Error Code P0230 is defined as Fuel Pump Primary Circuit Malfunction. This indicates that the fuel pump primary circuit is experiencing a problem when it is commanded On/Off. This code is usually set when there’s an incorrect voltage detected by the PCM.

This trouble code is a generic trouble meaning, it applies to all vehicles equipped with OBD-II, or vehicles made since 1996 up to present. Specifications on the definition, troubleshooting and repairs vary from one make/model to another.


The PCM (powertrain control module, also referred as ECM or engine control module in some makes) controls and activates the fuel pump through a relay. As its name implies, the “relay” allows the transmission of higher amperage current to the fuel pump, and that current doesn’t have to go through the PCM.

Obviously, it’s always better to not have higher amperage current near the PCM, as it can create more heat and can cause PCM failure. The same principle applies to any relay – higher amperage is kept under the hood, away from sensitive areas.

The ‘relay’ is composed of two sides: the control (coil) and the switch (electrical contacts) side. The control side is the low amp side; it’s fed switch ignition feed (12V with key on) and a ground. The ground circuit on the other hand, is activated by the PCM driver when appropriate. When the fuel pump driver of the PCM activates the relay coil, the latter acts as an electromagnet, pulling the electrical contacts closed which completes the fuel pump circuit.

The closed switch allows voltage to flow to the fuel pump activation circuit, which activates the pump. Each time the key is turned on, the PCM will ground the fuel pump circuit for a few seconds, activating the fuel pump and providing pressure to the system. Until the PCM sees an RPM signal, the fuel pump will not be activated again.

The PCM’s driver is checked for faults; when activated the ground circuit (driver) should be low, and should be high or near battery voltage when deactivated. If the PCM sees voltage outside of the expected range, it activates the Error Code P0230.

Common Symptoms

As with other trouble codes, this error code illuminates the Check Engine light, which is it most obvious symptom. Other common symptoms include:

  • No start condition
  • Inoperative fuel pump
  • No fuel pump operation
  • Fuel pump running all the time with ignition on

Possible Causes

The most common cause for this code is when the fuel pump relay main power is low due to blown fuel pump fuse or fusible link, or shorted fuel pump or circuit. Other possible causes of Error Code P0230 include:

  • Open fuel pump control circuit
  • Control circuit with short to battery voltage
  • Chaffing on the harness causing any of the conditions above
  • Defective relay
  • Defective PCM

How to Check

As with most trouble codes this code is diagnosed with a scanner, which documents the freeze frame data to verify the problem, as well as the conditions of the vehicle when the problem was set.

The codes are then cleared to verify if it comes back.

Mechanics also check the fuel pump fuse or fusible link to see if they’re blown.

Then, they will test the voltage to the fuel pump relay primary circuit if they’re battery voltage.

Next, they will check for an open circuit of the fuel pump relay primary circuit resistance.

How to Fix

Repairs for this error code of course, are based on the results of the diagnosis. Some of the most common fixes however, include:

  • Repairing or replacement of the fuel pump fuse or fusible link
  • Replacement of the fuel pump (only)
  • Replacement of fuel pump relay

Error Code P0230 is caused by low voltage in main power circuit of fuel pump relay. The PCM reads this voltage to see whether it falls the lower than the voltage specified by the manufacturer.

A low battery voltage may trigger this code, especially if the voltage is lower than the specified level.

The fuel pump may be getting too much power which results to low voltage condition.

If error code P0231 or P0232 are present, follow the pinpoint test for trouble codes first to verify the failure on the secondary side of the fuel pump circuit.