P0452
DTC P0452: Evaporative Emission System Pressure Sensor Low InputSystem Diagram:
Fuel Tank Differential Pressure Sensor Circuit Part 1:
Fuel Tank Differential Pressure Sensor Circuit Part 2:
CIRCUIT OPERATION
- The ECM (terminal 42) supplies a 5-volts reference signal to the fuel tank differential pressure sensor (terminal 3). The fuel tank differential pressure sensor (terminal 2) is grounded through the ECM (terminal 49).
- The fuel tank differential pressure sensor (terminal 1) returns a voltage signal to the ECM (terminal 93) that is proportional to the pressure in the fuel tank.
TECHNICAL DESCRIPTION
- The ECM monitors the fuel tank differential pressure sensor output voltage.
- The ECM determines whether the fuel tank differential pressure sensor signal voltage is within normal operating parameters.
DESCRIPTIONS OF MONITOR METHODS
Compare purge solenoid status with fuel tank differential pressure sensor output voltage.
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 level sensor monitor
- Fuel temperature sensor monitor
Sensor (The sensors below are determined to be normal)
- Volume airflow sensor
- Barometric pressure sensor
- Intake air temperature sensor
- Engine coolant temperature sensor
Logic Flow Charts (Monitor Sequence):
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Check Conditions:
- 2 seconds or more have passed since the starting sequence was completed.
Judgment Criterion
- The fuel tank differential pressure sensor output voltage remains 0.2 volt or less for 5 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 20. OBD-II Drive Cycle Pattern Lists
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CODE TO BE SET ARE:)
- Malfunction of the fuel tank differential pressure sensor.
- A damaged harness in the fuel tank differential pressure sensor circuit.
- Malfunction of the ECM.
OVERVIEW OF TROUBLESHOOTING
- DTC P0452 can be set by a faulty fuel differential pressure sensor or related circuit, or ECM failure.
- To check a system blockage, do a performance test which uses a mechanical vacuum gauge and scan tool MB991958 set on the fuel tank differential pressure sensor (TANK PRS SNSR 73). The mechanical gauge reading is used to verify scan tool MB991958 reading. A comparison of the mechanical gauge to scan tool MB991958 determines the problem in the system.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
- MB991658: Test Harness Set
STEP 1. Using scan tool MB991958, check data list item 73: 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 I from the evaporative emission canister, and plug the hose.
3. Set scan tool MB991958 to the data reading mode for item 73, Fuel Tank Differential Pressure Sensor.
- The fuel tank pressure reading on the scan tool should be -1.5 to 1.5 kPa (-0.443 to 0.443 inHg).
4. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube and pressurize the fuel tank.
- The fuel tank pressure reading should increase.
5. Turn the ignition switch to the "LOCK" (OFF) position. Then disconnect scan tool MB991958.
6. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
7. Connect hose I to the canister.
Q: Is the fuel tank pressure between -1.5 and 1.5 kPa (-0.443 and 0.443 inHg)?
YES: It can be assumed that this malfunction is intermittent. Go to Step 15.
NO: Go to Step 2.
STEP 2. Measure the signal voltage at fuel tank differential pressure sensor connector D-09.
1. Remove the rear seat assembly.
2. Remove the floor pan access panel.
3. Use special tool MB991658 to connect terminals 1,2 and 3 of the fuel tank differential pressure sensor connector D-09.
4. Turn the ignition switch to the "ON" position.
5. Remove the fuel cap.
6. Measure the voltage between connector D-09 terminal 1 and ground.
- The measured voltage should measure between 2.0 and 3.0 volts.
7. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 2.0 and 3.0 volts?
YES: Go to Step 3.
NO: Go to Step 7.
STEP 3. Measure the signal voltage at ECM connector C-119 by backprobing.
1. Do not disconnect ECM connector C-119.
2. Turn the ignition switch to the "ON" position.
3. Remove the fuel cap.
4. Measure the voltage between connector C-119 terminal 93 and ground by backprobing.
- The measured voltage should measure between 2.0 to 3.0 volts.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 2.0 and 3.0 volts?
YES: Go to Step 4.
NO: Go to Step 5.
STEP 4. Using scan tool MB991958, check data list item 73: 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 I 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 73, Fuel Tank Differential Pressure Sensor.
- The fuel tank pressure reading on the scan tool should be -1.5 to 1.5 kPa (-0.443 to 0.443 inHg).
6. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel tank filler tube and pressurize the fuel tank.
- The fuel tank pressure reading should increase.
7. Turn the ignition switch to the "LOCK" (OFF) position.
8. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
9. Connect hose I to the canister.
Q: Is the fuel tank pressure between -1.5 and 1.5 kPa (-0.443 and 0.443 inHg)?
YES: It can be assumed that this malfunction is intermittent. Go to Step 15.
NO: Replace the ECM. Go to Step 15.
STEP 5. Check intermediate connectors C-113, C-122 and D-35, and ECM connector C-119, and fuel tank differential pressure sensor connector D-09 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors in good condition?
YES: Go to Step 6.
NO: Repair or replace the faulty components. Go to Step 15.
STEP 6. Check the harness wire between ECM connector C-119 terminal 93 and intermediate connector D-09 terminal 1 for damage.
Q: Is the harness wire in good condition?
YES: This malfunction is intermittent. Go to Step 15.
NO: Repair the damaged harness wire. Go to Step 15.
STEP 7. Measure the 5-volts reference signal at fuel tank differential pressure sensor connector D-09.
1. Disconnect fuel tank differential pressure sensor connector D-09.
2. Use special tool MB991658 to connect terminals 1, 2 and 3 of connector D-09.
3. Turn the ignition switch to the "ON" position.
4. Measure the voltage between terminal 3 and ground.
- The voltage should measure between 4.9 and 5.1 volts.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?
YES: Go to Step 8.
NO: Go to Step 11.
STEP 8. Measure the return circuit voltage at fuel tank differential pressure sensor connector D-09.
1. Disconnect fuel tank differential pressure sensor connector D-09.
2. Use special tool MB991658 to connect terminal 3 of connector D-09.
3. Turn the ignition switch to the "ON" position.
4. Measure the voltage between terminal 2 and ground.
- The voltage should measure 0.5 volt or less.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measure voltage 0.5 volt or less?
YES: Go to Step 9.
NO: Replace the fuel tank differential pressure sensor. Go to Step 15.
STEP 9. Check intermediate connectors C-113, C-122 and D-35, and ECM connector C-117,C-119 and fuel tank differential pressure sensor connector for D-09 loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 10.
NO: Repair or replace the damage components. Go to Step 15.
STEP 10. Check the harness wire between ECM connector C-117 terminal 49 and fuel tank differential pressure sensor connector D-09 terminal 2 for damage.
Q: Is the harness wire in good condition?
YES: Replace the fuel tank differential pressure sensor. Go to Step 15.
NO: Repair or replace the harness wire. Go to Step 15.
STEP 11. Measure the 5-volts reference signal at ECM connector C-117 by backprobing.
1. Turn the ignition switch to the "ON" position.
2. Measure the voltage between connector C-117 terminal 42 and ground by backprobing.
- The measured voltage should measure between 4.9 and 5.1 volts.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.9 and 5.1 volts?
YES: Go to Step 12.
NO: Go to Step 14.
STEP 12. Check intermediate connectors C-113, C-122 and D-35, and ECM connector C-117 and fuel tank differential pressure sensor connector for D-09 loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connectors and terminals in good condition?
YES: Go to Step 13.
NO: Repair or replace the faulty component. Go to Step 15.
STEP 13. Check the harness wire between ECM connector C-117 terminal 42 and fuel tank differential pressure sensor connector D-09 terminal 3 for damage.
Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent. Go to Step 15.
NO: Repair or replace the harness wire. Go to Step 15.
STEP 14. Check ECM connector C-117 for loose, corroded or damaged terminals, or terminals pushed back in the connector.
Q: Are the connector and terminals in good condition?
YES: Replace the ECM. Go to Step 15.
NO: Repair or replace the damaged components. Go to Step 15.
STEP 15. Perform 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 20. OBD-II Drive Cycle Pattern Lists
2. Read the diagnostic trouble code (DTC).
Q: Is DTC P0452 set?
YES: Go to Step 2.
NO: The procedure is complete.