Engine Speed/Cylinder Reference Sensors

Fig. 65 Pulse transmitter plug:

The engine speed sensor, and cylinder reference sensor are mounted in the transmission bellhousing. The speed sensor uses the teeth of the ring gear, and the reference sensor uses steel dowels on the face of the flywheel for their respective signals. To test the transmitter:
1. Disconnect each senders' plug.
2. Connect an oscilloscope to connections 1 and 2 of the sender, and crank the engine. Scope pattern should look like:

Fig. 6 Speed transmitter scope pattern.:

Engine Speed Sensor -- Fig. 6.

Fig. 5 Reference sensor scope pattern:

Cylinder Reference Sensor -- Fig. 5.

3. Measure resistance between terminals 1 and 2. Resistance should be, 960 Ohms ± 10%
4. Replace the transmitter if it fails either test.
Note: The preferred method of testing is with an oscilloscope. The scope pattern is more important than the resistance.