Soot particulate sensor control unit, component description - GF14.40-P-2020OM

ENGINE 651.9 in MODEL 212 (except 212.098/298) as of 9/1/13 with CODE 494 (US version) with CODE U77 (Diesel Emission control BLUETEC (SCR)) 

View of exhaust system on model 212.0 at the front left 

Fig 1: View Of Exhaust System - Model 212.0

Courtesy of MERCEDES-BENZ USA

Location 

The soot particulate sensor is located in the exhaust system downstream of the SCR catalytic converter. The soot particulate sensor control unit is located on the underfloor.

Task 

The soot particulate sensor detects the soot particle concentration in the exhaust downstream of the SCR catalytic converter and routes this information in the form of voltage signals to the soot particulate sensor control unit. This processes the information and sends it via drive train sensor CAN (CAN I) to the CDI control unit (N3/9).

Input and output signals 

The soot particulate sensor control unit evaluates the following input signals and issues corresponding output signals:

• Direct input signals
• CAN input signals from the CDI control unit
• CAN output signals to the CDI control unit

Direct input signals 

• Circuit 87

CAN input signals from the CDI control unit 

• Diagnosis requests

CAN output signals to the CDI control unit 

• Soot particulate concentration in the exhaust
• Diagnostic data

Body 

The soot particulate sensor is inseparably connected over a sensor line to the soot particulate sensor control unit. An integrated sensor heater that is controlled by the soot particulate sensor control unit, ensures that the soot particulate sensor is operational quickly.