Monitor Description

The fuel pump control ECU monitors the fuel pump drive circuit.

When a malfunction is detected in the fuel pump drive circuit, the diagnosis output circuit in the fuel pump control ECU modifies the operation signal sent by the ECM to indicate that there is a malfunction.

When the fuel pump control ECU operation duty ratio is 3 to 65% and overcurrent in the fuel pump circuit is detected for 3 seconds or more, the diagnosis output circuit in the fuel pump control ECU modifies the operation signal sent by the ECM to indicate that there is a malfunction and the ECM stores a DTC.