Dodge R1500 1999 Service Manual page 1567

Fig. 26: Single Injector - Known Good - Voltage Pattern
EXAMPLE #8 - CURRENT CONTROLLED DRIVER
These two known-good waveform patterns are from a GM 2.0L In-
Line 4 VIN [1]. Fig. 27 illustrates the 78 volt inductive spike that
indicates a zener diode is not used. The second waveform, Fig. 28, was
taken during hot idle, closed loop, and no load.