Technical '06 Panda crank sensor issue.....

[milleplod]

....has got me stumped!!

Afternoon all.

Not been on here for ages as haven't had a Fiat with a problem....till now! My dear old mum's '06 plate Panda 1.2 Dynamic Dualogic has conked out, and we're struggling to sort it. The car's done only 15k miles from new and has been very well-serviced from day one. Last week, mum was coming back from bingo, turned from the main road onto her cul-de-sac and the engine died. It re-started straight away....died again a few hundred yards down the road, re-started and then kindly let her get home and park on the drive.

The next day, called for my usual morning cuppa, and then took the Panda out for a spin. It started immediately, let me get half a mile up the road and then almost died on me, but picked up again without me having to re-start. It did the same thing once more on the way back to mum's. Got thinking cap on....for a day or two....back to mum's, started straight away again but didn't even get to the end of the drive before dying.

Spoke to my mechanic mate who kindly turned out that evening - he suspected the crank position sensor, fitted a new one....fired up, but died almost immediately. Fitted a new, new one...in case the first one was duff...just the same. The next day, I fitted a cam position sensor (because it was easy!), but now it was a complete non-starter, turning over nice and fast (new battery 6m ago) but nothing at all. Fuel pump fine, and fuel is getting to the fuel rail.

Yesterday, I called out our breakdown cover. The guy plugged his code reader in, it came up with 'crank sensor not detected' - or similar - so he recovered it to aforementioned mate's place. He put his code reader on, and got (I think, doing this from memory) '0355 crank sensor', even though the car had the second new one fitted. So....he checked the plug and the visible wiring, no obvious problems (the car is like new under the bonnet, no grime/oil leaks at all), took the sensor out again, refitted it....still the same code.

He had noticed that the new sensor came with an O-ring in the box, the original one didn't have one fitted. Tried new sensor with/without, just in case....no difference.

Has anyone any ideas at all? ECU fault?? The next obvious step will be a visit to the local dealer (I don't think there's a Fiat specialist around here), and at their rates I can see mum's car heading for an early grave - its probably only worth a grand, so a day diagnosing at lord-knows-how-much-an-hour may see its demise!

Pete

 

[Goudrons]

P0335 is a crank sensor circuit malfunction.

I'd start with cleaning the connections between the looms connectors and ECU down the side of the battery.
Undo them and spray both sides with contact cleaner, let it dry a while and refit them.

Then perhaps scope the crank sensor through the ECU with a scan tool.
You should be able to see if it's reading a signal on just the starter motor as it should read the RPMs which comes from the sensor.

No joy with that, I would be tempted to trace the wires back to the ECU connector and test their continuity.

 

[milleplod]

Thanks for the reply. My mate did disconnect the 2 large multi-pin plugs at the side of the battery and gave them a clean. No joy. He put his multimeter over the crank sensor plug pins, it showed 3v.....the cam sensor one showed 5v - does that sound right, he thought 3v was a bit odd?

Pete

 

[Goudrons]

I'm not sure what the signal voltage should be, but most sensors take a 5v feed from the ECU, alter it somehow and return the altered signal back to the ECU.

So they tend to have a feed wire, a return wire and perhaps an earth, are the right wires being probed?

The 3v detected could be the circuit fault I suppose, but I'd want to look for a "good" reference from another, working car to be do certain.


Perhaps the next step would be to source and test the relevant 5V feed pin on the ECU (though I suspect that is shared with other sensors) and test that, then test the continuity of the loom.

It's not unheard of for looms to develop issues, the 1.1 model suffers a fault on one of the connectors to the ECU that involves the coils and injectors.
Perhaps a wiggle of the wires at the connectors while the other end is probed might show something up?


I did find this, worth a look as well.

 

[milleplod]

Thanks again.

The crank sensor plug only has 2 pins, one showed 0v, the other 3v. Cam sensor plug has 3 pins though, showing 5v, 5v and 0v. I think he'll be wiggling stuff tomorrow!

Pete

 

[koalar]

I am guessing here.

If a senor was fitted incorrectly in the past it might be worth checking there's no damage underneath and check the gap between the end of the sensor and wheel

 

[milleplod]

There's only one way to fit it, no adjustment, and its locked in place by one bolt. The new sensor was identical to the original one.

Pete

 

[koalar]

Thanks again.

The crank sensor plug only has 2 pins, one showed 0v, the other 3v. Cam sensor plug has 3 pins though, showing 5v, 5v and 0v. I think he'll be wiggling stuff tomorrow!

Pete

Strange 2 pin sensors create there own voltage. One side is 0V the other a sine wave when the engine is spinning


The three way cam is correct. 0v ground 5v supply and 5v signal when spinning the signal will chop down to 0v in a square wave when the engine is spinning.


Not sure why the crank isn't 0v and 0v unless Fiat does something odd.

 

[RDM1]

Hi there everyone i have a fiat panda 2011 dualogic milleplod same as yours and it did the exact same thing as yours it's now at 75000km i tried changing 2 crankshaft position sensors one used on a running car and the one before was a brand new Magnetti Marelli but both didn't work. I sent my ECU to someone that knows how to fix them, he cracked it open and tested it and even on the car and he said that there's no issue with it so now I'm at a loss to what i should do, i double checked all the connections even ground ones all is clean and firmly connected Ecu was closed properly again and seated in its place using Victor Reinz. Now one thing after becoming so desperate for 6 months without the car is that right now i was measuring the car's CPS voltage i noticed when putting the negative prob of the multimeter on the negative battery terminal and inserted the positive into both pins on the CPS i am getting 2v steady reading on both pins and got someone to crank the car for me there's no fluctuations or change at all it's a steady 2v.
Did someone find a solution for this issue? I'd be grateful if you could help me because someone told me that it's a dead ECU but i wanna be sure about it before throwing a big sum of money over it because the BCM is probably bad aswell as it was tempered with the previous owner but i got the car working.
One last thing i forgot to mention is that when i crank and it fail to start the next ignition opening causes the immobilizer to flash 3 times with the last time lasting longer than the others and yet when i crank the car refuses to start

 

[koalar]

This is a 5 year old thread that went dead

Let's start at the begining

If you look carefully at the RPM rev counter, does the needle move at all as you crank the car

What the history with the car and how it failed, fails to start on morning, cut out while running for example

What the rpm using a obdii scan reader

 

[RDM1]

This is a 5 year old thread that went dead

Let's start at the begining

If you look carefully at the RPM rev counter, does the needle move at all as you crank the car

What the history with the car and how it failed, fails to start on morning, cut out while running for example

What the rpm using a obdii scan reader

Alright so it all began about 6 months ago when i was driving normally just like any other day then after turning a sharp 90 degree corner i pressed the gas pedal to accelerate i got no response but the gearbox downshifted as it should i kept rolling with the car as there was a downhill after that for about 300m then the car jerked and turned off i was out of tools so the best i could do was takeout the negative terminal connector for a minute but the car cranked but didn't start so i took it out and waited for about 5 minutes this time i placed the connector and the car fired right up i had a trip of about 1km no issues at all while coming back home after about 500m the car went out while driving 3 times but somehow I managed to make it start until i made it back home then upon hooking it up my ancel x5 i got p0335 so i immediately ordered a cps Magneti Marelli brand new installed it and went for a ride thinking that it was over but unfortunately almost at the same place the car died out but this time it fired back up wasn't refusing to start for about 6 times until i managed to bring it back home and after that it has been always like that going on and off as it pleases whenever it likes even when the ECU was worked with.
As for your question about rpm feedback when it was still doing this issue when i was swapping with the CPS's i was getting RPM sometimes a little bit delayed but the car would start sometimes whereas now it refuses to start at all no rpm when cranking and the ECU won't read RPM value while reading its data on the Ancel x5.
Thank you for assisting me

 

[koalar]

Thanks for the feedback leave it with me a few minuites need to find one of my old videos

 

[koalar]

"i was getting RPM sometimes a little bit delayed"

Like this

 

[RDM1]

No wish i had a video of this but at first there was nothing when cranking then about a second the RPM jumps to meet the 600 rpm of the starter without starting but now there's no RPM at all and no start

 

[RDM1]

That's how it's been behaving ever since it stopped starting at all

 

[koalar]

Right that's great

Looks to me like the oil and battery warning light aren't as they should let me check

 

[koalar]

Isn't your oil light here

It should be on at ignition on position and come back on when the engine isn't cranking

I am begining to think there is a bad ground

 

[koalar]

Do you have a multimeter to measure voltage or a test light

 

[koalar]

I have slowed your video down

The oil light comes on for a brief fraction of a second

But goes off before the engine cranks

This is not correct

It likely the engine block isn't at 0V

Wrong ground reference will mess with the sensors

Need to do a voltage drop test under load to confirm

Does it sometimes fail to turn over (crank) aswell

 

[RDM1]

No it has cranked for a lot of times and by a lot i mean a LOT for the last six months and even when the battery was very weak but still cranking it was still perfectly normal as for the grounds i checked most of them but I'm not sure if there is any that i missed in some secluded area. I checked one from the gearbox to the chassis that was disconnected when i received the car it's still firmly seated as i fixed it and those located on the ecu that are 2 fixed by a 5mm hex are tight aswell can't remember if any other but if you do know of any please do tell but i won't be able to try them for the upcoming 3 days as we have some rain coming and i don't have a place inside to tinker and disassemble the car but would gladly throw an eye if it's an easy place