Technical Rpm engine counter marks 1000 rpm more

[MKUser]

Hi, I've got suddenly an issue in my RPM engine counter.
It marks at least a thousand more than the real RPM.
When you start, without accelerating, it marks 2000 rpm.
Accelerarting it marks 3000 rpm when we are at 2000 rpm really.
The engine goes well.It sounds ok...
Does anybody know what could be the problem

 

[Communicator]

Hi, I've got suddenly an issue in my RPM engine counter.
It marks at least a thousand more than the real RPM.
When you start, without accelerating, it marks 2000 rpm.
Accelerarting it marks 3000 rpm when we are at 2000 rpm really.
The engine goes well.It sounds ok...
Does anybody know what could be the problem

You have not mentioned the model of your vehicle, but fron the 2002 introduction of the x244 model, the rpm indication has been via an electronically driven stepper moter, with the signal source being the crankshaft position sensor. As engine runs OK the sensor must be OK. Most probable cause is a failure of the instrument electronics.

 

[MKUser]

You have not mentioned the model of your vehicle, but fron the 2002 introduction of the x244 model, the rpm indication has been via an electronically driven stepper moter, with the signal source being the crankshaft position sensor. As engine runs OK the sensor must be OK. Most probable cause is a failure of the instrument electronics.

My model is from 2003, x244 2.8 jtd 128 cv.
Thanks for your answer.
It would be great knowing more about these instrument electronics problem...

 

[Communicator]

My model is from 2003, x244 2.8 jtd 128 cv.
Thanks for your answer.
It would be great knowing more about these instrument electronics problem...

I also have a 2.8jtd. I am not aware of any detailed published data concerning the instrument panel. Available diagrams only show the external connections in detail. See attached specimen which is based on Fiat eLearn for the x244. If you were in UK I would suggest the company "Cartronix" as possible repairers. You should be able to find someone closer to you.

 

[MKUser]

You have not mentioned the model of your vehicle, but fron the 2002 introduction of the x244 model, the rpm indication has been via an electronically driven stepper moter, with the signal source being the crankshaft position sensor. As engine runs OK the sensor must be OK. Most probable cause is a failure of the instrument electronics.

Do you think crankshaft position sensor replacement could be a solution ??
Thanks

 

[Communicator]

Do you think crankshaft position sensor replacement could be a solution ??
Thanks

No! As you reported that engine is running OK. Engine totally dependant on this sensor once started.

From your original post the rpm indicator has failed to returnt to zero. You may be lucky and get an easy fix by removing F53 in LHS fuse panel, and replacing after several minutes. This fuse in the only 12V supply shown on the rpm diagram, but my notes taken from handbook and diagrams, only mention illumination. My notes could be wrong.

I have a deja vue feeling about your fault, but I cannot remember as to where I have previously read of this problem. Perhaps an internet search would reveal something.

 

[MKUser]

Here's the problem. It marks 900 rpm with he engine off, even without the contact key...

 

[rayc]

Here's the problem. It marks 900 rpm with he engine off, even without the contact key...
View attachment 462948

Any chance that the needle has moved on its shaft i.e. it is not zeroing at the correct spot.

 

[Communicator]

You written decription was clear. If pulling the fuse does not work, see this this new post by @Anthony489 . While the post applies to sticking needles on the X250 model, access on the X244 is similar. Anthony describes pulling the needles off their spindles for accesss to the stepping motors. I would not try to force the needle back to the correct zero position, but pulling just the rpm needle, and replacing it at the correct position may be a cheap fix, and rather akin to aligning the hands of a clock. However if there is a fault in the electronics, the problem may reoccur.

 

[Anthony489]

Hi

See my guide uploaded today about sticking instrument needles - it is in the guides section of this website

Ducato X250 Sticky Needle Repair

How to repair stuck dashboard instruments

www.fiatforum.com

Your problem is likely to be due to the stepper motor mechanism sticking

For this simple repair it is not necessary to remove the needle and reposition it. The repair involves gently moving the needle up and down a few times, then setting it to zero.

Needle removal is only necessary if you want to replace the stepper motor.