2.4 Sensors and Relays [1] NE Sensor (crankshaft position sensor) When the signal holes on the flywheel move past the sensor, the magnetic line of force passing through the coil changes, generating alternating voltage. The signal holes are located on the flywheel at 7.5-degree intervals. There are a total of 45 holes, with holes missing in three places. Therefore, every two revolutions of the engine outputs 90 pulses. This signal is used to detect the engine speed and the crankshaft position in 7.5-degree intervals.
[2] TDC sensor (cylinder recognition sensor) Similar to the NE sensor, the sensor utilizes the alternating voltage generated by the changes in the magnetic line of force passing through the coil. The disc-shaped gear located in the center of the supply pump camshaft has a cog (U-shaped cutout) at 120-degree intervals, plus one tooth in an additional location. Accord- ingly, every two revolutions of the engine outputs seven pulses. The combination of the NE pulse, TDC pulse is rec- ognized as the No. 1 cylinder reference pulse.
NE (crankshaft angle) sensor Q000100E TDC (cylinder recognition) sensor Q000101E A combination of the NE pulse and the TDC pulses are used for the cylinder reference pulse, and the irregular pulse is used to determine the No. 1 cylinder. ECU TDC Input circuit NE Input circuit Q000102E No.6 cylinder TDC pulse No.1 cylinder recognition pulse No.1 cylinder TDC pulse 0°CR 120°CR 240°CR 360°CR 480°CR 600°CR 720°CR Aux.
NE pulse #1 TDC #5 TDC #3 TDC #6 TDC #2 TDC #4 TDC #1 TDC 75°CR 75°CR 75°CR 75°CR 75°CR 75°CR 75°CR 105°CR NE pulse 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 14 0 2 4 6 8 10 12 0 2 4 6 8 No.1 cylinder NE reference pulse No.6 cylinder NE reference pulse Q000103E 14