Got a problem with my car and could do with some help.

The car is a 2010 Ford KA(RU8) Studio 1242cc Petrol. It has been in the family since new so I know the complete service history. It has only done 15,500 miles to date and has not been abused. Apart from a few minor things it has been totally reliable.

About 3 weeks ago I went for a run and all was OK. A week later when I tried to start the engine it cranked OK but would not start. When I pushed the accelerator to the floor whilst cranking it chugged a bit but then started. The engine idled OK and at the correct speed but the amber EOBD/Injection system light was on and the rev counter was completely dead.

I turned the engine off and went off to read the Owner’s Manual which said it was OK to drive as long as the engine was not stressed. I thought it might be a damp problem (the car is kept outside and it had been raining hard) so I went for a drive of about 10 miles to see if the problem would clear once everything warmed up, but no joy. The engine ran smoothly and idled OK but it was down on power.

I did lots of research (Haynes manual and the internet) and the symptoms seemed to point to the Crank Position Sensor. I physically checked the CPS and it looked fine – No damage and wiring all OK. I bought an inexpensive OBD2 Code Reader and the only logged fault code was P0335 “Generic, Current, Crankshaft Position Sensor A Circuit”. So that seemed to confirm the cause of the problem.

Looking on the internet for a new CPS there are a huge number of parts available from different manufacturers ranging in price from £15 (Ridex) to £28 (Magneti Marelli) to £65 (“Genuine Part” from Ford) and others up to almost £100!!

So, a few questions to those who may have seen this type of problem before:

1) With the information given, does my diagnosis sound correct?

2) Why would the sensor fail at such a low mileage?

3) What replacement part should I buy? (I will do the work myself)

Thanks, George.

 

Your diagnosis does sound correct.

Be careful with the acronym on these though.  CPS is used for the camshaft position sensor in the trade.  CKP is used for the crank position sensor.

Mileage is irrelevant once a car reaches around 10 years old.  Things to start to break.

If you have a multimeter I would recommend checking the wiring with that rather than just visually.

Regarding parts choice, I'd avoid Ridex (own brand) but would use a decent branded part such as the Magnetti one.  

Once the crank sensor is replaced on the Ka, it may need to be reset using a procedure that Ian posted in another thread on here earlier today.

Hi Tom, and thanks for the quick reply!

CPS/CKP - Point noted.

I have a decent multimeter so can do some checks. Am I looking for wiring continuity from the plug at the CKP end to the connections at the ECU? I've heard that the ECU is a bit tricky to access on the KA. Also, I think some/most multimeters measure continuity/resistance by passing a small current, and I wouldn't want to fry the ECU!!

I mentioned the Magneti Marelli CKP as I believe the KA engine is basically a Fiat so it seemed likely that parts from an Italian company would be used as OE. Looks like that's the way to go then.

I'd already read about the learning procedure but thanks for the link to the post here - Good to have handy for reference. It will be the first time my little engine has been over 6,000rpm - I hope it's not too much of a shock!

George.

15 minutes ago, George L said:

It will be the first time my little engine has been over 6,000rpm - I hope it's not too much of a shock!

Before you do.........      is the timing belt in good condition ?

OK. Getting on with the job now. But cannot figure out how to disconnect the pesky connector to the sensor.

I'm guessing it has something to do with the yellow part but I cannot get it off and don't want to break anything.

Help!!

George.

 

I wouldn't get genuine Ford because that would be after paying commission to Fiat for the genuine Fiat part.

Search parts suitable for Fiat 500 with same engine, it's the same car

Definitely change the sensor

Use a small flat blade screwdriver.