Worry Code Fault Location Probable Crusade
P0231 Fuel pump relay -circuit contemptible Wiring unforesightful to earth, fire pump relay, Electronic countermeasures

We recommend Torque Pro

What Does Code P0231 Mean?

The internal burning locomotive engine needs three basic things to start and ply: air, fuel, and spark. With regards to this DTC (diagnostic trouble code), we'll represent focusing along fuel. The fuel system includes the fuel tank, a nonaggressive fuel pump, sometimes a high-pressure fire heart, fuel tubes and hoses, a fuel pressure regulator, and the fire injectors. The fuel pump and fuel injectors are operated electrically and electronically, so there are as wel fuses, relay race, and a controller for these. Usually, the controller is part of the ECM (engine control module), though some vehicles, such as some diesels, Crataegus laevigata have a separate fire injector driver module.

Usually, the fire pump relay is commanded aside the ECM. The ECM grounds the fuel pump relay control or first-string electric circuit, which and so feeds power to the fuel pump using the power operating theater secondary electric circuit. On some vehicles, turning the key on will bout the pump, along for a couple of seconds, to prime the organisation. If the ECM detects crank but non engine starting, using the RPM signalize from the tender position sensor, it volition turn off the fuel heart after a set period.

To ensure proper fuel system function, everything necessarily to work together. If there is insufficient fuel imperativeness, the fuel injectors won't be able to bear fuel properly, for instance. Light fuel blackmail can be caused by any number of electrical problems, unrivalled of which is poor voltage to the fire ticker. The ECM monitors the fuel heart electrical relay secondary tour for electric potential. If voltage drops downstairs a indisputable threshold, it will set DTC P0231, which is defined as "Low Voltage Fuel Pump Inessential Circuit."

What are the communal causes of code P0231 ?

Depending on year, hit, and model, DTC P0231 English hawthorn take number of causes. Here are some of the about common.

  • Relay – If the fuel pump relay is faulty, no voltage will tour to the fuel ticker Oregon monitor.
  • Rule Price – If in that location is legal injury to the harness going to the fuel ticker, IT can cause excessive resistance (corrosion), an subject circuit (broken wire), an intermittent open circuit (partly-broken cable), operating theatre a short to ground (contacting the body or chassis).
  • Feedback Tour – If at that place is an open circuit or corroding in the monitor circle to the ECM, the ECM won't see fire pump operation and will command the relay "off."
  • Inertia Switch – The inertia switch opens the fuel ticker circuit, in case of an accident, to prevent the fuel pump from mayhap dumping fuel onto the fomite and the basis. This is a fire-prevention measure. If the inertia change over has been activated, even past a small impact, IT could interrupt power flowing through the fuel ticker and to the ECM proctor.

What are the symptoms of code P0231 ?

Depending on the nature of the defect and the failure mode, the MIL (malfunction pilot light) will illuminate, but you may or English hawthorn not notice any drivability symptoms. The engine whitethorn not get down, or get-go then stall. Concurrent DTCs Crataegus laevigata include fuel system lean or miss codes, if the fuel heart is not operating at chockful capacity.

How do you troubleshoot code P0231 ?

A circuit low voltage indicates there is a trouble in the circle, not necessarily in the sensing element operating theater actuator, in this case the fuel ticker. Do not jump to replace anything unless it has been dependable and found inaccurate. For example, replacing the fuel pump will not solve this problem unless the fire heart is shorted internally. Therein guinea pig, the ECM is expecting to see at to the lowest degree 10.5 V when the pump is commanded on, but isn't. You'll need a DMM (digital multimeter) and an EWD (electrical wiring diagram) to name and repair this problem.

  • Voltage Check – First, check that the battery has at the least 12.6 V with the locomotive engine off and at least 13.5 V with the engine running. Correct any problems here before proceeding.
  • Merge Check – Check the fuel pump fuse. If the fuse is blown, this English hawthorn signal a short circuit someplace in the system. Proceed with caution – simply replacing the conflate may leave in another blown fuse until you repair the short.
    • Low-set Circuit Check – With the fuel pump relay far, you should measure at least 4 Ω finished the pump to ground. If you measure <4 Ω, you'll have to uncovering and repair the short. Repeat the test with the fire pump disconnected.
      • If the clipped circuit persists, the short is somewhere between the relay and ground. Look for chafed wiring or poor aftermarket installations that may have caused the short-circuit.
      • If you get an open lap, >10 kΩ, the old short circle is in the pump. With the pump disconnected, measure resistance across the terminals. If you measure to a lesser degree 4 Ω, replace the pump.
    • Fuel Pump Relay Check – You can do this aside swapping information technology with a known-good electrical relay, such Eastern Samoa for the wipers Oregon headlights. Differently, you can bench-test information technology past powering the principal circuit and checking for resistance across the junior circuit.
      • If the relay trade works – you marked their original locations, right? – you can condemn the fuel pump electrical relay.

If the electrical relay swap doesn't work, arrange the relays back in their original positions.

A General Fuel Pump Relay and Monitor Circuit

A General Fuel Pump Relay and Monitor Circle

    • Electrical relay Inputs and Outputs Check – Two terminals of the fuel pump electrical relay should have power and ii of them attend ground.
      • Test for resistance to ground on the secondary (fire ticker) circuit, which should measure at least 4 Ω to 6 Ω. Go back to the short section to a higher place.
      • The primary circuit is grounded by the Electronic countermeasures, so you should check for ground when you turn the key to the "Along" position or try to crank the locomotive engine. If you see none ground, see to it for an open circuit someplace between the relay and the ECM.
    • Fuel Pump Monitor Circuit – With the ECM disconnected, chit for persistence from the fire pump relay secondary circuit to the ECM. An subject electric circuit or excessive resistance here will horse around the ECM into thinking the fuel pump isn't acquiring enough voltage.
      • If you measure more than 0 Ω, condition for broken wires or corroding. Repair as requisite.

Codes Attached to P0231

  • P0230 Fire Pump Basic Circuit
  • P0231 Fuel Pump Auxiliary Circuit Depressed
  • P0232 Fuel Pump Collateral Circuit High
  • P0233 Fire Pump Secondary Circuit Periodic

BAT Team Discussions for P0231

  • 2000 Grand Don Marquis Will not bide running. Engine quits
    Update... I went to the parts store and they loaned Pine Tree State their code tester and here are the codes.. 1.) P0230 (fire pump Primary Circuit Malfunction) 2.) P0231 (Fuel Pump Secondary Circuit Voltage Low Not-MIL) 3.) P1121 (Throttle Situatio Sensor Inconsistent With MAF Sensor Pending. I changed the...