P0452
Emission Control System - Troubleshooting - P0452Component 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 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
PCM sets DTC P0452 if the PCM detects signal voltage lower than the possible range of a properly operating FTPS.
DTC Detecting Condition:
MONITOR DTC STATUS
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Press F5(INFO) to select DTC information from the DTCs menu.
3. Confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
4. Read "DTC Status" parameter.
5. Is parameter displayed "History(Not Present) fault"?
NOTE:
1. History (Not Present) fault : DTC occurred but has been cleared.
2. Present fault : DTC is occurring at present time.
YES - Fault is intermittent, caused by poor contact in the sensor s and/or PCM s connector or was repaired and PCM 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.
NO - Go to next step.
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 "Power Supply Circuit Inspection" procedure.
POWER SUPPLY CIRCUIT INSPECTION
1. Ignition "OFF"
2. Disconnect FTPS connector
3. Ignition "ON" & Engine "OFF".
4. Measure voltage between terminal 3 of the FTPS harness connector and chassis ground.
Specification : Approx. 5 V
5. Is voltage within the specification?
YES - Go to "Signal Circuit Inspection" procedure.
NO - Check for a open in the power supply circuit. Repair as necessary and go to "Verification of Vehicle Repair" procedure.
SIGNAL CIRCUIT INSPECTION
1. Check for open in signal circuit.
1. Ignition "OFF".
2. Disconnect PCM connector.
3. Measure resistance between terminals 1 of the FTPS harness connector and 33 of the PCM harness connector.
Specification : Approx. 0 Ohm
4. Is resistance within the specification?
YES - Go to next step.
NO - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
2. Check for short to ground in signal circuit
1. Measure resistance between terminal 1 of the FTPS harness connector and chassis ground
Specification : Infinite
2. Is resistance within the specification?
YES - Go to next step.
NO - Repair as necessary and go to "Verification of Vehicle Repair" procedure.
FUEL TANK PRESSURE SENSOR INSPECTION
1. Ignition "ON" & Engine "OFF".
2. Disconnect the hose connecting fuel pump and FTPS.
3. Install vacuum pump in the hose at fuel pump side.
4. Apply vacuum pressure 3.75 cmHg (50 hPa) and 1.50 cmHg (20 hPa), and measure FTPS output voltage.
Specification : Voltage value will vary depending on variation in vacuum pressure
5. Is voltage within the specification?
YES - Check for poor connection between PCM 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
A. Check for cracks or damage in hose connecting canister and fuel pump. Repair or replace as necessary.
B. 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
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. Press F5(INFO) and confirm that "DTC Readiness Flag" indicates "Complete". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions.
3. Read "DTC Status" parameter.
4. Is parameter displayed "History(Not Present) fault"?
YES - System performing to specification at this time. Clear the DTC.
NO - Go to the applicable troubleshooting procedure.
Schematic Diagram:
