24 SENR9977 Systems Operation Section The engine oil pressure sensor is also an active sensor with three wires and a power supply. The sensor provides the ECM with a measurement of engine oil pressure. The ECM can warn the operator of possible conditions that can damage the engine. This includes the detection of a blocked oil filter. Primary Speed/Timing Sensor The operating range for the engine oil pressure sensor ....................... 110 to 882 kPa (16 to 128 psi) Required accuracy .........
±3% of maximum pressure Temperature Sensors g01133334 Illustration 30 Primary speed/timing sensor (1) Negative terminal (2) Positive terminal The primary speed/timing sensor is also a two-wire passive sensor. The sensor provides the ECM with the speed and the position of the engine from a timing wheel that is mounted on the crankshaft so that the ECM can request fuel and timing from the fuel injection pump. The timing wheel has one missing tooth that is located 70 degrees after top center. g01133312 Illustration 29 Temperature sensor The operating range for the primary speed/timing sensor ...........................................
142 to 3333 RPM (1) Negative terminal (2) Positive terminal The intake manifold temperature sensor and the coolant temperature sensor are two-wire passive sensors. The intake manifold temperature sensor provides the ECM with intake manifold air temperature so that the ECM can control the fuel for starting and injection timing. The coolant temperature sensor provides the ECM with coolant temperature so that the ECM can control injection timing. The temperature sensors are also used for engine monitoring. When the engine is cranking, the ECM uses the signal from the secondary speed/timing sensor in the fuel injection pump.
When the engine is running, the ECM uses the signal from the primary speed/timing sensor on the crankshaft. This speed/timing sensor is the primary source of the engine position. Note: If the primary speed/timing sensor fails, the engine will be derated and the engine will continue to operate on the secondary speed/timing sensor. Refer to Troubleshooting, RENR2696 for more information. The operating range for the temperature sensors ..................... −40° to 150°C (−40° to 302°F) Required accuracy for sensor ........... ±1 °C (±1.8 °F)