Technical phonic wheel
- Thread starter discus
- Start date
Currently reading:
Technical phonic wheel
phonic wheel relates to the TDC sensor. ive no idea about resetting it though, maybe it means check the gap between the wheel and the sensor?
- Joined
- Feb 16, 2005
- Messages
- 5,983
- Points
- 988
This is old and probably no use to the OP, but I haven't seen it mentioned in the cinq section yet, so it may prove useful too some people.
If you replace the crank sensor or mess with it or the crank pulley, you should teach the ecu the new sensor and settings. This is called phonic wheel learn.
This is necessary as the sensor is inductive and measures a changed of magnetism cause by the crank ring turning, and is very sensitive.
To perform it, make sure the gap is ok, 0.8mm -> 1.5mm from the top of the notch to the face of the sensor.
Rest the ECU by disconnecting for 15 mins. Start it and let it get to temperature by idling (wait for the fan), then rev hard (above 5000rpm) and lift off immediately until it idles again. Do this 3 times and turn of the engine.
Job done.
Kristian
If you replace the crank sensor or mess with it or the crank pulley, you should teach the ecu the new sensor and settings. This is called phonic wheel learn.
This is necessary as the sensor is inductive and measures a changed of magnetism cause by the crank ring turning, and is very sensitive.
To perform it, make sure the gap is ok, 0.8mm -> 1.5mm from the top of the notch to the face of the sensor.
Rest the ECU by disconnecting for 15 mins. Start it and let it get to temperature by idling (wait for the fan), then rev hard (above 5000rpm) and lift off immediately until it idles again. Do this 3 times and turn of the engine.
Job done.
Kristian
Due to slight manufacturing tolerances (crank pulley is often a very slight oval shape) the gap between position sensor & pulley is critical it is necessary for the ECU to learn the shape of the pulley....thus 'phonic wheel learn'.
craiggasman
New member
Hi,
Just disconnect the battery.
As a side note the term "phonic wheel" comes from when similar wheels and pickups were used to produce audio tones in electrical test equipment and musical instruments. Hammond electric organs used this technique. in test equipment you could have two pickups and by adjusting the position releative to each other generate two outputs of differing phase.
Robert G8RPI.
Just disconnect the battery.
As a side note the term "phonic wheel" comes from when similar wheels and pickups were used to produce audio tones in electrical test equipment and musical instruments. Hammond electric organs used this technique. in test equipment you could have two pickups and by adjusting the position releative to each other generate two outputs of differing phase.
Robert G8RPI.
craiggasman
New member
hi thanks i'm just checking been told by someone else on here that you have to hold the revs over 5000 for 3 seconds is this right or do you just lift off after 5000
MultiRacer
Member
I think first you let the cooling fan kick in twice, at least thats what had to be done to reset the phonic wheel on the Multipla.
When I reset mine after fitting a new ECU I just let it idle up to temperature (fan cut in) and then went for it
I had never heard of Phonic wheel reset and was pretty amazed when it cured my flashing light problem
I had never heard of Phonic wheel reset and was pretty amazed when it cured my flashing light problem
craiggasman
New member
hi thanks i'm just checking been told by someone else on here that you have to hold the revs over 5000 for 3 seconds is this right or do you just lift off after 5000
well i did try it both ways:bang: to make sure i had done it the right way but didn't fix my car
new camshaft sensor and reset light and hasn't come since and finger crossed it won't:slayer:CrippsCorner
New member
Hello, appreciate this is an old thread, but after some AI chat after problems from a timing chain replacement on a 500L this 'phonic wheel learn' popped up. Problem is, engine won't start... so how can I run this?
500l from 1968–1972
Or modern 500L very different
Which engine
Assuming it's a modern 500L and a diesel
A new thread here might return more and better results https://www.fiatforum.com/forums/500l.234/
Phonic relearn does not prevent t from starting
You can not perform a phonic relearn unless the car is running, revs freely and up to temperature
If it was running fine before the timing chain change, It would suggest something something went wrong or got damaged during it replacement
I assume the reason you now have a phonics relean not done code
Is the adaptive memory has been reset with a scan tool, prior to read the codes
CrippsCorner
New member
Thanks for replying. The car is a 2015 500L 0.9ltr TwinAir.
Unfortunately we've had real issues with the absolute cowboy doing the work... we do not really want him working on the car any further, however, he did send a message saying:
The adaptations need doing
And then testing
I thought the phonic wheel learn could be part of the adaptions, but is this purely ECU related? Should point out, we also had the crankshaft sensor replaced at the same time as this was throwing an error code, however this has now cleared (there are no 'current' faults on the car at all, according to the scanner tool)
Unfortunately we've had real issues with the absolute cowboy doing the work... we do not really want him working on the car any further, however, he did send a message saying:
The adaptations need doing
And then testing
I thought the phonic wheel learn could be part of the adaptions, but is this purely ECU related? Should point out, we also had the crankshaft sensor replaced at the same time as this was throwing an error code, however this has now cleared (there are no 'current' faults on the car at all, according to the scanner tool)
Phonics relearn
And all adaptive memory cleared
Will not stop the car from starting
It will just be at its none optimal safe settings, but it will always start
How long has it been out of commission, if left for too long the twinair block drains of oil, causing no oil pressure to operate the valves and no compression, oil will need priming again
When turning over does it sound right
Or faster than normal weeeeeeeeeeeeeeee instead of whir whir whir
I only work on older cars so my knowledge of the twinair is limited, last Cinquecento / Seicento was 15 years age
If it's got compression, you have to go back to basics, is the rev counter moving when cranking, is there a spark
Does the key immo come on and go out
Does the oil and battery lights come on when you turn the ignition on
Does the battery stay on while cranking
And all adaptive memory cleared
Will not stop the car from starting
It will just be at its none optimal safe settings, but it will always start
How long has it been out of commission, if left for too long the twinair block drains of oil, causing no oil pressure to operate the valves and no compression, oil will need priming again
When turning over does it sound right
Or faster than normal weeeeeeeeeeeeeeee instead of whir whir whir
I only work on older cars so my knowledge of the twinair is limited, last Cinquecento / Seicento was 15 years age
If it's got compression, you have to go back to basics, is the rev counter moving when cranking, is there a spark
Does the key immo come on and go out
Does the oil and battery lights come on when you turn the ignition on
Does the battery stay on while cranking
CrippsCorner
New member
Lot to go on there, thanks.
I'll try and grab a video tomorrow as I'm no expert.
This Sunday it would have been 3 months off the road... however, timing chain was done around 10 days ago, with new oil and filter put it afterwards.
Revs almost get to 1,000RPM but not stable at all, dips to half that regularly. If I keep key turned it keeps trying for about 20 seconds, then EBD error appears on dash, car dies and EML comes on - Scanned for this and it says 'Lengthy Startup By Key - Signal Invalid' but I'm guessing that's just because you're not meant to keep a key turned for that long!
I think all the proper lights come on as they should. Surely the battery is on whilst cranking? I can get a multimeter on it. I did note before testing the battery was sitting at 12.65v after 24hrs on a trickle... but after it had dropped to 11.5v and that's including a fully charged jump starter being connected the whole time too.
Thanks for your help.
I'll try and grab a video tomorrow as I'm no expert.
This Sunday it would have been 3 months off the road... however, timing chain was done around 10 days ago, with new oil and filter put it afterwards.
Revs almost get to 1,000RPM but not stable at all, dips to half that regularly. If I keep key turned it keeps trying for about 20 seconds, then EBD error appears on dash, car dies and EML comes on - Scanned for this and it says 'Lengthy Startup By Key - Signal Invalid' but I'm guessing that's just because you're not meant to keep a key turned for that long!
I think all the proper lights come on as they should. Surely the battery is on whilst cranking? I can get a multimeter on it. I did note before testing the battery was sitting at 12.65v after 24hrs on a trickle... but after it had dropped to 11.5v and that's including a fully charged jump starter being connected the whole time too.
Thanks for your help.
