P0452
DTC P0452 EVAP. EMISSION SYSTEM-PRESSURE SENSOR LOW INPUTComponent 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
ECM sets DTC P0452 if the ECM detects signal voltage lower than the possible range of a properly operating FTPS.
DTC Detecting Condition:
Specification:
Schematic Diagram:
MONITOR DTC STATUS
1. Connect scan tool and select "Diagnostic Trouble Codes (DTCs)" mode.
2. Press F4 (DTAL) 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:
- History (Not Present) 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'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
NO - Go to next step as below
POWER CIRCUIT INSPECTION
1. Ignition "OFF".
2. Disconnect FTPS connector.
3. Ignition "ON" & Engine "OFF".
4. Measure voltage between terminal 1 of the FTPS harness connector and chassis ground.
Specification : Approx. 5 V
5. Is voltage within the specification?
YES - Go to next step as below
NO - Check for a open/short in the power supply circuit. Repair as necessary and go to "Verification of Vehicle Repair" procedure
SIGNAL CIRCUIT INSPECTION
1. Ignition "ON" & Engine "OFF".
2. Measure voltage between terminal 2 of the FTPS harness connector and chassis ground.
Specification : Approx. 5 V
3. Is voltage within the specification?
YES - Go to next step as below
NO - Repair 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 next step as below
COMPONENT INSPECTION
1. Reconnect FTPS connector.
2. Disconnect the hose connecting FTPS and fuel pump at FTPS side.
3. Install vacuum pump to the FTPS nipple.
4. Apply vacuum pressure 0.4 inHg(1.5 kPa) to 1.0 inHg(3.4 kPa) and measure FTPS output voltage between terminal 2 (back probe) of the FTPS harness connector and chassis ground.
Specification : Voltage increases proportionally with decreasing pressure (Approx. 2.5 V to 4.5 V)
CAUTION: Do not apply vacuum pressure less than 1.1 inHg(3.8 kPa)
5. 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 FTPS for contamination, deterioration, or damage. 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. Press F4 (DTAL) 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.