The Cam sensor is a Hall Effect sensor producing four pulses for every two engine revolutions.The signal used in two areas; Injector
timing corrections for fully sequential fuelling and active knock control. The cam signal pulses are generated from four gaps on the cam wheel. One gap is smaller than the other three.
When its not functioning correctly and the P340 code is set,sequential injection is dropped,knock detection is dropped and misfire detection can be inaccurate.
So that your engine knocks and misses is no surprise,Gems and Motronic systems want to run sequentially and closed loop.Without a plausible reading from the camshaft sensor none of this can happen so it goes basic.
As the OP is a master tech - but hasn't mentioned who for, I'm surprised this hasn't been sorted out,an hours work with a wiring diagram and a scope should sort out this problem.
One last thing,does the engine have the correct cam sprocket fitted ? Gems and Motronic use different sprockets and will cause this issue if fitted to the wrong engine.
timing corrections for fully sequential fuelling and active knock control. The cam signal pulses are generated from four gaps on the cam wheel. One gap is smaller than the other three.
When its not functioning correctly and the P340 code is set,sequential injection is dropped,knock detection is dropped and misfire detection can be inaccurate.
So that your engine knocks and misses is no surprise,Gems and Motronic systems want to run sequentially and closed loop.Without a plausible reading from the camshaft sensor none of this can happen so it goes basic.
As the OP is a master tech - but hasn't mentioned who for, I'm surprised this hasn't been sorted out,an hours work with a wiring diagram and a scope should sort out this problem.
One last thing,does the engine have the correct cam sprocket fitted ? Gems and Motronic use different sprockets and will cause this issue if fitted to the wrong engine.
tomcat59alan
Well-Known Member
Sounds like a fancy title, typically military, for someone that has done a course.
eightinavee
Well-Known Member
Rave would be wrong then...According to RAVE it's one pulse every two revolutions on the Gems unit.
Certainly not unknown to be wrong!
eightinavee
Well-Known Member
No never that can't be.
Not often wrong,but in this case it must be - you only need look at the spokes of the cam sprocket to see why.Did have photos of both types somewhere,long time ago,cant remember.
That's what it says in the 1997 RAVE, i presume that would be GEMS. Number of pulses not mentioned in 1999 and on RAVE, which i presume will be THOR.
eightinavee
Well-Known Member
I must admit at this point that I copied and pasted part of that post from a SIDS.This is a systems information document that LR used in their tech support department,much more in depth than Rave or Topix,it even contains expected oscilloscope waveform traces for crank and cam sensors etc.
SIDS were never released to dealers or to the public...
You only need look at the spokes of the cam sprocket to see what kind of waveform you should get from them,either Gems or Motronic.
SIDS were never released to dealers or to the public...
You only need look at the spokes of the cam sprocket to see what kind of waveform you should get from them,either Gems or Motronic.
StuckAgainSteve
Well-Known Member
That really surprises me, crank sensors can only tell you TDC, the all important cam position from the cam sensor can provide both sets of information - so a failed crank sensor would not usually prevent an engine running because the same data can be calculated from the cam sensor - however if the cam sensor fails you don't know if your target cylinder is on the exhaust or compression stroke and therefore which cylinder to fire (or fuel) so the ECU may shut the engine down or (more likely) prevent it restarting. Perhaps it just switches to continuous injection and the wasted spark system allows the engine to run but badly?
An engine will usually run if the cam sensor fails while it's running as the ECU will calculate the cam timing (it keeps count!) - however once shut down it won't usually restart as there's now no trusted reference point for cam timing.
eightinavee
Well-Known Member
You have it the wrong way round ! The crank sensor is the all important one - it has no backup,so must work or the engine wont go.It is not just for TDC either,it is used for overall engine speed AND misfire detection.The ecu watches the gaps between crank sensor pulses to see if each individual firing event takes place.If the pulse gaps narrow it can tell a cylinder has fired,if the gaps widen it knows the crank has slowed down - then will log a misfire.If the misfire is persistant it will store a DTC.
That it runs without the cam sensor is normal,it just cant tell that cyl,s are on compression or exhaust strokes,so runs bank fired not sequential and disables the knock sensors - hence the OP's engine pinking.All his engines symptoms add up,scoping it would soon show whats going on....
