2018 Diesel Cruze 6 speed manual regen not working

MichelleHCruze2018 said:

I know I have a NOX sensor not functioning, would this cause the total system sensors to all read in the negatives?

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No. The DPF and SCR are independent.

If both have an issue, the DPF takes priority. Which includes preventing a speed limit (DPF only causes a REP).

However, if the speed limit happens before the DPF fault, you will still get a speed limit.

MichelleHCruze2018 said:

So where to start for repairs. I haven't checked the sensors myself but codes read for NOx sensor and closed loop

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I would just ignore any SCR/DEF or NOx code until you get a successful regen.

Common problems which cause a regen issue are:

• The differential pressure sensor and pipes
• EGT sensor failures
• VGT control issues caused by vacuum leak, vacuum pump, or failed VGT Actuator.
• MAF and O2 Sensor Failures
• Other low boost causes such as a cracked intercooler up pipe or clogged intake

The 2.0L diesel uses an O2 sensor to run closed loop fueling which can affect the dpf. This is a separate sensor and is not one of the 2 NOx sensors, but in the parts catalog its possible NOx sensors will wrongly be labeled as "O2 Sensor". Make sure you don't get them mixed up. Also have fun explaining to a diesel mechanic how a diesel engine has an O2 sensor.