P0450
DTC P0450 EVAP. EMISSION SYSTEM-PRESSURE SENSOR/SWITCHComponent 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. The fuel tank pressure sensor is a component of the evaporative emission system.The Tank Pressure Sensor converts fuel tank pressure to a proportional analog voltage signal which is read by the engine controller for evaluation during execution of the Evaporative System Diagnostic. The Tank Pressure may be below atmospheric pressure (i.e. a vacuum) or above atmospheric pressure.The fuel tank pressure is used to measure the difference between the air pressure (or vacuum) in the fuel tank and the ambient air pressure. ECM/PCM supplies a 5-volt reference and a ground to the sensor, which allows the sensor's output voltage to range from 0.1 to 4.9 volts.
DTC DESCRIPTION
If the differential tank pressure change is over 17 lbf/sq.ft during 25.5 sec under low speed condition, ECM/PCM sets DTC
DTC Detecting Condition:
Specification:
Schematic Diagram (A/T):
Schematic Diagram (M/T):
MONITOR SCANTOOL DATA
1. Connect scantool to Data Link Connector (DLC).
2. IG "ON".
3. Select "Diagnostic Trouble Codes (DTCs)" mode, and then Press F4 (DTAL) to check DTC's information from the DTCs menu.
4. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions noted in the DTC detecting condition.
5. Read "DTC Status" parameter.
6. Is parameter displayed "History (Not Present) fault"??
NOTE:
- History fault : DTC occurred but has been cleared.
- Present fault : DTC is occurring at present time.
YES - Fault is intermittent caused by poor contact in the sensor's and/or ECM/PCM's connector or was repaired and ECM/PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
NO - Go to "Terminal & Connector Inspection" procedure
TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminal condition. 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 " Circuit Voltage Check " procedure.
CIRCUIT VOLTAGE CHECK
1. IG "OFF" and disconnect FTPS connector.
2. IG "ON" & ENG "OFF"
3. Measure voltage between terminal 1 of FTPS harness connector and chassis ground.
Measure voltage between terminal 2 of FTPS harness connector and chassis ground.
Measure voltage between terminal 3 of FTPS harness connector and chassis ground.
Specification: Terminal 1 Approx. 5 V
Terminal 2 Approx. 0 V
Terminal 3 Approx. 5 V
4. Is the measured voltage within specification?
YES - Go to "Component inspection" procedure.
NO - Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure.
COMPONENT INSPECTION
1. Check FTPS
1. Key "ON".
2. Disassemble FTPS. (Don't disconnect FTPS connector.)
3. Connect the vacuum gauge.
Specification:
4. Measure the output voltage with using the vacuum gauge.
Caution: Be careful while you do this procedure. FTPS would be damaged if you apply vacuum excessively.
5. Is the measured voltage within specification?
YES - Substitute with a known-good ECM/PCM and check for proper operation. If the problem is corrected, replace ECM/PCM and then go to "Verification of Vehicle Repair" procedure.
NO - Substitute with a known-good FTPS and check for proper operation. If the problem is corrected, replace FTPS 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. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Clear the DTCs and Operate the vehicle within DTC Enable conditions in General information.
3. Are any DTCs present?
YES - Go to the applicable troubleshooting procedure.
NO - System is performing to specification at this time.