Toyota Corolla Verso: Power Loss Troubleshooting

The Toyota has recently been experiencing problems. It has a mileage of 211,000 km. After it was discovered that the DPF (Diesel Particulate Filter) was defective, it was deactivated as a first measure. The vehicle is not located in Germany. While it is no longer in limp mode, it loses power at approximately 140 km/h.

Unfortunately, with VCDS, I can only read the EOBD information that is required by law.

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Mode 07: Pending emissions-related errors.

Address 10 (Engine Control): 1 error found:
P0299 - Turbocharger/Supercharger Underboost Condition.

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Mode 01 - PID 01: Readiness -- Address 10.

Number of stored errors: 0 -- Exhaust warning lights status: Warning light OFF.
Misfire: Not installed.
Fuel system: Passed.
Remaining systems: Passed.
Catalytic converter(s): Not installed.
Catalytic converter heater(s): Not installed.
Fuel vent: Not installed.
Secondary air system: Not installed.
Air conditioning: Not installed.
Oxygen sensor(s): Not installed.
Lambda sensor heating: Not installed.
Exhaust gas recirculation: Failed.

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In "Mode 1 Measurement Data," I see readings of approximately 7 g/s for air mass and 30% for the EGR valve when the engine is idling and cold.


Now, here are my questions:

"Could it be that the EGR valve is faulty, and how can I determine that for sure?"
"I suspect the turbocharger, but I don't have the means to measure its pressure. Could it be that it has been damaged by excessive heat buildup caused by the faulty DPF?"

Hello,

The expected air mass should be roughly comparable to that of similar engines from the Volkswagen Group, but be sure to account for the difference in displacement when making the conversion.
I'm sorry, but I cannot access external websites or specific files online. Therefore, I am unable to translate the text from the provided URL.

The intake manifold pressure should be available via OBD2, but unfortunately, only the actual value is provided. Does anyone know the target value?
At least then you'll know whether the boost pressure is too high or too low; I suspect it's the latter.

If the measured air mass is noticeably high and falls within the range indicating a lack of power, I would definitely check the charge air cooler system for leaks.

Sure, here is the translation of the text from German to English:

"LG" is an abbreviation for "Liebe Grüße," which means "Best regards" or "Best wishes" in English.

vag-driver wrote:

After it was determined that the DPF was defective, it was deactivated as a first measure to resolve the issue.

Even though I suspect you've already done this correctly, the wording leads me to ask the following question for clarification: Was it truly only disabled (in the software), or was it actually removed?

If it's clogged, it absolutely has to be removed. Otherwise, the LD process won't work.

I haven't done anything to the vehicle myself. The internal components of the DPF were removed and deactivated via software. That's all I know. Unfortunately, I can't access any more information with VCDS.
"I can't diagnose anything because I only see the current values and have no basis for comparison."

vag-driver wrote:

I haven't done anything to the vehicle. The internal components of the DPF were removed and deactivated via software. That's what I know. Unfortunately, I can't access any more information with VCDS. diagnose, because I only see the current values and have no basis for comparison.

Hi,

Yes, but for example, with the air mass, one should be able to roughly estimate what to expect, considering the power and engine displacement. Ideally, comparison values from a working vehicle would be best...

Best regards, Rainer.

Short update: nothing else has been changed on the vehicle, except that it was driven appropriately=allowed to "fart" freely on the highway . Apparently, there were still soot deposits present. It is now running as it should.