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P0232 — Fuel Pump Secondary Circuit High

Generic OBD-II · all makesPowertrain (engine & transmission)

P0232 means the engine computer has detected an abnormally high voltage on the fuel pump’s secondary (monitor/feedback) circuit. This circuit reports whether the fuel pump driver/relay module is actually running the pump, so a continuously high reading usually indicates the feedback line is stuck near battery voltage or the driver is not switching properly.

Symptoms

What causes it — most likely first

1. Wiring or connector fault in the fuel pump monitor circuit

An open, short-to-voltage, corroded pin, or chafed wire in the secondary/monitor circuit can leave the feedback signal pulled high, which the PCM reads as a high-voltage fault.

2. Failed fuel pump driver/relay control module

If the module that switches and monitors the fuel pump does not ground or pulse the monitor line correctly, the PCM will see a constant high voltage and set P0232.

3. Fuel pump drawing excessive current

A failing or incorrect fuel pump that pulls too much current can overload or shut down the driver module, distorting or interrupting the monitor signal.

4. Faulty fuel pump relay or control circuit

A relay that is stuck, missing a control ground, or has a failing coil driver can keep the pump powered and the monitor circuit at a high level.

5. PCM failure

The PCM misreading the monitor circuit is possible but uncommon; it should only be considered after wiring, the driver/relay module, and the pump have been ruled out.

How it's diagnosed

  1. Visually inspect the fuel pump, driver/relay module, and PCM connectors for corrosion, damaged pins, chafing, or water intrusion.
  2. With the key on, measure voltage on the fuel pump secondary/monitor circuit and compare it to the specified pulsed or low-level signal; check for short-to-power or an open.
  3. Test or substitute the fuel pump driver/relay module and relay to confirm the monitor output switches correctly.
  4. Check fuel pump current draw and resistance; abnormally high current indicates a failing pump.
  5. Verify PCM command signals and grounds; suspect the PCM only if all wiring, the driver module, relay, and pump are proven good.

Code facts & related codes

SystemPowertrain (engine & transmission)
StandardizationSAE generic — identical on every make

Frequently asked

Can a bad fuel pump cause P0232?

Yes, but indirectly. A pump that draws excessive current can make the driver module drop out or distort the monitor circuit. However, wiring and driver-module faults are more common, so check those first.

Is it safe to drive with P0232?

No, not reliably. The fuel pump may stop without warning and cause the engine to stall or leave you with a no-start condition.

Do I need a new PCM for P0232?

Usually no. PCM failure is uncommon for this code. Most cases are caused by wiring, connectors, the fuel pump driver/relay module, or the fuel pump itself. Only consider the PCM after everything else is ruled out.

What is the difference between P0230, P0231, and P0232?

P0230 generally points to the primary fuel-pump control circuit, while P0231 and P0232 refer to the secondary monitor/feedback circuit being low or high, respectively.