P2402 — Evaporative Emission System Leak Detection Pump Control Circuit High

OBD2 code P2402 flags a problem with the evaporative emission (EVAP) system (evaporative emission system leak detection pump control circuit high). The car is usually drivable while you plan the repair. Common culprits: faulty purge valve (canister purge solenoid), faulty vent valve or leak detection pump, cracked EVAP hoses or lines.

powertrain (engine/transmission)

Is it safe to drive?

Short-term driving is OK Safe to drive. EVAP faults affect emissions, not drivability — you can keep using the car while planning the repair. Fuel vapour smell is a reason to fix it sooner: vapours are flammable and harmful.

How to diagnose with an OBD scanner

Read the code and freeze frame Connect an OBD2 scanner, confirm P2402 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Check for companion codes and TSBs Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Inspect wiring and connectors Visually inspect the wiring harness and connectors related to the evaporative emission (EVAP) system for damage, corrosion, chafing or poor contact.
Subsystem check With the evaporative emission system leak detection pump control disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
Subsystem check Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
Subsystem check Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
Verify the repair Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2402 does not return.

Approximate repair cost

Repair cost depends on which component actually failed. Typical scenarios for P2402 (parts and labor, USD, independent shop rates): Replace the fuel cap: $20–$60; Replace the purge or vent valve: $120–$350; Replace the charcoal canister: $250–$700. Overall, fixing P2402 usually costs between $20 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.

Common questions

How do I diagnose P2402 myself?

Start with a scan: confirm P2402, save the freeze frame and note any companion codes. Then inspect the wiring and connectors related to the evaporative emission system leak detection pump control, and verify the suspect component against live data before buying parts.

Is it safe to drive with P2402?

Safe to drive. EVAP faults affect emissions, not drivability — you can keep using the car while planning the repair. Fuel vapour smell is a reason to fix it sooner: vapours are flammable and harmful.

What is the most common cause of P2402?

The most common causes are: faulty purge valve (canister purge solenoid), faulty vent valve or leak detection pump, cracked EVAP hoses or lines.

What does OBD2 code P2402 mean?

What are the symptoms of P2402?

Drivers most often notice: fuel smell near the car, especially after refueling, no noticeable driving symptoms in most cases, slightly worse fuel economy, difficulty refueling (nozzle clicks off).

What does P2402 mean?

P2402 (Evaporative Emission System Leak Detection Pump Control Circuit High) is stored when self-diagnostics detect abnormal readings or behaviour of the evaporative emission (EVAP) system. It belongs to the powertrain (engine/transmission) category.

“Circuit high” means the control module sees a voltage on the evaporative emission system leak detection pump control circuit that is above the expected range — typically close to battery voltage. Physically this points to a short to a power feed, a broken ground return, or a failed component pulling the signal line high.

This code does not appear from a single bad reading: the module must see the fault condition repeat under defined operating conditions before it turns on the warning light. The freeze frame captured with P2402 — engine load, rpm, temperature, speed — tells you exactly when the problem occurs, so reproduce those conditions when testing.

What causes P2402?

signal wire shorted to battery positive
open ground return of the evaporative emission system leak detection pump control
failed evaporative emission system leak detection pump control pulling the signal high
faulty purge valve (canister purge solenoid)
loose, damaged or wrong fuel cap
faulty vent valve or leak detection pump
small leak in the fuel tank or filler neck
saturated or damaged charcoal canister

Common symptoms of P2402

fuel smell near the car, especially after refueling
no noticeable driving symptoms in most cases
slightly worse fuel economy
difficulty refueling (nozzle clicks off)
Check Engine Light on

How to diagnose P2402

Connect an OBD2 scanner, confirm P2402 is stored, and save the freeze frame data — it shows engine conditions when the fault was detected.
Related codes often reveal the real root cause. Also check manufacturer technical service bulletins (TSB) for your make and model — many P0xxx issues have factory fixes or software updates. Search by VIN on the manufacturer site or nhtsa.gov.
Visually inspect the wiring harness and connectors related to the evaporative emission (EVAP) system for damage, corrosion, chafing or poor contact.
With the evaporative emission system leak detection pump control disconnected, measure signal voltage at the harness connector: a high reading with the component unplugged indicates a short to power in the harness; if it drops to normal, the component itself is faulty.
Check the fuel cap first — it is the most common cause; inspect the seal and tighten until it clicks.
Run an EVAP leak test (smoke test) to locate small leaks in hoses, canister and valves.
Clear the code, complete a full drive cycle including the conditions from the freeze frame, and confirm P2402 does not return.

How to fix P2402

Start with the cheapest and most common causes before replacing expensive parts:

Replace the fuel cap — $20–$60
Replace the purge or vent valve — $120–$350
Replace the charcoal canister — $250–$700

How much does it cost to fix P2402?

Repair cost depends on which component actually failed. Typical scenarios for P2402 (parts and labor, USD, independent shop rates):

Replace the fuel cap: $20–$60
Replace the purge or vent valve: $120–$350
Replace the charcoal canister: $250–$700

Overall, fixing P2402 usually costs between $20 and $700. An accurate diagnosis before buying parts saves money — the most expensive scenario is rarely the first one to check.