Technical Definition:

Fuel Pump Secondary Circuit High

Technical Description:

The fuel pump is powered by the fuel pump relay. When the PCM (powertrain control module) activates the fuel pump relay, voltage is supplied to the fuel pump and it pressurizes the fuel system. Some vehicles have a feedback on the fuel pump supply circuit. This is simply a circuit spliced into the voltage feed to the fuel pump. The splice is usually located close to the PCM.

Possible Causes:

• Bad FP relay
• Short to voltage on FP voltage supply circuit or feedback circuit
• Short to ground on PCM
• FP relay control circuit PCM
• FP relay control driver shorted to ground internally

Possible Symptoms:

• MIL (malfunction indicator lamp) illumination
• Fuel pump runs with key off
• Small amount of voltage present on FP (fuel pump) voltage supply circuit due to short

Fuel Pump Secondary Circuit High

Possible Solutions:

OBD-II Trouble Code Type:

Diagnostic Step:

Tech Notes:

– Blown Fuel Pump fuse
– Open Fuel Pump Monitor Circuit
– Faulty Fuel Pump Relay
– Damaged Engine Control Module (ECM)

Specific Makes: