DTC P0451 - Fuel Tank Pressure Sensor Signal Not Valid
- Install scan tool. Start engine and check if DTC P0451 is present. If DTC is present, go to next step. If DTC is not present, problem is intermittent. See INTERMITTENTS in TESTS W/O CODES article.
- Turn ignition off. Disconnect fuel tank pressure sensor harness connector, located near left rear suspension. Turn ignition on. Check voltage between fuel tank pressure sensor harness connector terminal No. 3 and ground. See appropriate wiring diagram in WIRING DIAGRAMS article. Voltage reading should be 4.8-5.2 volts. If voltage reading is as specified, go to next step. If voltage reading is not as specified, check circuit between terminal No. 3 and ECM.
- Turn ignition off. Disconnect ECM harness connector. Check for continuity between fuel tank pressure sensor harness connector terminal No. 1 and ECM harness connector terminal No. 76. If continuity is present, go to next step. If continuity is not present, check circuit between fuel tank pressure sensor and ECM.
- Check for continuity between fuel tank pressure sensor harness connector terminal No. 2 and ECM harness connector terminal No. 71. Continuity should be present. If continuity is present, replace fuel tank pressure sensor, then go to next step. If continuity is not present, check circuit between fuel tank pressure sensor and ECM.
- Reconnect ECM and fuel tank pressure sensor harness connectors. Clear DTC. See CLEARING CODES under Self Diagnostic System section. Retest system. If DTC resets, replace ECM.