Component Tests and General Diagnostics

Fig. 65 Pulse transmitter plug:

Fig. 67 Pulse transmitter scope pattern:

The pulse transmitter is mounted on the front of the engine, and gets its signals from the teeth cast into the vibration damper. This transmitter performs a dual function, taking the place of the separate speed and reference sensors that were mounted in the bellhousing at the rear of the engine on other models. The speed signal comes from the teeth in the vibration damper, while the reference signal is derived from two specific missing teeth. To test the transmitter:
1. Disconnect pulse transmitter plug.
2. Connect an oscilloscope to connections 1 and 2 of the pulse transmitter, and crank the engine. Scope pattern should look like Fig. 67.
3. Measure resistance between terminals 1 and 2, Fig. 65. Resistance should be 540 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.