Managed to get voltage today not sure its going to help much. car was misfiring slightly in the capture. Channel B and C are still the current waveforms sorry forgot to change scale again. Channel A is the voltage of the suspect solenoid and channel D is the voltage of the good solenoid
Looking at it more closely I think I would have to use all 4 channels on voltage as it is clearly controlling the current flow by adjusting the voltage on both wires. Maybe this is how it is accurately producing the fault code. and it is running some sort of diagnostic strategy on every other turn on event??
Brilliant information thanks very much. Exactly what I needed to confirm solenoid failure. Where did you source this from?
On the down side we are struggling to get the locking tool so we may not be able to see the job through to the end
On the down side we are struggling to get the locking tool so we may not be able to see the job through to the end
That may not be such a bad thing - hold that thought.
Persuade your customer to let you supervise it in and out of the dealer for an admin fee. Present it to the dealer with your findings, scope traces, PDF from Martin, Print out of this thread if you wish...
You may find it impossible to find a dealer that will take that on, if you do then you have your customer covered every which way.
Technicians like you are thin on the ground and your customer may not find another in a lifetime !!!
You have diagnosed it - That is your job done !!
How many of your competitors in a 100 / 1000 mile radius can mimic that ???
Well done from me, you stuck to your guns and fought your corner with Passion, fact and Conviction
Hi,
I have update for this discussion.I recently worked on Fiat Punto Evo 1.4 turbo multi air 2012. year.Car had constant misfire and registered only one dtc,P0301 (1.cil. misfire).There was no compression on 1.cil. and I diagnose and after that replaced faulty multiair module.That was fix for this car.
What is interesting is fact that there is "V shape" in current waveform but module is faulty and it didn't opening intake valves at all because mechanical fault inside in it.I will post pictures of it later.
I agree and I know that ECM is looking for "V shape" in solenoid current of multiair module to store a dtc but even if there is one it doesn't mean that module is ok ! There is also a ECM control strategy where it is normal to not have a V shape in solenoid control current so diagnostic isn't simple for this application but it's not difficult also if you know what to do !
The mechanical fault inside module is that compression chamber for oil had stripped threads and because of that there couldn't be any oil pressure to open intake valves on 1.cil.
Update for this topic.Some problems with misfire in cold conditions were solved by only cleaning oil filter for multi-air module in cylinder head.It was very dirty in that cases...