it could be that sensor , i sent you the trouble tree to diagnostic if the sensor or wiring
2000 Honda Accord EX Sedan L4-2254cc 2.3L SOHC (VTEC) MFI
Select Print Option Complete Article Text Only Image(s) Only
DTC P0720: Problem in Countershaft Speed Sensor Circuit NOTE: Record all freeze data before you troubleshoot. 1. Check the countershaft speed sensor installation. Is the countershaft speed sensor installed properly? YES - Go to step 2. NO - Reinstall and rechecks 2. Disconnect the countershaft speed sensor 2P connector.
3. Measure countershaft speed sensor resistance at the sensor connector. Is the resistance 400 - 600 ohms? YES - Go to step 4. NO - Replace the countershaft speed sensor. 4. Disconnect PCM connector D (16P).
5. Check for continuity between body ground and the D10 terminal and D16 terminal individually. Is there continuity? YES - Repair short in the wires between the D10 and D16 terminals and the countershaft speed sensor. NO - Go to step 6. 6. Connect the countershaft speed sensor connector.
7. Measure the resistance between the D10 and D16 terminals. Is the resistance 400 - 600 ohms? YES - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good PCM and recheck. NO - Repair loose terminal or open in the wires between the D10 and D16 terminals and the countershaft speed sensor. NOTE: Honda Motors has extended the warranty on A/Ts and torque converters to 7 years or 100,000 miles for '00-'01 Accords, '99-'01 Odyssesys, and '00-'01 Preludes. For more information, see Service Bulletin 02-062 (January 5, 2007).