C-10 and C-12 Truck Engines
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| Illustration 1 | g00881822 |
Top view (1) Engine speed sensor (2) Coolant temperature sensor (3) Inlet air temperature sensor (4) Inlet manifold pressure sensor (5) Fuel temperature sensor (6) Atmospheric pressure sensor | |
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| Illustration 2 | g00881762 |
Front view (7) Speed sensor or timing sensor (8) Coolant temperature sensor (9) Fuel temperature sensor | |
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| Illustration 3 | g00881767 |
Right side view (7) Oil pressure sensor | |
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| Illustration 4 | g00881771 |
(11) Fuel temperature sensor (12) Atmospheric pressure sensor (13) Engine wiring harness (14) Electronic control module (ECM) | |
3406E Truck Engines
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| Illustration 5 | g00881828 |
Left side view (1) Engine speed/timing sensor (2) Engine speed/timing sensor P9/J9 connector (3) Fuel temperature sensor P23. (4) Atmospheric pressure sensor connector P22/J22 (5) Sensor for the inlet manifold air temperature (6) Injector connector J5/P5 (7) Boost pressure sensor (8) Ground point for the OEM (9) Sensor for the inlet manifold pressure J3/P3 (10) Engine control module P2 (11) ECM connector J2/P2 that is for the engine (12) ECM connector J1/P1 that is for the OEM (13) Inlet air temperature sensor (14) Vehicle speed/TC probe connector J24/P24 | |
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| Illustration 6 | g00451551 |
Right side view (15) Oil pressure sensor connector (16) Coolant temperature sensor | |
Atmospheric Pressure Sensor
The atmospheric pressure sensor is an absolute pressure sensor that measures crankcase pressure. Both the boost pressure and the oil pressure are communicated to the service tools and over the data link. The two pressures are calculated by subtracting the reading for the atmospheric pressure sensor. The atmospheric pressure sensor measures pressure from 0 (0) to 116 kPa (17 psi). The atmospheric pressure sensor is supplied with 5 VDC by the ECM.
Inlet Manifold Pressure Sensor
The boost pressure sensor is an absolute pressure sensor that measures inlet manifold pressure. The difference between the inlet manifold pressure measurement and the pressure that is measured by the atmospheric pressure sensor is called the boost pressure. The information is communicated to the service tools and over the data link. The boost pressure sensor measures pressure from 20 kPa (3 psi) to 340 kPa (49 psi). The boost pressure sensor is supplied with 5 VDC by the ECM.
Coolant Level Sensor
The coolant level sensor is purchased by the OEM and the coolant level sensor is installed by the OEM. The coolant level sensor is the only optional sensor. The coolant level sensor is selected through the ECM Customer Programmable Parameter. The ECM Customer Programmable Parameter is protected by Customer Passwords.
Coolant Temperature Sensor
The engine coolant temperature is measured by an electronic sensor that is mounted on the water outlet housing. The signal from the coolant temperature sensor is used to modify the fuel mixture and the timing. This results in improved cold starting and improved cleanup of white smoke. The ECM supplies the coolant temperature sensor with 5.0 ± 0.5 VDC. The output voltage of the sensor is from 0.5 VDC to 4.5 VDC. The output voltage of the sensor depends on the temperature of the engine coolant. The coolant temperature sensor is used to indicate cold mode operation. The coolant temperature sensor is also used for engine monitoring.
Fuel Temperature Sensor
The Fuel Temperature is monitored in order to adjust the calculations for the fuel rate. The fuel temperature is also monitored for a power correction when the fuel temperatures exceed 30°C (86°F) in order to provide constant power. The maximum power correction is achieved at 70°C (158°F). A fuel temperature that exceeds 90°C (194°F) for ten minutes will cause a diagnostic code to be logged.
Inlet Air Temperature Sensor
Intake manifold temperature is used for the cooling fan driver and Engine Monitoring. The inlet air temperature sensor is used in order to warn the driver of an excessive inlet manifold air temperature. The air inlet temperature sensor will not cause an engine derate or an engine shutdown.
The air inlet temperature must exceed the temperatures that are indicated for thirty seconds before a diagnostic code is logged, following engine start-up. A diagnostic code for the High Inlet Manifold Temperature is triggered at 80°C (176°F). A diagnostic code for the Very High Inlet Manifold Temperature is triggered at 110°C (230°F). The codes that are associated with the inlet air temperature sensor are still available when Engine Monitoring is programmed to "OFF". This is unlike the diagnostic codes that are associated with the engine monitoring. The Warning Lamp is also turned on if Engine Monitoring is programmed to "Warning", "Derate", or "Shutdown".
Oil Pressure Sensor
The oil pressure sensor is an absolute pressure sensor that measures oil pressure in the gallery. The oil pressure is communicated over the data link and the oil pressure is displayed by the service tools. The ECM uses the sensor input only if the parameter for Engine Monitoring is programmed to "Warning", "Derate", or "Shutdown". The oil pressure sensor measures pressure from 0 kPa (0 psi) to 690 kPa (100 psi). The sensor is supplied by the ECM with 5 VDC.
Engine Speed/Timing Sensor
The engine speed/timing sensor is used to determine both engine speed and fuel injection timing. The sensor detects this information from a wheel on the camshaft. Timing calibration is performed by connecting a magnetic sensor. The sensor is connected through the vehicle speed circuit, sensing motion of the crankshaft.
Throttle Position Sensor
The throttle position sensor is an electronic sensor that is connected to the accelerator pedal. The throttle position sensor sends a Pulse Width Modulated Signal to the ECM.
Vehicle Speed Sensor
The vehicle speed sensor is an electromagnetic pickup that measures vehicle speed. The sensor measures vehicle speed from the rotation of the gear teeth that are in the drive train of the vehicle.