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Severity: Moderate Code type: Generic (all makes) ✱

P0232 Code: Fuel Pump Secondary Circuit High

The fuel pump feed wire has voltage on it when the engine computer has switched the pump off.

Unverified: this manufacturer-specific definition comes from a single source or varies by model. Confirm it with a brand-specific scan tool.

Safety first · Consult a professional

  • Fuel vapor is flammable. No smoking or open flames; work outdoors and fix fuel leaks before driving.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
Fuel Pump Secondary Circuit High
System
Fuel & Air Metering · Powertrain
Safe to drive?
With caution
Typical repair cost
$0–$500
DIY difficulty
Easy

P0232 is the mirror image of a dead pump circuit: the PCM commanded the pump off, but the voltage it monitors on the pump feed stayed high. Something is powering the pump without permission, most often relay contacts that have welded shut, a feed wire rubbing against another powered circuit, or a fuel pump driver module whose output is stuck on. The engine usually runs normally, so the clues are subtle: a pump that keeps humming after you switch off, a battery that goes flat overnight, or a pump that has run for hours with the car parked and worn itself out early. It also matters for safety, because the PCM shuts the pump off after a crash or a stall, and a stuck-on circuit defeats that protection.

Can I keep driving? The car will usually drive fine, but a pump that can't be switched off can drain the battery and keeps pushing fuel even after a stall or collision. Get it fixed soon, and pull the fuel pump fuse overnight if you hear the pump running with the key off.

How to read P0232

How to read P0232P10223324
  1. P Powertrain
  2. 0 Generic (SAE)
  3. 2 Fuel & air (injector circuit)
  4. 32 Specific fault

Symptoms

  • Fuel pump keeps humming after the key is turned off
  • Dead battery after the car sits overnight
  • Pump runs with the key on even when the engine is not cranking
  • Fuel smell around a parked car if there is also a small leak
  • Check engine light with no change in how the engine runs

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Fuel pump relay contacts welded or sticking closed 38%
  2. Pump feed wire chafed against a battery-powered circuit 18%
  3. Fuel pump driver module output stuck on 16%
  4. Incorrect relay type fitted, or a relay jumper left in place after testing 12%
  5. Aftermarket remote-start or alarm wiring spliced into the pump circuit 10%
  6. PCM monitoring input fault 6%

Diagnosis step by step

Diagnostic flow: P02321Listen with the key off2Pull the relay3Measure the feed with the relayremoved4Check for aftermarket wiring5Test the driver module6Run a parasitic draw check
  1. Listen with the key off

    Switch off, remove the key or step away with the smart key, and listen at the fuel filler or rear seat after about 10 seconds. A pump that is still running confirms something is feeding it without a PCM command.

  2. Pull the relay

    Remove the fuel pump relay while the pump is running with the key off. If the pump stops, the relay contacts are stuck; replace the relay with one of the correct type. If the pump keeps running with the relay out, the feed wire is getting power from somewhere else.

    Tools: Pliers

  3. Measure the feed with the relay removed

    Relay out, key off: measure between the pump output terminal in the relay socket (usually 87) and ground. It should read 0 volts. Any voltage means the feed wire is shorted to another powered circuit, so trace it toward the tank looking for melted or rubbed insulation.

    Tools: Multimeter

  4. Check for aftermarket wiring

    Look under the dash and near the relay box for added splices, T-taps or a remote-start or alarm module wired into the pump circuit. Poorly installed kill-circuit wiring is a common source of stray voltage on this wire.

    Tools: Flashlight, Screwdriver

  5. Test the driver module

    On vehicles with a fuel pump driver module, disconnect its command input with the key off. If its output to the pump still shows voltage, the module is stuck on internally and needs replacing.

    Tools: Multimeter

  6. Run a parasitic draw check

    If the battery has been going flat, measure battery drain with the car asleep; a running pump typically adds several amps. After the repair the draw should fall back to the normal sleep level, typically below about 50 milliamps.

    Tools: Multimeter

Where the parts are

Charging system and control modules – P02321234567
Charging system and control modules
  1. 1Battery
  2. 2Alternator
  3. 3Engine computer (ECM)
  4. 4CAN bus
  5. 5Transmission
  6. 6Wheel speed sensor
  7. 7High-voltage battery

Repair options & costs

RepairDIY?Estimated cost
Fuel pump relay replacement Yes $20–$90
Remove or correct aftermarket wiring No $80–$250
Repair shorted pump feed wire No $100–$350
Fuel pump driver module replacement Yes $150–$500
Battery recharge or replacement after repeated drain Yes $0–$250

Rough US estimates for parts and labor; shop rates vary by region. Not a quote.

Emissions / smog test impact

Will fail

A lit check engine light fails the OBD-II emissions check even though the engine runs normally. Replace the relay or repair the wiring, then drive a few days so the monitors are ready.

Frequently asked questions

Is it dangerous if the pump won't shut off?

It removes a safety layer. The PCM normally stops the pump when the engine stalls or after an airbag deployment, so fuel isn't pumped through a damaged line. With the circuit stuck on, that shutoff can't work, so don't put off the repair.

Could this be why my battery keeps dying?

Yes. An in-tank pump draws several amps, enough to flatten a healthy battery overnight. Pulling the pump fuse or relay while parked is a safe stopgap until the circuit is fixed.

Does running constantly damage the pump?

It adds hours of wear, and a pump running with the engine off circulates fuel without the normal flow pattern. Many pumps survive, but if it ran for days, a weakened pump later showing up as P0087 wouldn't be surprising.

Sources