Fuel Pump Monitor (Without Fuel Pump Driver Module)

1999 Ford Mustang GT, 2D Convertible, StandardSECTION Fuel Pump Monitor (Without Fuel Pump Driver Module)
WARNING: This page does not describe the selected car, but rather 32 other vehicles, including the 2002 Mercury Sable, 2002 Mercury Mountaineer, 2002 Mercury Grand Marquis, 2002 Mercury Cougar, and 2002 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.

The Fuel Pump Monitor (FPM) circuit is spliced into Fuel Pump Power (FP PWR) circuit and is used by PCM for diagnostic purposes. PCM sources a low current voltage down FPM circuit. With fuel pump off, voltage is pulled low by path to ground through fuel pump. With fuel pump off and FPM circuit low, PCM can verify FPM and FP PWR circuits are complete from FPM splice through fuel pump to ground. This also confirms that FP PWR or FPM circuits are not shorted to power.

With fuel pump on, voltage is supplied from fuel pump relay to FP PWR and FPM circuits. With fuel pump on and FPM circuit high, PCM can verify FP PWR circuit from fuel pump relay to FPM splice is complete. It can also verify that fuel pump relay contacts are closed and battery voltage is supplied to fuel pump relay.

RENDER: 1.0x

NO RELATED

Recommended Tools & Savings

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Affiliate disclosure: We may earn a commission at no extra cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.