P0452
DTC P0452: FTP Sensor Circuit Low Voltage1. Check the vacuum lines of the FTP sensor for misrouting, leakage, breakage, or clogging.
Are the vacuum lines OK?
YES - Go to step 2.
NO - Repair or replace vacuum lines as necessary.
2. Reset the ECM/PCM.
3. Remove the fuel fill cap.
4. Turn the ignition switch ON (II).
5. Monitor FTP sensor voltage with the Honda PGM Tester, or measure voltage between body ground and ECM/PCM connector terminal A29.
Is there approx. 2.5 V ?
YES - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the FTP sensor and the ECM/PCM.
NO - Go to step 6.
6. Turn the ignition switch OFF.
7. Reinstall the fuel fill cap.
8. Disconnect the FTP sensor 3P connector.
9. Turn the ignition switch ON (II).
10. Measure voltage between FTP sensor 3P connector terminals No.1 and No.2.
Is there approx. 5 V ?
YES - Go to step 11.
NO - Repair open in the wire between the FTP sensor and the ECM/PCM (C28).
11. Measure voltage between FTP sensor 3P connector terminals No.2 and No.3.
Is there approx. 5 V ?
YES - Replace the FTP sensor.
NO - Go to step 12.
12. Turn the ignition switch OFF.
13. Disconnect ECM/PCM connector A (32P).
14. Check for continuity between FTP sensor 3P connector terminal No. 3 and body ground.
Is there continuity?
YES - Repair short in the wire between the FTP sensor and the ECM/PCM (A29).
NO - Substitute a known-good ECM/PCM and recheck. If the symptom/indication goes away, replace the original ECM/PCM.