Fuel Consumption: High Reading - Troubleshooting

Hello everyone,

I drive a Golf VII 1.6 TDI, manufactured in 2015, with an engine power of 81 kW (CXXB).
"On the way back from vacation, my car's check engine light (yellow) came on. The car didn't show any loss of power, but I read the error memory while on the road. It was a NOx error in the memory: 23716 - NOx trap, bank 1. The error could be easily cleared. What was noticeable was the fuel consumption according to the error log. Today, I read the memory again for verification. There were no errors in the memory, but the "fuel consumption" extended measurement value shows a nonsensical value of up to over 600 liters per hour."
"The onboard computer shows a normal fuel consumption (0.7L/h at idle), and the actual fuel consumption is also fine. I've attached an Autoscan, a log file from today, and the error log from my vacation trip. I'm worried that the incorrect value might affect the DPF regeneration. Does anyone have any idea which fault could be causing this incorrect fuel consumption value? Thanks in advance for your help. Best regards, Joest"

Hello,

If the actual consumption values are normal and the engine control unit software is up-to-date and original, then there is likely a bug in the factors used for the diagnostic values.

It happens from time to time. I wouldn't overthink it.

Regarding NOx emissions, it would be more appropriate to check the factors that influence NOx formation, or the NOx sensor itself.

Problems with the EGR system can cause high NOx emissions. The catalytic converter may also be an issue. Regarding AdBlue, problems can arise from insufficient AdBlue or a low urea content.

Best regards, Rainer.

Hello Rainer,

"Thank you for the quick response. I'll observe it for now. Currently, it's not throwing any error codes (other than the strange consumption value). It doesn't have AdBlue yet, so it's just an NOx storage catalyst with a particulate filter. Supposedly, that's enough for Euro 6. If the error code reappears, I'll check the lambda sensors before and after the catalytic converter. However, all the measured values seem plausible. The consumption value is mainly what concerns me, as I don't know which parameters it's based on."
Thanks again, and have a good evening. Best regards, Joest.