G 1500 1/2 Ton Van V8-305 5.0L VIN H 4-bbl (1984)
![background image](/gmc/g_1500_1/2_ton_van/v8-305_5.0l_vin_h_4-bbl/Page-71001.png)
Engine Speed Sensor: Description and Operation
On all models with full function systems except V6-229 (1983 - 84 VIN code 9) engines, the ``R'' terminal on the 7 terminal ignition module provides
reference pulses to the ECM indicating engine RPM and crankshaft position.