1.4 TSI CZDA (2016) P0300 / P0301..04

Hello,
I'm looking for tips on diagnosis, and I have VCDS and VCP available.
1.4 TSI CZDA 4x4 DSG in a Yeti manufactured in May 2016.
Since kilometer reading 7,000, the following issue has repeatedly occurred:
The engine has been warmed up (e.g., on the highway or in heavy traffic).
- The engine is switched off (for a few minutes or a maximum of 1 hour).
- Afterwards, a city drive. After a few minutes at a traffic light, the check engine light (MIL) started flashing.
- This usually only happens once.
Stored error code P0300: Misfire detected in all cylinders, intermittent.
and then P0301/P0304, which indicates misfires in cylinder 1 and 4, or P0302/P0303, which indicates misfires in cylinder 2 and 3.
Skoda has been working on it for a year, the warranty has now expired, and there are major problems with the warranty.
Completed:
- Skoda checklist completed (meaning all sensors, etc. have been tested).
- Cleaning of the valve and combustion chamber, inspection via endoscope (no findings).
- New spark plugs.
- New fuel injectors (latest version)
- Software update to the new version.

The problem remains.
What I noticed is that I found oil on the throttle body housing. The dealer says it's normal or could be due to the repair work, as parts like the air duct were disconnected.

It's important to note that the engine is running perfectly verschandeln and flawlessly. Since all the modifications and the new fuel injectors were installed, the fuel consumption has decreased significantly. When the MKL (Malfunction Indicator Lamp) is flashing and you gently increase the engine speed, it runs perfectly smoothly.

The workshop was never able to reproduce the error, but it typically occurs for me every four weeks, although I can force it to happen (see the sequence above).
Over the weekend, I successfully logged the error for the first time, but I probably didn't include the correct parameters (crankshaft speed, lambda sensor values). What's observed is that when the check engine light is flashing, the engine is experiencing approximately 70 misfires in total over a period of about 12 seconds in the affected cylinders.

Before I start logging any more data, I'm looking for input on which values would actually be helpful. The dealer supposedly performed various test drives and transferred the data to Skoda. Since the error never occurred for him, that didn't help much.
Ideas?

Please initiate a full system scan.

Best regards, Rainer.

It would indeed have been smarter to do it directly .
Ignore the errors in CEM, DSG, etc. The DSG error is caused by the encoded extended speed limiter, while the rest of the errors are related to doors that opened and closed at the wrong times.
Autoscan and log data from the time the check engine light was blinking are now included.
Thank you!

Hi,

Quote:

What I've noticed is that I found oil on the throttle body housing.

Since the motor vents into the intake manifold, it's perfectly normal as long as the seepage remains inside and doesn't leak out.

There are several possible causes for detected misfires.
- Engine compression questionable (burnt/broken valves, valves not sealing properly, etc.).
- The engine is running too rich (check the lambda value at full throttle). If it's too rich, there might be a leak in the intake air system.
- The engine is running too lean (check the lambda value at full throttle). If it's too lean, it could be due to insufficient fuel pressure, clogged fuel injectors/fuel filter, etc.
- Ignition voltage too low. Are the ignition coils, spark plugs, and ignition cables okay?
- Faulty software in the engine control unit (You have software version 4792 for part number 04E 906 027 HN). According to KOBD2Check, this is already the latest software version for your engine control unit.

Regarding lambda values:
Okay, I'm ready. Please provide the German text you want me to translate.

You should be able to find the lambda values and adaptation factors under the advanced measurement data in the engine control unit.

Best regards, Rainer.

Hi,


"It seems like almost everything has been swapped out. What happens to the rail pressure in case of a fault? Has the ESD been checked again?" Fuel filter clean, and is the fuel also from a reputable source, not just a random gas station in a small village?

Our beloved 1.4 TSI (Golf VI Estate, manufactured in 2012) started to noticeably vibrate at idle for the first time after the second tank of fuel (I tend to be economical). However, this disappeared completely when we switched to a more reputable brand of gas station, and the issue could be reproduced. I blamed it on "contaminated" fuel back then... it might have been an isolated incident.

Want to measure compression?

Just for clarification - how does the MSG (Motor Supervisory System) detect misfires? Is it based on fluctuations in engine speed, readings from the knock sensors, or the lack of electrical load from individual ignition coils?
The logic should be the same for all gasoline engines.
hg
Herbert.

The error combination "P0301/P0304, which indicates cylinders 1+4, or P0302/P0303, which indicates cylinders 2+3" suggests that two cylinders each are connected to a spark plug. Can you confirm this based on the repair manual? Confirm documents?
In addition, in this specific error case, the MSG (Message Sequence Number) is not resolved to the individual cylinder (although it probably could be).
hg
Herbert.

The 1.4 TSI CZDA engine has four individual ignition coils. As far as I can see, the error detection is based on crankshaft speed, values from the O2 sensors, and knock sensors. The workshop measured these and they appear normal in VCDS. However, this doesn't necessarily mean anything, since this error only occurs rarely and the workshop couldn't reproduce it. As mentioned, the spark plugs, coils, and injectors have already been replaced, and the engine and valves have been cleaned. Most importantly, there is NO misfiring; the engine runs smoothly. To me, it sounds almost like a phantom error from the Mtsg system... but I'm just looking for your input on this.

The engine has been warmed up (e.g., on the highway or in heavy traffic).
- The engine is switched off (for a few minutes or a maximum of 1 hour).
- Afterwards, a city drive. After a few minutes at a traffic light, the check engine light (MIL) started flashing.


First, the highway, and then a heat buildup due to standstill traffic.
So, something is getting warm that shouldn't be getting warm.
And if you continue driving after that, it won't happen again, right?
Maybe what I'm about to say is nonsense, but if it were my car, I would replace the water pump.
They have a plastic impeller attached to a steel shaft, and if it gets too hot, it can detach and slip.
Of course, it will solidify again when the temperature drops.
If any of the sensors on the engine block cannot withstand this temperature, it could also explain the misfires.
Perhaps, as a test, you could try warming the relevant sensor with a heat gun while the engine is warm.
Alternatively, if the error occurs, use an infrared thermometer to measure the actual temperature of the sensor.
And of course, the outlet of the water pump as well.
Best regards, Frank.

It's probably not due to any individual components of the ignition or fuel injection system.
It is noticeable that the voltage of the second lambda sensor drops significantly towards the lean side several seconds before the start of the misfires.
Suggestion: Log lambda values, misfires, and MIL status (if possible) along with RPM, LM, and EM during the misfire phase. Are there any other measurement parameters available from the oxygen sensor?
hg
Herbert.