What Does P023F Mean?
The ECM has detected an open circuit or malfunction in the secondary fuel pump circuit. The secondary fuel pump (often an in-tank or supplemental pump) is not responding to control signals. The driver may experience hard starting, fuel starvation at higher RPMs or load, engine stumbling, or a no-start condition depending on which pump is affected.
Safety Warning
This can cause engine stalling or inability to maintain adequate fuel pressure, especially under load. The engine may die at highway speeds. Do not drive the vehicle until the fuel system is verified to be operating correctly. Tow to a repair facility if the vehicle stalls or will not maintain speed.
Common Causes
35%
Failed secondary fuel pump motor
25%
Open or broken wiring in the secondary fuel pump circuit
20%
Blown fuel pump fuse or failed fuel pump relay
15%
Corroded fuel pump connector (especially in-tank connectors exposed to moisture)
5%
Faulty fuel pump driver module or ECM driver
Diagnostic Steps
1
Check the secondary fuel pump fuse and relay first. Swap the relay with a known-good identical relay. Verify the fuse with a test light on both sides of the fuse — a visual inspection alone can miss cracked fuse elements.
2
With the key on (engine off), listen for the secondary fuel pump priming — you should hear a brief 2-3 second hum. No sound indicates the pump is not receiving power or has failed.
3
At the fuel pump connector, measure voltage with the key on — you should see battery voltage (12-14V) during the prime cycle. If voltage is present but the pump does not run, the pump has failed internally.
4
If no voltage at the pump connector, backprobe the fuel pump driver module or relay output. Trace the circuit for open wiring — check for rodent damage, corrosion at underbody connectors, or broken wires near the fuel tank.
5
Measure fuel pump motor resistance at the connector — a good pump typically reads 1-5 ohms across the motor terminals. An open reading (OL) confirms a failed pump motor.
Estimated Repair Cost
$200 - $900
Parts + labor, varies by vehicle and location
The ECM has detected an open circuit or malfunction in the secondary fuel pump circuit. The secondary fuel pump (often an in-tank or supplemental pump) is not responding to control signals. The driver may experience hard starting, fuel starvation at higher RPMs or load, engine stumbling, or a no-sta...
The most common cause of P023F (Fuel Pump Secondary Circuit/Open) is: Failed secondary fuel pump motor
Typical repair costs for P023F range from $200 to $900, depending on the vehicle, location, and whether you do it yourself or go to a shop.
This can cause engine stalling or inability to maintain adequate fuel pressure, especially under load. The engine may die at highway speeds. Do not drive the vehicle until the fuel system is verified to be operating correctly. Tow to a repair facility if the vehicle stalls or will not maintain speed.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P023F to identify the root cause.
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Quick Info
Category
Powertrain
System
Fuel System
Difficulty
Type
Generic (SAE)
Recommended Tools
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