P2402 indicates the powertrain control module (PCM) has detected a high voltage condition in the control circuit for the evaporative emission (EVAP) system leak detection pump. This pump pressurizes the EVAP system during self-tests to check for leaks. A high circuit voltage typically means the driver circuit inside the PCM is seeing voltage when it should be low, or the pump's internal windings are shorted to power.
The pump motor or its internal switching transistor can fail shorted, pulling the control circuit high whenever the PCM commands it off.
Chafed or pinched insulation on the control wire can contact a constant 12 V source, forcing the circuit high regardless of PCM output.
Corrosion or bent terminals can create unintended voltage paths that hold the control line high.
The low-side driver inside the PCM can fail in a way that leaves the output pulled high; this is uncommon but possible after the above items are ruled out.
Almost never. The vast majority of P2402 codes are caused by the leak detection pump itself or a wiring short to power. Replace the PCM only after the pump, wiring, and connectors have been thoroughly tested and eliminated.
No. A loose or missing gas cap typically sets large-leak codes such as P0455 or P0457. P2402 is strictly an electrical circuit-high fault in the pump control circuit.
Generally not. The EVAP leak detection pump operates only during key-off self-tests, so drivability is unaffected. The only practical effects are an illuminated MIL and an incomplete EVAP monitor for emissions testing.
Yes, short-term driving is safe. The fault does not affect engine operation or safety systems. Repair should be scheduled before the next emissions test or if the pump noise becomes audible.