VCDS and OBD diagnostic device in the On-Board Diagnostics Shop
Diesel, Engine Technology and Vehicle Technology. Repair, Maintenance and Diagnostics (OBD).

Differential Pressure Sensors CFBG

 
New Topic Reply 🔗 ⭐ 🖨 Dieselschrauber - Index » Diesel Engine Technology
Author Message
brezelmann01
Profi-Schrauber
Profi-Schrauber


Joined: 09/14/2002
Posts: 714
Karma: +75 / -0   Thank you, like it!
Location: Niedersachsen

Premium Support

Post19-08-2011, 19:55    Subject: Differential Pressure Sensors CFBG Quote

Hello!

Today, I took a closer look under the hood. I noticed something about the DPF:
I found a total of three temperature sensors: one BEFORE the turbo, one BEFORE the DPF, and one AFTER the DPF. That seems okay. What struck me as odd was the differential pressure. I only found one connection point BEFORE the DPF, which was connected to the sensor. The other side of the sensor was connected to atmospheric pressure. Is that normal? It also looks like the connection AFTER the DPF is blocked with a blind nut.

Here are some photos of the sensor and the blind nut.



IMG_1952.JPG
 Description:
 Differenzdrucksensor (versteckt hinter dem Halter)
 File size:  1.51 MB
 Viewed:  22382 times

IMG_1952.JPG


IMG_1963.JPG
 Description:
 Blindstopfen nach DPF
 File size:  1.09 MB
 Viewed:  6776 times

IMG_1963.JPG

Audi A3 Sportback [8PA], 2.0 TDI CR [CFGB], STH mit FB

[VERKAUFT] Polo 6NF 1.4TDI (AMF) mit nachgerüstetem DPF, STH+FFB, Bj. 2000, 222tkm


Translated on 23-09-2026, 15:41.
Back to top Profile PM
dieselschrauber
Administrator
Administrator
Avatar-dieselschrauber

Joined: 04/12/2002
Posts: 18113
Karma: +800 / -0   Thank you, like it!
Location: St.Gallen
2018 Volkswagen T6 Consumption


Post19-08-2011, 20:22    Subject: Differential Pressure Sensors CFBG Quote

Hello,

Probably, the engine control unit simply estimates the pressure after the DPF. icon_wink.gif The advantage is that it saves a piece of pipe and a hose compared to a software function.
It might be sufficient to use a model that incorporates engine speed, fuel injection volume, and intake air mass to "estimate" sufficiently accurate values.

Best regards, Rainer.


Translated on 23-09-2026, 15:42.
Back to top Profile PM WWW Garage
vwSchrauber
Profi-Schrauber
Profi-Schrauber


Joined: 09/18/2008
Posts: 1262
Karma: +43 / -0   Thank you, like it!


Support

Post19-08-2011, 21:24    Subject: Differential Pressure Sensors CFBG Quote

I agree. The engine control unit (ECU) already has an atmospheric pressure sensor, and the resistance from the DPF outlet to the exhaust pipe is calculated based on a model.
selber schrauben - statt Werkstattpfusch


Translated on 23-09-2026, 15:43.
Back to top Profile PM
New Topic Reply 🔗 ⭐ 🖨 Dieselschrauber - Index » Diesel Engine Technology
Similar articles and topics
Topic Forum
No new posts Differential pressure sensor G450 to be calibrated/adjust... Faults & Documentation (Audi, VW, Seat/Cupra, Skoda)
No new posts DPF differential pressure sensor output voltage Faults & Documentation (Audi, VW, Seat/Cupra, Skoda)
No new posts P2453: DPF Differential Pressure Sensor Error Faults & Documentation (Audi, VW, Seat/Cupra, Skoda)
No new posts Rattle Noise CR TDI CFBG Engine - Diagnosis Diesel Engine Technology
No new posts Differential Pressure Sensor: Explained Diesel Engine Technology
No new posts T5 Differenzdrucksensor On-Board Diagnostics (OBD)
No new posts Differential Pressure Sensor Diesel Engine Technology
Jump to:  
You cannot post new topics in this forum.