Hi,

I have a Skoda Felicia 1.3 MPI 68HP from 1998, and it has done 121.000km now, When I first bought the car, a year ago, she would not start quickly, and there was no warm air in the cabin. The I changed the spark plugs to the correct ones, whis to spokes on the top where it fires, and I cleaned the comlete throttle body with brake cleaner, and sensor inside, and I replaced the complete thermostat house, with both the temperature sensor and the thermostat. And then it drove very fine and it started fast enough. Now it still starts fine, and it drives fine too, but she uses A LOT of petrol. I now drive MAX 360km on a full tank 42 litres. And she did not use so much before. So I put the tester on and it gave me these faults:

 

00513 Engine speed sender -G28, sporadic: Implausible signal

00522 Coolant temperature sender-G62, sporadic: Open short circuit to positive

00537 Lambda control, sporadic: Lower stop value

 

I have read a bit about others who also had same problems, and its likely a problem in the wiring going to the sensors. Does all three sensors wiring go from the same place to the sensors? And do you think the problem is the wiring to the sensors? The temperature sensor is almost new, so I dont think it is the sensor that is defect.

Have anyone tryied to have similar problmes, and what was the issue?

Hello, you can ignore the g28 fault for now, the engine won't run if this sensor is faulty.

for now I would change the engine coolant sensor and see what happens, the g62 will probably go away on its own when a new coolant sensor is fitted.

Ok. I see there is two types of sensors, one yellow ring that replaces the blue ring, and one green? 

When I changed the sensor first time, I did not see what color the ring had. I only replaced it with a yellow one. What do I do now?

 

And dont you think it is the wiring fault, because the sensor is not too old?

It's the lambda sensor which has the greatest affect on the fuelling, check it very closely for any breaks in it's wiring, if OK it might need replacing.

What about the temperature sensor?

Ok. 

I called Skoda yesterday to confirm what type of color my original temperature sensor had, and it was blue. So I bought a new temperature sensor, and a new lamda sensor, and replaced them both yesterday.

Then I cleared the error codes, from the ECU, and I turned it on. And the I drove it home, and when I arrived and it was at normal temperature, I unplugged the wires going into the temperature sensor while the car was runnning, but no difference! Then I plugged it in again, and then I tried with the lambda sensor wires the same, but no difference either.

I have read that if you unplug the wire while the car is running, it should react on it, and you should hear the motor going up/down in rpm's. But it did nothing at all.

Is it normal?

??

ok, i have now tested the car again after changing the lambda sensor and coolant temperature sensor, with our new vag tester, (vcds), and it shows me NO faults. So I believe I have succesfully cleared out for codes on the skoda. Now I only have to wait and see how much the car drives pr. litre petrol.

I have read that if you unplug the wire while the car is running, it should react on it, and you should hear the motor going up/down in rpm's. But it did nothing at all.

Is it normal?

It is not normal to do that as part of a diagnosis. There is no value in doing that unless you wrote the firmware of the ECU and you know there is a subroutine that reacts to such events. Generally ECUs 'learn' new operating conditions after a while, but never instantly. On the other hand, your car was running fine. I don't see the point of doing some 'test' that Skoda never recommended.

 

ok, i have now tested the car again ... with our new vag tester, (vcds), and it shows me NO faults.

From my knowledge VCDS testers are OBD-II compliant only. Skoda Felicia is compliant with OBD-I self- diagnostic and reporting capability that needs VAG-COM 311 or 409.