[Noony]

I have a Kia Carens 2.0 crdi 2011, it has 170 000 km, recently it has hard start with long cranking, Cranks normally till battery dies sometimes but very hard to Start, even with quick start spray, once started the car runs like there were no problem at all, on the scan tool I have one fault: "crankshaft position sensor performance range/circuit", I decided to check the sensor circuit (three ends on the connector: ground, reference, signal), while inspecting the circuit the reference wire showed only around 2.5V, I know that the standard for sensors is 5V or 12V, the wires of the reference have no short and the problem should be with the ECU.
I want to simulate 5 or 12V voltage to the reference and see if the problem disappear to confirm its the faulty ECU, but I don't know what is the voltage the reference wire on this car.
So my questions are:
1. can any one tell me the voltage or have a diagram to this car where I can find it please.
2. If it is confirmed faulty ECU, can it be repaired since it is only one wire voltage altered, or should it be replaced?
Thanks to all

 

[Gerard 2]

I'd be inclined to replaced the crank sensor with an OEM unit if you can without diving into this too much. Hyundai/Kia crank sensors are a very common fail point. I ha a Santa fe with the 2.2 version of this motor. It definitely presented itself as a crank / no start and gave me warning signs when it got hot it would quit then it simply would not start and no activity on the tacho when cranked either. Instantly fired up with new sensor.

I'll be back after I get on my other PC and check the manuals

 

[Gerard 2]

Was it P0336

 

[Noony]

Mine didn't have a hard start when hot, it is unpredictable at all, and with the new sensor on the same problem persisted, the old one was not faulty and its resistance was ok (1200 Ohm), I read that the problem can be a short on the wire or faulty ecu voltage regulator responsible for this wire.

 

[Gerard 2]

while inspecting the circuit the reference wire showed only around 2.5V,

I think this is correct. I'm just flicking between other models because what I'm reading for the Carens looks suspicious and could be wrong. They mention 0.6 Volts but same motor in a sportage 2.4-2.6V

 

[Noony]

The scanner didn't throw the code but the message "crankshaft position sensor performance range/circuit"

 

[Noony]

same motor in a sportage 2.4-2.6V

So this voltage is not faulty, it's within the range.

 

[Gerard 2]

Mine didn't have a hard start when hot, it is unpredictable at all, and with the new sensor on the same problem persisted, the old one was not faulty and its resistance was ok (1200 Ohm), I read that the problem can be a short on the wire or faulty ecu voltage regulator responsible for this wire.

Information worth including on original post. I've also read of people using non OEM sensors for replacements and still having issues too.

Here's the resistance Kia quotes. I'll upload what I have so you can work through it. This will be Eurpoe market but should be relevant , just a question whether or not it matches your build

 

[Gerard 2]

This is what I'm unsure is correct for Carens D4EA 2011

 

[Gerard 2]

So this voltage is not faulty, it's within the range.

Can't be sure to be honest

 

[Noony]

Ok this is the scanner report, and in fact the replacement sensor was not OEM, because I didn't find it in my town, and as I was busy I bought that one. But the problem persisted.

 

[Noony]

It is a D4EA engine on this car, yes.

 

[Gerard 2]

This was for a Sportage of course this is coming from the ECU

 

[Noony]

Ok, exactly, there no signal reference as I thought, like mine there is a signal + (present on multimeter 2.5V), and a signal - (also present -2.5V) with the ground, so this is confusing now for me, can an oscilloscope help in this situation?

 

[Gerard 2]

Ok, exactly, there no signal reference as I thought, like mine there is a signal + (present on multimeter 2.5V), and a signal - (also present -2.5V) with the ground, so this is confusing now for me, can an oscilloscope help in this situation?

Well what you see on one is same for both so that's good news I guess, I did no post the other image . yes I agree I am not trusting the 0.6V at this stage either. What brand sensor did you put in and what resistance was on the old and new?
How accurate is your meter? Is it something decent FLUKE/Agilent etc or something really cheap

 

[Gerard 2]

can an oscilloscope help in this situation?

Probably, I don't have one , never tried but the wave form could give some clues, I'll see if they give that data. I was about to dive into some hyundais and see what they quote on those sensors

 

[Gerard 2]

you asked for it, all yours

 

[Noony]

The resistance on the both sensors was arround 1010 Ohm with good multimeter Mastech my-64, i use it always to measure resistors values for circuits use and it is very accurate to the value noted on resistors (to note the measurement was taken @~30°c not @20°c as in the manual you shared and resistance get bigger the warmer the climat is), for the brand

at the store he sais the brand is a good alternative to the original

 

[Noony]

Thanks a lot for the waveforms and your time sir, I will check for it tomorrow.

 

[Gerard 2]

But wait there's more. You're welcome