What does it mean?
This diagnostic code (DTC) is a generic powertrain code, meaning it applies to vehicles equipped with OBD-II. Although generic, specific repair steps may vary by make/model.
The fuel pump is activated by a relay controlled by the PCM. As its name suggests, a “relay” allows transmission of higher current to the fuel pump without that current having to pass through the PCM (Powertrain Control Module).
For obvious reasons, it’s preferable not to have higher current near the PCM. Higher current generates more heat and in case of failure, can cause PCM failure. This principle applies to any relay. Higher currents are kept under the hood, away from sensitive areas.
The relay essentially contains two sides. The “control” side which is essentially a coil and the “switch” side which is a set of electrical contacts. The control side (or coil side) is the low amp side. It’s powered by a switched ignition supply (12 volts with key on) and a ground. The ground circuit is activated by the PCM driver when needed. When the PCM fuel pump driver activates the relay coil, the coil acts as an electromagnet that closes the electrical contacts, completing the fuel pump circuit. This closed switch allows voltage to flow through the fuel pump activation circuit, activating the pump. Whenever the key is turned on, the PCM grounds the fuel pump circuit for a few seconds, activating the fuel pump and pressurizing the system. The fuel pump won’t be reactivated until the PCM sees an RPM signal.
The driver in the PCM is monitored for faults. When activated, the voltage of the drive or ground circuit should be low. When deactivated, the potential driver/ground voltage should be high or near battery voltage. If the PCM sees a voltage other than expected, P0230 may be set.
Symptoms
Symptoms of a P0230 DTC may include:
MIL illumination (malfunction indicator light)
No start condition
No fuel pump operation
Fuel pump runs continuously with ignition on
Causes
Potential causes of a P0230 code include:
Short to ground on control circuit
Open fuel pump control circuit
Short to battery voltage on control circuit
Harness chafing causing any of the above conditions
Faulty relay
Faulty PCM
Possible Solutions
Command the fuel pump on and off using a scan tool or simply by turning the ignition key on and off without starting the engine. If the fuel pump activates and deactivates, start the vehicle and measure current on the control circuit (ground) for a few minutes. It should be less than one amp and remain below one amp.
If not, replacing the relay is a good idea at this point. If the fuel pump doesn’t activate and deactivate, remove the relay and visually check for heat discoloration or loose terminals. If okay, install a test light between the ignition circuit supply and the ground driver terminals (if unsure, don’t attempt).
The test light should illuminate when the key is turned on or the fuel pump is activated. If not, ensure there’s voltage on one side of the coil (switched ignition supply). If voltage is present, repair the open or shorted circuit on the control ground circuit.