Post Injection 3 consistently showing 1.0–1.3 mg/str – DGTE / Delphi DCM6.2
Posted: Tue Nov 03, 2026 9:14 pm
Post Injection 3 consistently showing 1.0–1.3 mg/str – DGTE / Delphi DCM6.2
Hello everyone,
I would appreciate some technical insight into the Post Injection 3 parameter displayed by the VAG DPF application.
Vehicle and ECU information:
- Vehicle: 2019 SEAT Ateca 1.6 TDI DSG
- Engine code: DGTE
- ECU: Delphi DCM6.2
- ECU software number: 04L906056TG
- Software version: 7226
- Hardware number: 04L907445G
- ECU identifier: D11EV_ECM16TDI030
- Current mileage: approximately 93,000 km
1. Post Injection 3 behaviour at idle
Even when the engine is fully warm and idling, Post Injection 3 frequently shows approximately 1.21–1.31 mg/str.
Post Injection 1 and Post Injection 2 remain at 0.00 mg/str.
This behaviour is not limited to active DPF regeneration.
2. Post Injection 3 behaviour while driving
I have also monitored the parameter while driving, and its behaviour is particularly interesting:
- During normal driving with the accelerator pressed, Post Injection 3 generally shows approximately 1.21–1.31 mg/str.
- When I release the accelerator and the vehicle enters engine braking/deceleration, the value drops to 0.00 mg/str.
- As the vehicle slows down further, without pressing the accelerator again, Post Injection 3 becomes active again and returns to approximately 1.21–1.31 mg/str.
- This behaviour occurs regardless of the DSG gear.
- Post Injection 1 and 2 remain at 0.00 mg/str during these observations.
The value appears to change according to the engine operating condition rather than being associated exclusively with DPF regeneration.
3. Observations from actual driving
I recorded two screenshots during my morning commute:
At 92,992 km:
- Post Injection 3: 1.00 mg/str
- Post Injection 1 and 2: 0.00 mg/str
- Calculated soot mass: 14.07 g
- Distance since last DPF regeneration: 102 km
- Regeneration duration: 0 minutes
- DPF inlet gas temperature: 207 °C
At 93,000 km:
- Post Injection 3: 1.23 mg/str
- Post Injection 1 and 2: 0.00 mg/str
- Calculated soot mass: 14.47 g
- Distance since last DPF regeneration: 109 km
- Regeneration duration: 0 minutes
- DPF inlet gas temperature: 192 °C
Therefore, Post Injection 3 is not simply appearing during an active DPF regeneration.
4. Fuel consumption
The vehicle has no noticeable drivability problems.
- No fault codes currently present.
- Engine runs normally.
- No noticeable loss of power.
- No abnormal smoke.
- No obvious injector-related symptoms.
However, compared with other vehicles equipped with the same 1.6 TDI engine, my vehicle consumes approximately 1 litre/100 km more fuel under comparable driving conditions.
I am wondering whether the persistent Post Injection 3 reading could be related to this difference in fuel consumption.
5. Questions for the developer and experienced users
I found the previous forum explanation stating that Post Injection 3 is used less frequently during normal driving, while all three post-injections can be used during DPF regeneration.
This is why my observations are confusing.
Could you please clarify:
1. What exactly does the Post Injection 3 value represent in the VAG DPF application?
2. Is it the actual commanded quantity of the third late post-injection, or a calculated/requested value?
3. Can Post Injection 3 legitimately remain around 1.0–1.3 mg/str during normal driving and warm idle, outside active DPF regeneration?
4. Can this behaviour be related to NOx catalyst desulphurisation or another emissions-control strategy?
5. Has the Post Injection 3 parameter been fully verified on the DGTE engine with Delphi DCM6.2 software version 7226?
6. Could there be a PID/CAN parameter mapping difference on this ECU software version?
7. Is there any known reason why this parameter becomes zero during engine braking and returns while the vehicle is slowing down?
I would particularly appreciate clarification from the application developer regarding the exact ECU signal and its interpretation.
I am not assuming that the reading indicates a fault. I simply want to understand why Post Injection 3 behaves this way on my vehicle and whether it could explain the approximately 1 L/100 km higher fuel consumption.
Thank you in advance for your help.
Hello everyone,
I would appreciate some technical insight into the Post Injection 3 parameter displayed by the VAG DPF application.
Vehicle and ECU information:
- Vehicle: 2019 SEAT Ateca 1.6 TDI DSG
- Engine code: DGTE
- ECU: Delphi DCM6.2
- ECU software number: 04L906056TG
- Software version: 7226
- Hardware number: 04L907445G
- ECU identifier: D11EV_ECM16TDI030
- Current mileage: approximately 93,000 km
1. Post Injection 3 behaviour at idle
Even when the engine is fully warm and idling, Post Injection 3 frequently shows approximately 1.21–1.31 mg/str.
Post Injection 1 and Post Injection 2 remain at 0.00 mg/str.
This behaviour is not limited to active DPF regeneration.
2. Post Injection 3 behaviour while driving
I have also monitored the parameter while driving, and its behaviour is particularly interesting:
- During normal driving with the accelerator pressed, Post Injection 3 generally shows approximately 1.21–1.31 mg/str.
- When I release the accelerator and the vehicle enters engine braking/deceleration, the value drops to 0.00 mg/str.
- As the vehicle slows down further, without pressing the accelerator again, Post Injection 3 becomes active again and returns to approximately 1.21–1.31 mg/str.
- This behaviour occurs regardless of the DSG gear.
- Post Injection 1 and 2 remain at 0.00 mg/str during these observations.
The value appears to change according to the engine operating condition rather than being associated exclusively with DPF regeneration.
3. Observations from actual driving
I recorded two screenshots during my morning commute:
At 92,992 km:
- Post Injection 3: 1.00 mg/str
- Post Injection 1 and 2: 0.00 mg/str
- Calculated soot mass: 14.07 g
- Distance since last DPF regeneration: 102 km
- Regeneration duration: 0 minutes
- DPF inlet gas temperature: 207 °C
At 93,000 km:
- Post Injection 3: 1.23 mg/str
- Post Injection 1 and 2: 0.00 mg/str
- Calculated soot mass: 14.47 g
- Distance since last DPF regeneration: 109 km
- Regeneration duration: 0 minutes
- DPF inlet gas temperature: 192 °C
Therefore, Post Injection 3 is not simply appearing during an active DPF regeneration.
4. Fuel consumption
The vehicle has no noticeable drivability problems.
- No fault codes currently present.
- Engine runs normally.
- No noticeable loss of power.
- No abnormal smoke.
- No obvious injector-related symptoms.
However, compared with other vehicles equipped with the same 1.6 TDI engine, my vehicle consumes approximately 1 litre/100 km more fuel under comparable driving conditions.
I am wondering whether the persistent Post Injection 3 reading could be related to this difference in fuel consumption.
5. Questions for the developer and experienced users
I found the previous forum explanation stating that Post Injection 3 is used less frequently during normal driving, while all three post-injections can be used during DPF regeneration.
This is why my observations are confusing.
Could you please clarify:
1. What exactly does the Post Injection 3 value represent in the VAG DPF application?
2. Is it the actual commanded quantity of the third late post-injection, or a calculated/requested value?
3. Can Post Injection 3 legitimately remain around 1.0–1.3 mg/str during normal driving and warm idle, outside active DPF regeneration?
4. Can this behaviour be related to NOx catalyst desulphurisation or another emissions-control strategy?
5. Has the Post Injection 3 parameter been fully verified on the DGTE engine with Delphi DCM6.2 software version 7226?
6. Could there be a PID/CAN parameter mapping difference on this ECU software version?
7. Is there any known reason why this parameter becomes zero during engine braking and returns while the vehicle is slowing down?
I would particularly appreciate clarification from the application developer regarding the exact ECU signal and its interpretation.
I am not assuming that the reading indicates a fault. I simply want to understand why Post Injection 3 behaves this way on my vehicle and whether it could explain the approximately 1 L/100 km higher fuel consumption.
Thank you in advance for your help.