What this code means
P1454 may indicate an EVAP system pressure or venting plausibility problem involving how the fuel tank pressure signal responds during EVAP operation.
What the vehicle may do
- The vehicle may have a check engine light.
- The vehicle can often drive normally even while the EVAP fault is stored.
- Fuel vapor system monitoring may not complete normally until the fault is corrected.
Possible fault areas
- Possible FTP sensor signal or connection concern.
- Possible restriction in the FTP sensor vent port or vent hose.
- Possible restriction in the EVAP canister vent hose, drain joint, or drain tube path.
- Possible EVAP canister vent shut valve corrosion or operation concern.
- Possible internal EVAP canister blockage.
Diagnostic path
Opening and setup
For this 2010 to 2015 Honda Civic with the 1.8 gas engine, P1454 may point to an EVAP pressure or venting plausibility problem during EVAP operation. The driver may only notice a check engine light, and the vehicle can often seem to run normally. Broadly, the fault area can involve the FTP sensor signal, the vent hoses and drain path, the canister vent shut valve, or a possible restriction inside the canister. Before getting into the test, save the freeze data and any on-board snapshot. If other codes are present, check what they mean first, then stay focused on proving the EVAP pressure and venting path for P1454.
Start with the FTP sensor at atmospheric pressure
Start with the basic EVAP pressure check. Turn the ignition switch to ON (II), clear the DTC with the HDS, then turn the ignition switch to LOCK (0). Remove the fuel fill cap and wait 1 minute. Turn the ignition switch back to ON (II), then look at FTP SENSOR in the HDS data list. With the cap off, the FTP sensor should read between －0.67 and 0.67 kPa, or between －0.2 and 0.2 inHg, or between －5 and 5 mmHg. The voltage equivalent is between 2.4 and 2.6 V. If the reading is in that range, move on and try to duplicate the failure. If it is not in that range, skip ahead to the FTP sensor vent hose restriction check.
Duplicate the EVAP monitor result
Install the fuel fill cap, clear the DTC again with the HDS, then start the engine. Let it idle with no load until the radiator fan comes on. Keep the transmission in P or N on an automatic, or neutral on a manual. Now watch EVAP PC DUTY in the HDS data list while holding engine speed at 3,000 rpm with EVAP PC DUTY at 20 % or more for at least 4 minutes. After that, let the engine idle and check the OBD status for P1454. If the HDS shows FAILED, the problem has been duplicated, so continue to the EVAP canister vent line check. If it shows PASSED, treat it like a possible intermittent. Use the on-board snapshot and repeat the conditions from when the code set, including fuel level, engine speed, vehicle speed, and outside temperature. If nothing shows up, check for poor connections or loose terminals between the FTP sensor and the ECM/PCM, and check for blockage in the FTP sensor vent port, FTP sensor vent hose, EVAP canister vent hose, and drain joint. If the status shows NOT COMPLETED, let the engine idle until the monitor gives a result.
Check the EVAP canister vent line
Once the failure is duplicated, clear the DTC, turn the ignition switch to LOCK (0), and disconnect the EVAP canister vent hose from the EVAP canister. Turn the ignition switch to ON (II), then check FTP SENSOR again in the HDS data list. If the reading comes back into the same normal range — between －0.67 and 0.67 kPa, between －0.2 and 0.2 inHg, between －5 and 5 mmHg, or between 2.4 and 2.6 V — look for a blockage in the EVAP canister vent hose or the drain tube joint, then verify the repair. If the reading is still outside that range, move to the canister vent shut valve operation check.
Check the canister vent shut valve
Turn the ignition switch to LOCK (0), remove the EVAP canister vent shut valve from the canister, and connect the 2P connector to the valve. Turn the ignition switch to ON (II), command EVAP CVS ON with the HDS, and check the valve operation. You are looking for a valve that is free of corrosion and operates properly. If it passes that check, the vent shut valve is considered OK, and the next move is the FTP sensor vent hose check. If it is corroded or does not operate properly, replace the EVAP canister vent shut valve, then verify the repair.
Check the FTP sensor vent hose, port, and canister path
Next, disconnect the vent hose from the FTP sensor and watch FTP SENSOR in the HDS data list. If the reading now falls into the normal range — between －0.67 and 0.67 kPa, between －0.2 and 0.2 inHg, between －5 and 5 mmHg, or between 2.4 and 2.6 V — check for a blockage in the FTP sensor vent hose, then verify the repair. If the reading is still outside that range, the FTP sensor vent hose is considered OK. Turn the ignition switch to LOCK (0), remove the FTP sensor from the EVAP canister with its connector still connected, then turn the ignition switch to ON (II) and check FTP SENSOR again. If the reading is now in range, the FTP sensor port is OK and the diagnostic path points to an internal blockage in the EVAP canister. Replace the EVAP canister, then verify the repair. If the reading is still not in range with the sensor removed and connected, replace the FTP sensor, then verify the repair.
Verify the repair
Keep verification separate from the testing. Turn the ignition switch to LOCK (0), install the parts in the reverse order of removal, turn the ignition switch to ON (II), reset the ECM/PCM with the HDS, and do the ECM/PCM idle learn procedure. Then monitor OBD status for P1454 with the HDS. If it shows PASSED, troubleshooting is complete. If any other pending or confirmed codes are still present, check what they mean and diagnose those separately. If it shows FAILED, go back to the first FTP sensor check and recheck the path instead of guessing. If it shows NOT COMPLETED, hold the engine at 3,000 rpm with EVAP PC DUTY at 20% or more until a result comes on. The takeaway is simple: P1454 is diagnosed by proving whether the FTP sensor returns to normal as you open sections of the EVAP vent path, then verifying the monitor after the repair. For more diagnostic training, visit stepdiagnostics.com.
Final check
Follow the pressure reading as the vent path is opened up, then verify that the P1454 monitor passes after the repair.
For more guided automotive diagnostics, visit STEP Diagnostics.
