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 the FPU, FPV or FPW terminal voltage is less than a certain value 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.