EGR Temperature Sensor: Description and Operation

GF07.04-S-6251SA Component Description For Exhaust Gas Recirculation Temperature Sensor

ENGINES 642.8 in MODEL 906
- with CODE (MG5) Engine OM 642 DE 30 LA, 140 kW (190 hp) 3800 rpm
- except CODE (ZU7) National version for Canada
- except CODE (ZU8) National version for USA

ENGINES 642.8 in MODEL 639
- with CODE (XZ1)
- with CODE (MZ0) Blue EFFICIENCY

View of engine from front right, shown on model 906






B2/14 Hot film mass air flow sensor
B5/8 Boost pressure sensor
B19/15 Exhaust gas recirculation cooler temperature sensor
B50/6 Fuel temperature sensor
Y74/6 Pressure control valve
Y94/4 Quantity control valve

View of engine from front right, shown on model 639






B2/14 Hot film mass air flow sensor
B5/8 Boost pressure sensor
B19/21 Exhaust gas recirculation cooler temperature sensor
B50/6 Fuel temperature sensor
Y74/6 Pressure control valve
Y94/4 Quantity control valve

Location
The exhaust gas recirculation cooler temperature sensor located on the exhaust outlet of the exhaust gas recirculation cooler.

Task
The exhaust gas recirculation cooler temperature sensor determines the exhaust temperature downstream of the exhaust gas recirculation cooler.

The determined exhaust temperature is used by the CDI control unit (N3/30) to monitor the cooling function of the exhaust gas recirculation cooler.

Design
The exhaust gas recirculation cooler temperature sensor consists of a metallic housing with a resistor with positive temperature coefficients (PTC).

Function
The integral PTC resistor in the exhaust gas recirculation cooler temperature sensor changes its electrical resistance according to the exhaust gas temperature. The change in resistance results in a change in voltage which is used by the CDI control unit to compute the exhaust temperature downstream of the exhaust gas recirculation cooler.

PTC means that the electrical resistance increases for an increasing temperature (PTC thermistor).