P0454
P0454 Evap. Emission System - Pressure Sensor Intermittent
Component Location
General Description
The evaporative emission control system prevents hydrocarbon vapors from escaping from the fuel tank into the atmosphere where they could form photochemical smog. Gasoline vapors are collected in the charcoal canister. The Fuel Tank Pressure Sensor (FTPS) is an integral part of the evaporative monitoring system. The ECM monitors the FTPS signal to detect vacuum decay and excess vacuum. The FTPS measures the difference between the air pressure inside the fuel tank and outside air pressure to check the purge control solenoid valve operation and for leak detection in the evaporative emission control system by monitoring pressure and vacuum levels in the fuel tank during the purge control solenoid valve operating cycles.
DTC Description
If the voltage difference between maximum and minimum of fuel tank pressures signal is out of the threshold value, the ECM determines that a fault exists and a DTC is stored.
DTC Detecting Condition
Schematic Diagram
Terminal and Connector Inspection
1. Many malfunctions in the electrical system are caused by poor harness 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 " Component Inspection " procedure.
Component Inspection
1. Check PCSV
(1) Ignition "OFF"
(2) Measure resistance between terminals "1" and "2" of the PCSV connector.
A. Specification: Approx. 31.7 Ohms (20°C(68°F))
(3) Connect Scantool and Perform ACTUATION TEST for PCSV with scantool
(4) Check that clicking sound can be heard by actuation test.
(5) Monitor the PCSV signal waveform and verify that the ground voltage is less than approx. 0.3V and the surge voltage is between 40 V and 60 V.
(6) Is the PCSV normal?
YES
- Go to "Check CCV" as below.
NO
- Substitute with a known - good PCSV and check for proper operation.
If the problem is corrected, replace PCSV and go to "Verification of Vehicle Repair" procedure.
2. Check CCV
(1) Ignition "OFF"
(2) Measure resistance between terminals "1" and "2" of the CCV connector.
A. Specification: Approx. 23 ~ 26 Ohms (20°C(68°F))
(3) Connect Scantool and Perform ACTUATION TEST for CCV with scantool
(4) Check that clicking sound can be heard by actuation test.
(5) Monitor the PCSV signal waveform and verify that the ground voltage is less than approx. 0.3V and the surge voltage is between 40 V and 60 V.
(6) Is the CCV normal?
YES
- Go to "Check FTPS" as below.
NO
- Substitute with a known - good CCV and check for proper operation.
If the problem is corrected, replace CCV and go to "Verification of Vehicle Repair" procedure.
3. Check FTPS
(1) Engine "ON"
(2) Measure voltage between terminal "3" of FTPS connector and chassis ground.
A. Specification : 2.4 ~ 2.6 V (at idle)
(3) Is the measured voltage within specifications ?
YES
- Go to "Check ECM" as below.
NO
- Substitute with a known - good FTPS and check for proper operation.
If the problem is corrected, replace FTPS and go to "Verification of Vehicle Repair" procedure.
4. Check ECM
(1) Ignition "OFF"
(2) Connect Scantool and Ignition "ON" & Engine "OFF"
(3) Select simulation function on scantool.
(4) Simulate voltage at terminal "3" of FTPS signal connector.
A. Specification : 2.4 ~ 2.6 V(at idle)
(5) Does the signal value of FTPS change according to simulation voltage ?
YES
- 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.
NO
- Substitute with a known-good ECM and check for proper operation. If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.
Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs.
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Monitor that all readiness test have been verified as " Complete "
5. Are any DTCs present ?
YES
- Go to the applicable troubleshooting procedure.
NO
- System is performing to specification at this time.