P0454
DTC P0454 EVAP. EMISSION SYSTEM-PRESSURE SENSOR INTERMITTENTComponent Location:
GENERAL DESCRIPTION
The evaporative emissions system prevents hydrocarbon (HC) vapors from the fuel tank from escaping into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Canister Closing Valve (CCV) closes off the air inlet into the canister for leak detection of the evaporative emission system. The CCV also prevents fuel vapors from escaping from the canister. When the engine purges the HC vapors from the canister, the clean air comes into the canister through the canister air-filter and the CCV.
DTC DESCRIPTION
The ECM monitors pressure stability in the fuel tank by means of Fuel Tank Pressure Sensor (FTPS) for predetermined duration just before start the leakage monitoring to detect noise signal of pressure sensor. The ECM sets DTC P0454 the pressure fluctuation is bigger than predetermined threshold. If same error code is set in the next driving cycle, the ECM illuminates the MIL.
DTC Detecting Condition:
Specification:
Schematic Diagram:
MONITOR DTC STATUS
NOTE: If DTCs (or pending codes) relating to FTPS are present, do ALL REPAIRS associated with those codes before proceeding with this troubleshooting tree.
1. Start engine to normal operating temperature
NOTE: Evaporative Emissions Systems (EVAP) Leak Tests can be run by the Scan Tool. The tests are automated and provide either a pass-fail result or directions to check for DTCs.
2. Install scan tool and clear DTC
3. Perform "EVAP. LEAKAGE TEST" mode referring to enable conditions as below
NOTE:
EVAP. Leakage Test enable conditions
- Following conditions must be fulfilled to start the test.
1. Engine warm up at Idle Status
2. No relevant DTC
3. Fuel level is below 80%
4. Is DTC P0451 set again?
YES - Go to next step as below.
NO - Fault is intermittent caused by poor contact in the sensor's and/or ECM's connector or was repaired and ECM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness(es) and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?
YES - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO - Go to "Fuel Tank Pressure Sensor (FTPS) inspection" procedure.
COMPONENT INSPECTION
1. Ignition "ON" & Engine "OFF" .
2. Measure voltage between terminal 3 of the sensor harness connector and chassis ground (Do not disconnect FTPS harness connector)
Specification : Voltage increases proportionally with decreasing pressure (Approx. 2.5 V to 4.5 V)
3. Is voltage within the specification?
YES - Check for poor connection between ECM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
NO
- Check for cracks or damage in hose connecting canister and fuel pump. Repair or replace as necessary.
- Check for open or short in FTPS harness. Repair as necessary. If OK, test with a new FTPS and check for proper operation. If problem is corrected, replace FTPS and go to "Verification of Vehicle Repair" procedure.
VERIFICATION OF VEHICLE REPAIR
1. Reconnect all EVAP hardware that was previously disconnected
2. Start engine to normal operating temperature
NOTE: Evaporative Emissions Systems (EVAP) Leak Tests can be run by the Scan Tool. The tests are automated and provide either a pass-fail result or directions to check for DTCs.
3. Install scan tool and clear DTC
4. Perform "EVAP. LEAKAGE TEST" mode referring to enable conditions as below
NOTE:
EVAP. Leakage Test enable conditions
- Following conditions must be fulfilled to start the test.
1. Engine warm up at Idle Status
2. No relevant DTC
3. Fuel level is below 80%
5. Monitoring for (pending) DTC. Is the same DTC set?
YES - Go to the applicable troubleshooting procedure.
NO - System performing to specification at this time.