Fuel System > Engine Control System > P0453 Evaporative Emission System-Pressure Sensor High Input

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 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

Checking output signals of fuel tank pressure sensor under detecting condition, if the tank pressure is higher than threthold, PCM sets P0453. MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

•	Detects short to high voltage

•	Poor connection

•	Short to battery in signal Cirucit

•	Faulty FTPS

•	Faulty PCM

EnableConditions

•	Ignition ON

Threshold value

•	Raw Tank Pressure > 4.915V

DiagnosisTime

•	Continuous

MIL On Condition

•	2 driving cycles

Specification

Pressure(kPa)	Output Voltage(V)
-3.75	4.5
0	1.5
1.25	0.5

Schematic Diagram

Monitor DTC Status

Check DTC Status

(1)	Connect scantool to Data Link Connector(DLC).

(2)

IG "ON".

(3)	Select "DTC" button, and then Press "DTC Status" to check DTC's information from the DTCs menu.

(4)	Read "DTC Status" parameter.

(5)

Is parameter displayed "Present fault"?

	▶ Go to "Terminal and Connector inspection" procedure.
	▶ 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, ending, corrosion, contamination, deterioration, or damage. Repair or replace 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 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.

Has a problem been found?

	▶ Repair as necessary and go to "Verification of Vehicle Repair" procedure
	▶ Go to " Ground Circuit Inspection " procedure.

Ground Circuit Insepction

■ Check open in harness

1.	IG Key "OFF".

2.	Disconnect FTPS connector.

3.	IG Key "ON".

4.	Measure the voltage between power terminal of FTPS harness connector and chassis ground.(Measurement "A")

Measure the voltage between power and ground terminals of FTPS harness connector.(Measurement "B")

Specification : Voltage difference between Measurement "A" and "B" is below 200mV.

Is the measured voltage within specification ?

	▶ Go to "Signal Circuit Inspection" procedure.
	▶ Repair contact reistance or open in harness and then go to "Verification of Vehicle Repair" procedure.

Signal Circuit Insepction

■ Check short to battery in harness

1.	IG Key "OFF".

2.	Disconnect FTPS connector and PCM connector.

Measure the resistance between signal and power terminals of FTPS harness connector.

Specification : Infinite

Is the measured resistance within specification ?

	▶ Go to "Component Inspection" procedure.
	▶ Repair short in signal circuit and go to "Verification of Vehicle Repair" procedure.

Component Inspection

■ Check FTPS

1.	IG "OFF" and connect scatool to DLC(Data Link Connector).

Monitor "FTPS" parameter on service data.

Specificaton :

Pressure(kPa)	Output Voltage(V)
-3.75	4.5
0	1.5
1.25	0.5

Is the "FTPS" parameter on the service data O.K ?

	▶ 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.
	▶ 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.	Connect scantool and select "DTC" button.

2.	Press "DTC Status" button and confirm that "DTC Readiness Flag" indicates "Completed". If not, drive the vehicle within conditions noted in the freeze frame data or enable conditions

3.	Read "DTC Status" parameter

Is parameter displayed "History(Not Present) fault"?

	▶ System performing to specification at this time. Clear the DTC
	▶ Go to the applicable troubleshooting procedure.