Signal Wave Form & Data

This figure shows the voltage wave form on channel 1 in idling.

Fig 1: Voltage WAVE FORM On Channel 1 In Idling

Courtesy of HYUNDAI MOTOR CO.

1. At point (1), the measured voltage should be nearly battery voltage.
2. The measured voltage at point (2) is the surge voltage and is approximately 56V.
3. The measured voltage at point (3) is below 1V and the period is between 1.8ms and 4ms in idling when warmed up condition.

When the PCM energizes the injector by grounding the control circuit, the circuit voltage should below (theoretically 0V) and the fuel is injected. When the PCM de-energizes the injector by opening control circuit, the fuel injector is closed and circuit voltage should be peak for a moment.