Hummer H2. Manual — part 164

Fig. 23: Injector Bank - Known Good - Voltage Pattern

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Waveforms - Injector Pattern Tutorial

Fig. 24: Injector Bank - Known Good - Voltage Pattern

EXAMPLE #6 - CURRENT CONTROLLED DRIVER

This known-good pattern from a Ford 3.0L V6 PFI VIN [U] illustrates that a zener diode inside the computer is
used to clamp the injector's inductive kick to 35-volts on this system. See Fig. 25 .

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Waveforms - Injector Pattern Tutorial

Fig. 25: Injector Bank - Known Good - Voltage Pattern

EXAMPLE #7 - CURRENT CONTROLLED DRIVER

This known-good waveform from a Ford 5.0L V8 CFI VIN [F] was taken during hot idle, closed loop, and no
load. See Fig. 26 .

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Waveforms - Injector Pattern Tutorial

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. Fig. 27 illustrates the
78 volt inductive spike that indicates a zener diode is not used. The second waveform, Fig. Fig. 28 , was taken
during hot idle, closed loop, and no load.

1998 Chevrolet Pickup C1500

GENERAL INFORMATION Waveforms - Injector Pattern Tutorial