Technical Dreaded P0335 Crank Sensor fault code

[Dave2wheels]

Dreaded P0335 Crank Sensor fault code
Panda 4x4 2005 (1.2 8v?). only done 6500 miles as is on a small island, owned since new in the family so no previous history of issues

I have been reading many posts on this, it has been into the garage for diagnosis so I will give you my story and updates

The issue
Car cut out when slowing down, went into limp mode
had the pump the throttle pedal quite hard to get engine started and it moving again
next day the rev same issues and the rev counter stopped working

Diagnosis
Went into garage where it was diagnosed with fault code P0335 he fitted a new battery as it was in poor condition (and you can imagine it took a hefty toll to start it each time), and he cleared the fault code....

Running nice and warm all ok, lovely.

Issue returns
Next day cold start, started fine, drove 100 yards up the road and in went into limp mode, EM light on, rev counter stopped working
....
Phoned garage waiting to discuss and decide on next actions....

 

[koalar]

Dreaded P0335 Crank Sensor fault code
Panda 4x4 2005 (1.2 8v?). only done 6500 miles as is on a small island, owned since new in the family so no previous history of issues

I have been reading many posts on this, it has been into the garage for diagnosis so I will give you my story and updates

The issue
Car cut out when slowing down, went into limp mode
had the pump the throttle pedal quite hard to get engine started and it moving again
next day the rev same issues and the rev counter stopped working

Diagnosis
Went into garage where it was diagnosed with fault code P0335 he fitted a new battery as it was in poor condition (and you can imagine it took a hefty toll to start it each time), and he cleared the fault code....

Running nice and warm all ok, lovely.

Issue returns
Next day cold start, started fine, drove 100 yards up the road and in went into limp mode, EM light on, rev counter stopped working
....
Phoned garage waiting to discuss and decide on next actions....

the Crank sensor could be a red herring.

a slipping alternator belt or faulty injector and similar can also throw up this code as the engine twitches it thinks its reading it wrong


I too have had the problem of the engine dying and gauges failing (in my case it was the fuel gauge) mine was due to a fault battery


As yours was fixed temporarily I would be looking at testing the charging system and checking the earth strap. Its easy to eliminate the earth strap by making a temporary one out a jump lead (battery negative to somewhere on the gearbox)

 

[MrMagoo]

I don't understand why changing the battery and clearing the fault code would fix the fault. A competent garage would monitor that and other sensors and do the appropriate physical checks. I will say I have experienced this fault on older Renault's and Alfa's and it was the crank sensor.

 

[varesecrazy]

Does it have the CAM sensor..?

If too early for a cam sensor..

A loss of signal from CRANK ROTATION means no rpm detected..

No fuel injected..no sparks

And a Rev counter showing zero

 

[DaveMcT]

The crank sensor will not raise a fault because the effect is just the same as switching off the engine.
Old alternators do all sorts of odd things. Check the system voltage is holding up and not going too high. Make sure yours turns freely - remove the aux belt and spin the shaft. Mine was partially seized up. I replaced it. A month late, the old one (left in garage) was rock solid.

 

[Dave2wheels]

Does it have the CAM sensor..?

If too early for a cam sensor..

A loss of signal from CRANK ROTATION means no rpm detected..

No fuel injected..no sparks

And a Rev counter showing zero

Yes I think this 2005 4x4 Panda does have a Cam sensor as well, otherwise what is that thing on the top cam belt housing? looks like a sensor but I need to get a manual to confirm

 

[Dave2wheels]

so the next plan of action is to get a new crank sensor but...

its been sitting in the garage and after reading previous posts on this, one of the key bits of info is the rev counter not working so it is worth looking at the connectors and wiring from other parts to ECU.
I don't think there isn't anything really technical about the rev counter other than taking pulses from the coil? so I suppose I put a multimeter and check there's a suitable input to read?

I did the cheap and quick application of WD40 and let the car dry out in the garage for a few days. New battery fully charged.

The next time it started I didn't have to do the one-legged pogo dance on the throttle, in fact I didn't touch the throttle pedal at all and it started.
The EM light is still on and the rev counter still is not working but the engine ran nicely...to the car garage and back comparatively without an issue, certainly did not cut out, and that is good
(didn't feel if it was any shorter on power as there's a 30mph limit on the island anyway!).

Somewhere there does seem to be a noise that I don't remember, it's subtle, more like in injector ticking but only when the revs pick up, or maybe I didn't pay as much attention when it was working properly

I'm really quite tempted to get an ODB diagnostic meter (EODB II or something like that), not just for this car, I noticed there were 2 on the Machine Mart website the Sealey is their best seller apparently (£102) think the other was a Clarke at £142, I'll get the links to these.

 

[Dave2wheels]

I don't understand why changing the battery and clearing the fault code would fix the fault. A competent garage would monitor that and other sensors and do the appropriate physical checks. I will say I have experienced this fault on older Renault's and Alfa's and it was the crank sensor.

It's true, I did tell the garage that the reason the battery was in such poor condition was that the car had serious difficulty starting so the battery had taken a hammering just to start (more than once) to get to the garage
The next day it was no joke to say I only got a hundred yards before it literally went bang with the EM light back on and engine cutting out
So if it will now start easily and run well without further issue it does make you wonder what the real problem is

 

[DaveMcT]

www.MultiECUscan.net will sort it out

Engines that dont have a cam sensor will not recognise a crank sensor fault. When there is no signal, the ECU simply thinks the engine is not turning so no code generated. When there are two sensors (crank and cam), it will detect the mismatch and raise a fault code.

 

[Dave2wheels]

the Crank sensor could be a red herring.

a slipping alternator belt or faulty injector and similar can also throw up this code as the engine twitches it thinks its reading it wrong


I too have had the problem of the engine dying and gauges failing (in my case it was the fuel gauge) mine was due to a fault battery


As yours was fixed temporarily I would be looking at testing the charging system and checking the earth strap. Its easy to eliminate the earth strap by making a temporary one out a jump lead (battery negative to somewhere on the gearbox)

missed the last bit you said first time around, yes its worth rigging up a new earth strap, I'll do that next, then I want to check the output to the rev counter which I am convinced will be fine at one end...

 

[koalar]

I didn't think they had a cam sensor until around 2009 but fiat tend to chop and change things around.

Assuming yours has a cam sensor and rev counter still displaying no REVs


The fault is likely to be the Crank senor or its wiring.

A code reader with live data should be able to read the sensor and confirm this.

 

[A3jeroen]

Would it get fuel without a cranksensor signal? I doubt it. Where does the rev counter get it's signal from?

gr J

 

[koalar]

Would it get fuel without a cranksensor signal? I doubt it. Where does the rev counter get it's signal from?

gr J

rpm sensor -> ECU ----can bus-> body computer -> instrument panel

 

[DaveMcT]

Would it get fuel without a crank sensor signal?

gr J

The ECU sends fuel and sparks when it sees the crank is turning.

 

[rmjbn1]

Our 2004 1.2 has just been diagnosed with fault code P0335 rpm sensor. Car has cable throttle and camshaft position sensor as well as crankshaft sensor.

Had it checked for codes after intermittent sudden stalling. Most frequently when slowing down or off throttle, but has happened at speed with engine hot too.

No misfire or rough running, engine abruptly stalls. Sometimes engine cuts back in and continues to run fine, sometimes car coasts to a halt.

Sometimes engine will turn over without firing from hot or cold, sometimes starts and runs normally.

Following above advice, I was planning to:

• charge the battery
• run a temporary earth with a jump lead from battery negative to gearbox
• check the timing belt hasn't slipped
• check the alternator is charging and not sticking / slipping belt
• check cylinder compression to confirm head gasket is OK
• test again

Is there anything else I should consider before replacing the crankshaft sensor, please?

 

[rmjbn1]

Some background:
Car bought October 2018 92k miles, no faults.
Spring 2019: new spark plugs (Champion RA7YC), throttle body removed and cleaned with brake cleaner & toothbrush as part of routine service
Now at 106k miles, been running fine, except for sluggish starting last winter as battery struggled with lack of use.

Friday: warm start after a short run turned over 5sec or so before firing. Engine stalled twice and started running again on journey home. Check engine light came on when stalled and off again when running.

Saturday: disconnected battery, removed TB, MAP, plugs and leads.
Cleaned TB with rag sprayed with brake cleaner. Tried & failed to prise IACV from TB. MAP was clean, sprayed with brake cleaner.
Plugs were clean, gaps slightly wide on plugs 1&3, regapped to 0.9mm (35thou).
Reassembled, connected battery, fired straight away but idled fast @2000rpm and unevenly for 1min. Engine check light stayed on.
Turned off, unplugged & reconnected MAP, IACV and TPS. Started fine and idled smoothly @800rpm, engine check light still on and has been on since.

Sunday: turned over without firing from cold, 2 attempts for 10+secs. Unplugged and reconnected MAP, car fired and ran normally. Set off on journey, ran fine for 30 miles on fast roads, stalled repeatedly when slowing down in town, difficult to restart. Stalled abruptly a few times on journey home, a couple of times at speed.

 

[koalar]

I'd try a different battery


opening the bonnet disconnecting something, reconnecting is giving the battery voltage time to bounce back



you could measure as you are cranking but its not that easy. Most meter are quite slow.


if it drops below about 8V its getting marginal

 

[DaveMcT]

Check the alternator as well. I changed a battery only to find the real problem was weak charging output

 

[koalar]

heres mine from 2017

https://www.fiatforum.com/panda/454287-1-1-cold-start-idle-problem.html

hard to start but turns over fine

revs drop at junctions and stalls

Fix was battery. Old MAP was put back in at a latter date

thanks to triballofts who put me on the right path

 

[rmjbn1]

Thanks chaps. I'd been wondering about the voltage since reading a few threads about P0335 on here, especially after my battery struggled so much last winter, sometimes turned slowly and failed to start, tripping the dash clock.

It's only a 40Ah battery, and getting old now. I was planning to replace it this winter anyway if the sluggish symptoms returned, so I guess now would be a good time, plus new earth lead just to rule it out.

I'll check the alternator is doing its job too. I have A/C so not too keen to change the alternator unless I have to.