Location
The exhaust gas temperature sensor upstream of the diesel oxidation catalytic converter (B67) is screwed in from the outside into the deflection chamber upstream of the diesel oxidation catalytic converters (DOC).
1 | Exhaust aftertreatment unit |
B67 | Exhaust temperature sensor upstream of diesel oxidation catalytic converter |
W14.40-1579-76
Task
Via the exhaust gas temperature sensor upstream of the diesel oxidation catalytic converter (B67), the aftertreatment control module (ACM) (A60) detects the exhaust flow temperature in the deflection chamber upstream of the diesel oxidation catalytic converters (DOC).
Structure
The exhaust gas temperature sensor upstream of the diesel oxidation catalytic converter (B67) consists of a stainless steel housing. The housing contains a measuring element, a PTC resistor. PTC stands for "Positive Temperature Coefficient" and means that the electrical resistance increases as the temperature increases.
Function
The exhaust gas flowing by at the exhaust gas temperature sensor upstream of the diesel oxidation catalytic converter (B67) influences, depending on the temperature, the measuring element on the inside and results in a change of its electrical resistance.
Because a constant measuring current flows through the exhaust gas temperature sensor upstream of the diesel oxidation catalytic converter (B67), a voltage drop occurs due to the resistance variation. Based on the voltage drop, the aftertreatment control module (ACM) (A60) determines the corresponding temperature.