P0453

DTC P0453 EVAP. EMISSION SYSTEM-PRESSURE SENSOR HIGH INPUT






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 PCM 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 sensor output voltage is higher than 3.5 V, the PCM determines that a fault exists and a DTC is stored.

Schematic Diagram:

TERMINAL&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 " Signal Circuit Inspection " procedure.

SIGNAL CIRCUIT INSPECTION
1. Check for short to battery in harness
1. Ignition "OFF"
2. Disconnect FTPS connector.




3. Measure resistance between terminal 3 and "1" of FTPS harness connector.

Specification : Approx. below 1 Ohm

4. Is the measured resistance within specifications?

YES: Go to " Component Inspection" procedure.

NO:
- Check for short to ground in harness.
- Repair or replace as necessary and then, go to "Verification of Vehicle Repair" procedure.

COMPONENT INSPECTION
1. Ignition "OFF"
2. Disconnect Fuel Tank Pressure Sensor connector.
3. Measure resistance between terminal 1 & 3 of FTPS connector (To component Side)




4. Measure resistance between terminal 1 & 2 of FTPS connector (To component Side)

Specification :
Terminal 1 & 3 ; Approx. 1.1 kOhm
Terminal 1 & 2 : Approx. 5.8 kOhm

5. Is the measured resistance within specifications ?

YES: Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and 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 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.