P0453

DTC P0453: Evaporative Emission Control System Pressure Sensor High Input

CIRCUIT OPERATION

- The ECM (terminal No. 114) supplies a 5 volts reference voltage to the fuel tank differential pressure sensor (terminal No. 3). The ECM (terminal No. 113) supplies a ground to the fuel tank differential pressure sensor (terminal No. 2).
- The ECM (terminal No. 112) receives a voltage signal proportional to the pressure in the fuel tank from the fuel tank differential pressure sensor (terminal No. 1).

TECHNICAL DESCRIPTION

- To determine whether the fuel tank differential pressure sensor is defective, the ECM monitors the fuel tank differential pressure sensor output voltage.
- The ECM judges if the fuel tank differential pressure sensor output voltage is normal.

NOTE:
In rare cases, this DTC may be also set under some fuel and driving conditions regardless of the fuel pressure sensor output voltage when the fuel system is clogged.

DESCRIPTIONS OF MONITOR METHODS

Fuel tank differential pressure sensor output voltage is out of specified range.

MONITOR EXECUTION

Continuous

MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)

- Evaporative emission purge solenoid monitor
- Evaporative emission ventilation solenoid monitor
- Fuel tank temperature sensor monitor
- Fuel level sensor monitor
Sensor (The sensors below are determined to be normal)

- Mass airflow sensor
- Barometric pressure sensor
- Intake air temperature sensor
- Engine coolant temperature sensor
- Accelerator pedal position sensor

DTC SET CONDITIONS

Logic Flow Chart (Monitor Sequence)

Check Conditions

- 2 seconds or more have passed since the starting sequence was completed.
- Remaining fuel level is 80 percent or less when the engine is started.
Judgement Criterion

- The fuel tank differential pressure sensor output voltage remains 4.8 volts or greater for 5 seconds.

FAIL-SAFE AND BACKUP FUNCTION

- None

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)

- Fuel tank differential pressure sensor failed.
- Open fuel tank differential pressure sensor circuit, or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tools:

- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: M.U.T.-III USB Cable
- MB991910: M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, check data list item 52: Fuel Tank Differential Pressure Sensor.

CAUTION:
To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK"
(OFF) position before connecting or disconnecting scan tool MB991958.

(1)Connect scan tool MB991958 to the data link connector.

(2)Disconnect hose E from the evaporative emission canister, and plug the hose.
(3)Turn the ignition switch to the "ON" position.
(4)Remove the fuel cap.
(5)Set scan tool MB991958 to the data reading mode for item 52, Fuel Tank Differential Pressure Sensor.

- Output voltage should be between 1,500 to 3,500 mV.

(3)Measure the voltage between terminal No. 2 and ground by backprobing.

- Voltage should be 0.5 volt or less.
(4)Turn the ignition switch to the "LOCK" (OFF) position.

Q. Is the measured voltage 0.5 volt or less?

YES Go to Step 6 .

NO Go to Step 3 .

STEP 3. Check harness connector D-21 at the fuel tank differential pressure sensor and harness connector B-10 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 4 .
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 7 .
STEP 4. Check for open circuit between fuel tank differential pressure sensor connector D-21 (terminal No. 2) and ECM connector B-10 (terminal No. 113).

NOTE:
Check harness after checking intermediate connector C-47. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection.
Then go to Step 7 .

Q. Is the harness wire in good condition?

YES Go to Step 5 .
NO Repair it. Then go to Step 7 .
STEP 5. Using scan tool MB991958, check data list item 52: Fuel Tank Differential Pressure Sensor.

(6)Connect the evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube by using fuel tank adapter (MLR-8382) and pressurize the fuel tank.

- The fuel tank pressure reading should increase.
(7)Turn the ignition switch to the "LOCK" (OFF) position. Then disconnect scan tool MB991958.
(8)Remove the evaporative emission system pressure pump (Miller number 6872A) and the fuel tank adapter (MLR-8382), and reinstall the fuel cap.
(9)Connect hose E to the evaporative emission canister.

Q. Is the sensor operating properly?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

NO Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 7 .

STEP 6. Check harness connector D-21 at the fuel tank differential pressure sensor and harness connector B-10 at ECM for damage.

Q. Is the harness connector in good condition?

YES Replace the fuel tank differential pressure sensor. Then go to Step 7 .
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 7 .
STEP 7. Test the OBD-II drive cycle.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0453 set?

YES Retry the troubleshooting.
NO The inspection is complete.