Component description Charge-air, coolant and fuel temperature sensors Charge-air B197 (51.27421–0165) Characteristic R=f (- н ) 4 2 3 1 Plug connection Coolant / Fuel B124 (51.27421–0172) Characteristic R=f (- н ) 2 4 1 3 Plug connection Function The temperature sensors for charge air, coolant and fuel are NTC resistors. The coolant temperature sensor is located in the coolant circuit and the turbo air temperature sensor in the turbo air circuit after the intercooler. They supply the control unit with information relating to the coolant and turbo air temperature.
The fuel temperature sensor is part of the injection pump and measures the fuel temperature for determina- tion of the fuel density. Depending on the fuel density the control unit determines the injection quantity and thus also the duration of injection. 15