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DTC P0452 (TNKP_Low): EVAP Emission Control System Pressure Sensor Low Input

  1. Turn ignition off. Remove and reinstall fuel filler cap. Connect SSM. Select SSM function mode F43 to check pressure signal value sent from fuel tank pressure sensor. Turn ignition on. If SSM reads a value of less than -2.8 kPa, go to next step. If value is -2.8 kPa or more, system is normal. Check for intermittent open or short in wiring between fuel tank pressure sensor and ECM connector. Check for poor terminal contact in ECM, fuel pressure sensor or ECM. Repair as necessary.
  2. Turn ignition on. Using DVOM connected to chassis ground, backprobe ECM connector terminal No. 21. See appropriate wiring diagram in WIRING DIAGRAMS article. If voltage reading is 4.5 volts or more, go to next step. If voltage reading is less than 4.5 volts, wiggle ECM connector. If voltage reading changes to 4.5 volts or more, repair wiring or poor terminal contact to ECM. If voltage reading does not change, replace ECM.
  3. Backprobe ECM connector terminal No. 4. If voltage reading is less than .2 volt, go to next step. If voltage reading is more than .2 volt, set SSM to function mode F43. Check if value changes to more than -2.8 kPa when wiggling ECM connector. If value changes, repair wiring or poor contact in ECM connector. If value does not change when wiggling ECM connector, go to next step.
  4. Turn ignition off. Remove right rear quarter panel trim. Disconnect fuel tank pressure sensor connector. Turn ignition on. Check voltage between chassis ground and sensor wiring terminal No. 3. If voltage reading is 4.5 volts or more, go to next step. If voltage reading is less than 4.5 volts, check for open in wiring between ECM and fuel tank pressure sensor connector, or check for poor terminal contact.
  5. Turn ignition off. Disconnect ECM connector. Check resistance between ECM connector terminal No. 20 and fuel tank pressure sensor connector terminal No. 2. If resistance is one ohm or less, go to next step. If resistance is more than one ohm, check for open in wiring between ECM and fuel tank pressure sensor connector, or check for poor terminal contacts.
  6. Check resistance between fuel tank pressure sensor connector terminal No. 1 and chassis ground. If resistance is more than 500,000 ohms, check for poor terminal contact in fuel tank pressure sensor connector. If terminal contact is okay, replace fuel tank pressure sensor. If resistance is 500,000 ohms or less, check for short in wiring between ECM and fuel tank pressure sensor.
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