P0452
DTC P0452: Evaporative Emission Control 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
- The fuel tank differential pressure sensor (terminal 1) returns a voltage signal to the ECM
TECHNICAL DESCRIPTION
- The ECM
- The ECM
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
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
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 Criteria
- 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 tank differential pressure sensor or related circuit, or ECM
- To check for 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 with the reading on scan tool MB991958 will locate a problem in the system.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A
- 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 H 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 in.Hg).
6. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel filler neck 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. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
9. Connect hose H to the canister.
Q: Is the fuel tank pressure between -1.5 and 1.5 kPa (-0.443 and 0.443 in.Hg)?
YES: It can be assumed that this malfunction is intermittent (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with intermittent Malfunction). Then go to Step 16.
NO: Go to Step 2.
STEP 2. Measure the signal voltage at fuel tank differential pressure sensor connector D-20.
1. Disconnect hose H from the evaporative emission canister side, and plug the hose.
2. Remove the rear seat assembly (Refer to Rear Seat).
3. Remove the floor pan access panel.
4. Use special tool MB991658 to connect terminals 1, 2 and 3 of the fuel tank differential pressure sensor connector D-20.
5. Turn the ignition switch to the "ON" position.
6. Remove the fuel cap.
7. Measure the voltage between connector D-20 terminal 1 and ground.
- The measured voltage should measure between 2.0 and 3.0 volts.
8. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel filler neck and pressurize the fuel tank.
- The fuel tank pressure reading should increase.
9. Turn the ignition switch to the "LOCK" (OFF) position.
10. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
11. Connect hose H to the canister.
Q: Is the measured voltage between 2.0 and 3.0 volts?
YES: Go to Step 3.
NO: Go to Step 6.
STEP 3. Measure the signal voltage at ECM
CAUTION: Connect the ground cable to the vehicle body before removing the ECM
1. Note that one of the ECM
2. Remove the ECM
3. Remove the ECM
4. Disconnect hose H from the evaporative emission canister, and plug the hose.
5. Turn the ignition switch to the "ON" position.
6. Remove the fuel cap.
7. Measure the voltage between connector C-111 terminal 82 and ground by backprobing.
- The measured voltage should measure between 2.0 and 3.0 volts.
8. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel filler neck and pressurize the fuel tank.
- The fuel tank pressure reading should increase.
9. Turn the ignition switch to the "LOCK" (OFF) position.
10. Disconnect the evaporative emission system pressure pump, and reinstall the fuel cap.
11. Connect hose H to the canister.
Q: Is the measured voltage between 2.0 and 3.0 volts?
YES: Go to Step 15.
NO: Go to Step 4.
STEP 4. Check intermediate connectors C-106, C-117 and D-22, and ECM
Q: Are the connectors in good condition?
YES: Go to Step 5.
NO: Repair or replace the faulty components (Refer to Harness Connector Inspection). Then go to Step 16.
STEP 5. Check the harness wire between ECM
Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with intermittent Malfunction). Then go to Step 16.
NO: Repair the damaged harness wire. Then go to Step 16.
STEP 6. Measure the 5-volt reference signal at fuel tank differential pressure sensor connector D-20.
1. Disconnect fuel tank differential pressure sensor connector D-20.
2. Use special tool MB991658 to connect terminals 1, 2 and 3 of connector D-20.
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 7.
NO: Go to Step 11.
STEP 7. Measure the return circuit voltage at fuel tank differential pressure sensor connector D-20.
1. Disconnect fuel tank differential pressure sensor connector D-20.
2. Use special tool MB991658 to connect terminals 1, 2 and 3 of connector D-20. 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 8.
NO: Replace the fuel tank differential pressure sensor. Then go to Step 16.
STEP 8. Check the sensor ground at ECM
CAUTION: Connect the ground cable to the vehicle body before removing the ECM
1. Note that one of the ECM
2. Remove the ECM
3. Remove the ECM
4. Turn the ignition switch to the "ON" position.
5. Measure the voltage between connector C-112 terminal 96 and ground by backprobing.
- The voltage should measure 0.5 volt or less.
6. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measure voltage 0.5 volt or less?
YES: Go to Step 15.
NO: Go to Step 9.
STEP 9. Check intermediate connectors C-106, C-117 and D-22, and ECM
Q: Are the connectors and terminals in good condition?
YES: Go to Step 10.
NO: Repair or replace the damage components (Refer to Harness Connector Inspection). Then go to Step 16.
STEP 10. Check the harness wire between ECM
Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with intermittent Malfunction). Then go to Step 16.
NO: Repair or replace the harness wire. Then go to Step 16.
STEP 11. Measure the 5-volt reference signal at ECM
CAUTION: Connect the ground cable to the vehicle body before removing the ECM
1. Note that one of the ECM
2. Remove the ECM
3. Remove the ECM
4. Turn the ignition switch to the "ON" position.
5. Measure the voltage between connector C-112 terminal 97 and ground by backprobing.
- The measured voltage should measure between 4.9 and 5.1 volts.
6. 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-106, C-117 and D-22, and ECM
Q: Are the connectors and terminals in good condition?
YES: Go to Step 13.
NO: Repair or replace the faulty component. Then go to Step 16.
STEP 13. Check the harness wire between ECM
Q: Is the harness wire in good condition?
YES: It can be assumed that this malfunction is intermittent (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with intermittent Malfunction). Then go to Step 16.
NO: Repair or replace the harness wire. Then go to Step 16.
STEP 14. Check ECM
Q: Are the connector and terminals in good condition?
YES: Replace the ECM
NO: Repair or replace the damaged components (Refer to Harness Connector Inspection). Then go to Step 16.
STEP 15. 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 H 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 in.Hg).
6. Connect an evaporative emission system pressure pump (Miller number 6872A) to the fuel filler neck 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 H to the canister.
Q: Is the fuel tank pressure between -1.5 and 1.5 kPa (-0.443 and 0.443 in.Hg)?
YES: It can be assumed that this malfunction is intermittent (Refer to How to Use Troubleshooting/Inspection Service Points - How to Cope with intermittent Malfunction). Then go to Step 16.
NO: Replace the ECM
STEP 16. 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.