Test Point 3 - Speed Transmitter
TEST POINT 3Note: An oscilloscope should be used to check the speed and reference mark transmitters.
Speed Transmitter
1. Turn off ignition and pull off multiple pin plug on DME control unit.
2. Connect and adjust oscilloscope.
Connect blue connection via locally made auxiliary wire on term. 8 and black connection on term. 27 of DME plug.
3. Start engine.
Sine oscillation, the amplitude of which must be more than 2.5 V from peak to peak, must be displayed on the screen.
If the transmitter signal is less than 2.5 V, check distance between starter gear ring and transmitter.
Specification: 0.8 ± 0.05 mm
If a transmitter signal is not displayed in spite of correct connection and correct adjustment of tester, measure power flow and insulation of speed transmitter.
Coil resistance term. 8 against term. 27.
Specification: 0.6 to 1.6k-ohm.
Insulation resistance term. 8 against term. 5.
Specification: more than 1 M-ohm.
Replace speed transmitter, if necessary.