Volvo D13 User Manual

PA1561 

5 

temperature coefficient, which means the sensor 
resistance will decrease as the engine oil 
temperature increases.  

The Engine Oil Temperature Sensor is located 
in the oil pan. 

Exhaust Temperature Sensor (DPF Sensors) 

The exhaust gas temperature sensor detects 
exhaust gas temperature for DPF protection as 
well as DPF regeneration control. The sensor 
modifies a voltage signal from the control unit. 
The modified signal returns to the control unit as 
the exhaust temperature at that specific location 
of the exhaust. The sensor uses a thermistor 
that is

 sensitive to the change in temperature.  

The Exhaust Temperature Sensors are located in 
the DPF assembly.  

Fuel Pressure Sensor  

The fuel pressure sensor contains a diaphragm 
that senses fuel pressure. A pressure change 
causes the diaphragm to flex, inducing a stress 
or strain in the diaphragm. The resistor values in 
the sensor change in proportion to the stress 
applied to the diaphragm and produces an 
electrical output.  

The Fuel Pressure Sensor is located on top of 
the fuel filter housing.  

Intake Air Temperature and Humidity (IATH) 
Sensor  

The Intake Air Temperature and Humidity (IATH) 
Sensor contains a thermistor and a capacitive 
sensor. The resistance of the thermistor varies 
inversely to temperature. The output of the 
capacitive sensor increases as the humidity of 
the surrounding air increases. By monitoring the 
signals from both portions of the sensor, the 
Engine Management System (EMS) Module 
calculates the temperature and humidity of the 
air passing through the air filter housing.  

The Intake Air Temperature and Humidity (IATH) 
Sensor is located in the air intake tube just 
downstream from the air filter canister. 

Intake Manifold (Boost) Temperature Sensor  

The Intake Manifold (Boost) Temperature 
Sensor is a thermistor whose resistance varies 
inversely to temperature. The sensor has a 
negative temperature coefficient, which means 
the sensor resistance will decrease as the inlet 

air temperature increases. 

The Intake Manifold (Boost) Temperature 
Sensor is located in the intake manifold.  

Intake Manifold Pressure Sensor 

The Intake Manifold Pressure Sensor contains a 
pressure sensitive diaphragm and an electrical 
amplifier. Mechanical pressure applied to the 
diaphragm causes the diaphragm to deflect and 
the amplifier to produce an electrical signal 
proportional to the deflection.  

The Intake Manifold Pressure Sensor is located 
on the air inlet pipe before the intake manifold.  

The Throttle Position Sensor is a potentiometer 
that is mechanically linked to the accelerator 
pedal. A potentiometer is a variable resistor 
whose resistance will change as the pedal is 
pressed. As the resistance changes, the signal 
voltage of the sensor changes indicating the 
accelerator pedal position. 

The Throttle Position Sensor is located above 
the accelerator pedal. The sensor is designed to 
improve the driver’s control by reducing 
sensitivity to chassis motion. This sensor 
provides the driver’s fuel request input to the 
VECU. 

Turbo Speed Sensor  

The Turbo Speed Sensor informs the EMS of 
the turbo shaft speed. The sensor does not read 
from the vanes, but reads from the shaft. The 
Engine Management System (EMS) Module 
uses this signal in conjunction with the VGT 
position sensor signal to control the speed of the 
turbocharger and therefore optimize the intake 
manifold pressure. 

The Turbo Speed Sensor is mounted in the 
center of the turbocharger.  

Variable Geometry Turbocharger Smart 
Remote Actuator (VGT SRA)  

The Variable Geometry Turbocharger Smart 
Remote Actuator (VGT SRA) takes the position 
commands from the EMS, moves the nozzle of 
the turbocharger to the desired position, and 
performs all of the diagnostics and self checks 
on the actuator.