ECM Monitored System

The ECM can detect certain problems in the electrical system.

Open or Shorted Circuit - The ECM will not distinguish between an open or a short to ground, however the ECM can determine if there is excessive
current on a circuit, such as a short to voltage or a decrease in component resistance.

Output Device Current Flow - The ECM senses whether the output devices are electrically connected.

If there is a problem with the circuit, the ECM senses whether the circuit is open, shorted to ground (-), or shorted to (+) voltage.

Fuel Pressure: High fuel pressure is controlled by the fuel injection pump, fuel pressure solenoid, and fuel rail pressure sensor. The ECM uses inputs from the sensor and solenoid to calculate and determine if a high fuel pressure problem exists.

Fuel Injector Malfunctions: The ECM can determine if a fuel injector has an electrical problem. The fuel injectors on the diesel engine are controlled by the ECM.