Engine | 900.91/92 in model 000.001 |
with BlueTec | |
Engine | 902.91/93 in model 000.001 |
with BlueTec | |
Engine | 904.94/95/96/97 in model 000.001 |
with BlueTec | |
Engine | 906.93/94/95/96/98/99 in model 000.001 |
with BlueTec | |
Engine | 924.91/93/94 in model 000.001 |
with BlueTec | |
Engine | 925.9 in model 000.001 |
with BlueTec | |
Engine | 926.91/92/93/95/97/98 in model 000.001 |
with BlueTec |
Location
The temperature sensor upstream of the SCR catalytic converter is screwed into the exhaust gas aftertreatment unit (1) from the outside.
1 | Exhaust aftertreatment unit |
B115 | Temperature sensor upstream of SCR catalytic converter |
G49.20-A055-06
Task
The exhaust gas aftertreatment (ACM) control unit (A60) records the temperature of the exhaust flow in the chamber upstream of the SCR catalytic converter via the temperature sensor upstream of the SCR catalytic converter.
Structure
The temperature sensor upstream of the SCR catalytic converter consists of a stainless steel housing. The inside contains a measuring element, a temperature-dependent resistance with a positive temperature coefficient (PTC).
PTC stands for "positive temperature coefficient:" The electrical resistance increases as the temperature increases (PTC thermistor).
Function
The exhaust gas flowing past the exhaust gas temperature sensor upstream of the SCR catalytic converter influences, depending on its temperature, the measuring element on the inside and results in a change of its electrical resistance. As the temperature sensor upstream of the SCR catalytic converter has a constant measuring current flowing through it, the resistance change causes a voltage drop via which the exhaust gas aftertreatment (ACM) control unit can infer the associated temperature value.