Faulty PCM or EVAP monitoring processor internal failure; Corroded or damaged wiring in the EVAP monitor circuit; Poor electrical connection at the PCM or EVAP system components; Failed EVAP canister purge valve or vent valve affecting processor inputs; Software corruption or outdated PCM calibration; Ground fault or voltage supply issue to the PCM

DTC codes / P26xx · Computer and output circuits / P260F

P260FEVAP System Monitoring Processor Performance

Q: What does code P260F mean?

EVAP System Monitoring Processor Performance. P260F indicates that the powertrain control module (PCM) has detected an internal performance fault within the evaporative emission (EVAP) system monitoring processor, which is the dedicated logic circuit that runs the EVAP leak detection routines. The PCM sets this code when the processor's self-test fails or when its calculated results do not match expected values during the monitor's execution.

P260F indicates that the powertrain control module (PCM) has detected an internal performance fault within the evaporative emission (EVAP) system monitoring processor, which is the dedicated logic circuit that runs the EVAP leak detection routines. The PCM sets this code when the processor's self-test fails or when its calculated results do not match expected values during the monitor's execution.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Symptoms you may notice

Illumination of the malfunction indicator lamp (MIL) with no other noticeable symptoms
A slight fuel odor may be present if the EVAP system is not sealing properly during monitoring
In some cases, the vehicle may fail an emissions inspection due to the stored code
Rough idle or hesitation is possible if the processor fault disrupts other PCM functions
No driveability issues are common because the fault is internal to the monitoring logic

Common causes, most likely first

Faulty PCM or EVAP monitoring processor internal failure
Corroded or damaged wiring in the EVAP monitor circuit
Poor electrical connection at the PCM or EVAP system components
Failed EVAP canister purge valve or vent valve affecting processor inputs
Software corruption or outdated PCM calibration
Ground fault or voltage supply issue to the PCM

How to diagnose and fix it

Verify battery voltage and ground connections at the PCM and EVAP components
Inspect all wiring and connectors related to the EVAP system for damage or corrosion
Check for technical service bulletins (TSBs) or calibration updates for the PCM
Test the EVAP canister purge valve and vent valve for proper operation
Perform a smoke test to rule out any EVAP leaks that could affect processor readings
If all external components check out, reprogram or replace the PCM as needed

Processor Faults Often Misdiagnosed as Leaks

A P260F code can be set by a weak battery or charging system issue that causes the PCM to log a processor performance fault during low-voltage conditions.
Many technicians replace the PCM prematurely when the real cause is a shorted EVAP purge valve that draws excessive current and disrupts the processor's monitoring circuit.
The EVAP monitoring processor is integrated into the PCM on most vehicles, so a replacement PCM must be programmed with the correct calibration to avoid repeat codes.
Intermittent P260F codes often trace to a loose ground connection at the PCM or a chafed wire harness near the EVAP canister.
This code does not always indicate a hard failure; clearing it and performing a drive cycle may reveal if it was a one-time glitch caused by a voltage spike.

Can I keep driving with P260F?

The vehicle is generally safe to drive with P260F because it does not affect engine performance directly, but avoid long trips until the fault is diagnosed to prevent potential emissions system damage. Have the code addressed promptly to ensure the EVAP system can detect leaks properly.

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.