DDEC TROUBLESHOOTING
2.3.6
The Synchronous Reference Sensor and Timing Reference Sensor
These sensors control the timing of the engine. The SRS sensor provides a "once per cam
revolution" signal and the TRS sensor provides a "36 per crankshaft revolution" signal. Working
together, these sensors tell the ECM which cylinder is at top-dead-center for cylinder firing.
Precise monitoring of piston position allows for optimum injection timing, resulting in excellent
fuel economy and performance with low emissions. See Figure 2-5 for the SRS and the TRS.
Figure 2-5
Timing Reference Sensor and Synchronous Reference Sensor
2.3.7
Oil and Fuel Temperature Sensors
The oil temperature sensor optimizes idle speed and injection timing to improve cold startability
and reduce white smoke. This sensor will activate the engine protection system if the oil
temperature is higher than normal.
All information subject to change without notice.
6SE497 9709 Copyright © 1997 DETROIT DIESEL CORPORATION
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