Hello,

I am Coming to you with a problem. Computer shows that the car has error: P0341 Camshaft Position Sensor (G40): Implausible Signal.

Things to consider:

• I understand that this can be because of incorrect timing, but mechanic that changed timing belt assured that timing has been set correctly.
• I have also swapped in new sensor and the error is still active.

My recent guess is that there is something wrong with the wiring to ECU unit so i measured the pins for connector.

 

With engine running my multimeter showed these readings on camshaft position sensor connector that goes to ECU without sensor connected:

Wire 1: 5V    Wire 2: 5v      Wire 3: 600ohms (Negative wire)

 

First of all it looks bad that 2 of the wires reads 5v since one of them should be signal wire (returning) So it shouldn't have any voltage at all?

Other thing that looks wrong is the 600 ohms for negative Wire 3. Is this too much resistance in this case?

 

I have read that also wires located close to glow plug wiring can get some interference from glow plug wires, so the signal will be incorrect again.

 

Any suggestions on what i could do next and if the behavior of the wires are correct or not?

 

 

 

Where is the other meter probe when you are measuring the 600 Ohms for pin 3; the other end of that wire at the ECU connector, or chassis/battery negative?

 

Depending on the way the output of the sensor works, there might be what's called a pull-up resistor on that input within the ECU, so it could be normal for the signal wire to read 5V when it's not being driven by the sensor output. I don't know if this is true in this case.

How long ago was the Cambelt changed?

Where is the other meter probe when you are measuring the 600 Ohms for pin 3; the other end of that wire at the ECU connector, or chassis/battery negative?

 

Depending on the way the output of the sensor works, there might be what's called a pull-up resistor on that input within the ECU, so it could be normal for the signal wire to read 5V when it's not being driven by the sensor output. I don't know if this is true in this case.

Other probe was connected to battery negative.

To this i understand what you mean, but i cant find any information regarding this yet :(

 

EDIT:

I luckily found some information regarding testing the wiring to the sensor.

In one sentence it mentiones: check to make sure you have 5V on each signal circuit going to each sensor to insure it has a signal circuit (Red lead to the sensor signal circuit, black lead to a good ground). If there is no 5 volts to the sensor, repair the wiring from the PCM to the sensor, or possible a bad PCM.

Read more at: https://www.obd-codes.com/p0344

 

According to this 5V at signal wire is correct and wiring should be okay. Then what else could cause this behavior?

Edited 20 December, 20169 yr by Isitme

How long ago was the Cambelt changed?

The cambelt was changed maybe a week ago. It showed same error before the cambelt change.

 

How about the glowplug wires interfering with the signal from cam sensor? I see that both, wires from sensor and wires for glow plugs are put together in one wiring loom.

 

*Sorry for double post. I have now learned how to reply using multiple quotes :D

Edited 20 December, 20169 yr by Isitme

At lunchtime I will compare measurements on my car.  It's a completely different engine/ECU, but the sensing technology and number of pins on the sensor is the same (I think), so comparison may be useful.

The 5V on pin 1 and pin 2 is the same on my car.  (And matches the info in your edit, above, I've just seen).

 

I don't have 600 Ohms from pin 3 to chassis /battery negative though, more like zero.  However, on my car, the pin 3 wiring joins a few other wires on a rail called 'earth connection in engine wiring harness'. 

 

I think when I looked at what I think may be the wiring for your engine, pin 3 went directly and only to an ECU pin, so you really need to try to measure to that point, and see if the 600 Ohms disappears, as it might be inside the ECU, and intentional.

 

If you can tell me the year of manufacture, and engine code of your car, I can check more carefully what the wiring is from pin 3.

The 5V on pin 1 and pin 2 is the same on my car.  (And matches the info in your edit, above, I've just seen).

 

I don't have 600 Ohms from pin 3 to chassis /battery negative though, more like zero.  However, on my car, the pin 3 wiring joins a few other wires on a rail called 'earth connection in engine wiring harness'. 

 

I think when I looked at what I think may be the wiring for your engine, pin 3 went directly and only to an ECU pin, so you really need to try to measure to that point, and see if the 600 Ohms disappears, as it might be inside the ECU, and intentional.

 

If you can tell me the year of manufacture, and engine code of your car, I can check more carefully what the wiring is from pin 3.

Thanks for your input and confirmation.

 

The ECU of my car is quite hard to reach since it is located under cover (Don't know how it is called, but near windshield cleaner motors?)

 

The year is 2007 and engine code should be BXE. Also could you share with me where you find such wiring diagrams? 

Pin 3 seems to go to pin 12 of a 60-way connector at the engine ECU, brown/green wire.

Info source is paid-for downloads from erWin Skoda. (Copyrighted, so don't ask me to share them)

Pin 3 seems to go to pin 12 of a 60-way connector at the engine ECU, brown/green wire.

Info source is paid-for downloads from erWin Skoda. (Copyrighted, so don't ask me to share them)

Thank you for your help. If i will get the opportinity and help with this i will try to check the resistance for the wire at ECU to connector. I am a new owner and not yet comfortable on doing such things on my own. (Removing parts)

 

In addition tomorrow i will bring my car to skoda service for checking the cooling since the heater matrix sometimes blows hot sometimes cold and in addition will try to address this issue with the sensor. I hope i can come back with some explenation and reason to this error.

Pin 3 seems to go to pin 12 of a 60-way connector at the engine ECU, brown/green wire.

Info source is paid-for downloads from erWin Skoda. (Copyrighted, so don't ask me to share them)

Hello, I finally was able to check the wires.

I found some damaged wires and one of the sensor wires was burnt indicating some additional current flowing in the circuit. After soldering in new wires to replace damaged ones i was also able to reach the ECU.

When locating the necessary pins i measured 0.5 resistance for all 3 pins to the sensor connector, so that means the wires should be good.

 

After connecting everything back and laying the wiring as far from other wires as possible same error still shows up P0341 - Camshaft Position Sensor (G40): Implausible Signal.

 

So considering that the sensor in new and this same error persists since purchasing it i assume it is not the sensors fault.

 

So i have only one more idea to try - check starters wiring and ground, but for this i have to find another time to test.

 

So i hope to get some other ideas i could try to resolve this issue?

Today i confirmed my consern about the sensor itself.

I thought that after putting the new sensor in the wires were still in bad condition and that would have burned the sensor causing it to show incorrect signal.

So today i checked the sensor in friends car replacing his sensor with mine and he got the same issue using my sensor, so that is good news for me.

 

I also checked the resistance for ground from battery to connector and it now showed 80 ohms through computer (Before it was 600ohm).

 

Next step is to purchase new sensor again and test it now after all the wiring loom has been fixed and reinsulated completely.

 

I will post my results after i get to install the new sensor.

 

If that will be the case i hope that this topic will Alert people with similar sensor problems to check wires for any damage first, before purchasing expensive sensor only to burn it again. If the last sensor god damaged, THERE WAS A REASON FOR IT (Usually).

 

So, I have managed to FIX my issue with this sensor finally!

 

In previous post i mentioned that i will purchase new sensor since i thought both of my previous ones had been burned because of the bad wiring that i found opening the loom.

The new sensor that i purchased was DELPHI (Same as first one i purchased) Showed as a good price and good manufacturer, also compatible with my engine code.

 

To my surprise it didn't work. Same Issue - Implausible signal. And that got me thinking that this sensor brand is at fault.

 

Thanks to my curiosity i tested the resistance from ground to signal wire which was almost identical across all 3 sensors (~650 ohms, also be careful - the sensor seems to have built in diode so the power flows only in one direction. I was also not able to measure resistance with normal resistance setting. Only the continuity test worked for me), which made me believe that my original sensor could be in working state after all.

 

And yes! It was working with my original sensor that has probably been in the car since it was manufactured.

(I assumed that original sensor was dead because it showed No signal, and swapping a new one showed implausible signal, without any additional steps done.)

 

Moral to the story - Test everything you can and start from the beginning of the problem and not the end!

 

In short the steps for a fix:

1. Check your wires for ground and voltage. Ground from Battery to the connector cannot be in 100s of ohms. Even going through the ECU.
2. Because my resistance from battery to connector was 600 ohms i opened all wiring loom and found multiple corrosion marks and burning marks on the wires. Be sure to Check all damaged wire since it can appear only small punctuation which in my case was close to a meter of burned black wires that i had to swap with a good ones. (The wire from outside looked perfect)
3. And try to test the original sensor after fixing the wires.
4. Oh, and do not purchase DELPHI sensors. 2 of them Were malfunctioning for me from different suppliers. I am now left with 2 perfectly new sensors that are not working correctly and are not taken back from supplier since i have put them in my car and damaged them myself.

I hope that this can be useful for someone else that faces similar issues.

And big thanks to Wino for extensive help!