2001 Honda Odyssey "D" light flashing

Hi user110,

Thank you for the donation.

Honda strongly advises against flushing the transmission and the flushing is not going to solve the problem.

P1740 = Problem in 4th clutch transmission fluid pressure switch circuit.

I have emailed the diagnostic files to you.

Sorry that the email did not get through. My mail seems to work erratically.

Here are the diagnostic procedures.

DTC P1740: PROBLEM IN 4TH CLUTCH TRANSMISSION FLUID PRESSURE SWITCH CIRCUIT

1. Turn the ignition switch ON (II).

2. Measure the voltage between PCM connector terminals B19 and B20 or B22.
Is there battery voltage?

YES - Go to step 7.
NO - Go to step 3.

3. Turn the ignition switch OFF.

4. Disconnect PCM connector B (25P).

5. Disconnect the 4th clutch transmission fluid pressure switch connector.

6. Check for continuity between PCM connector terminal B19 and body ground.

Is there continuity?

YES - Repair short to ground in the wire between PCM connector terminal B19 and the 4th clutch transmission fluid pressure switch.

NO - Disconnect the 4th clutch transmission fluid pressure switch connector, and go to step 15.

7. Raise the front of the vehicle, and make sure it is securely supported.

8. Set the park brake, and block the rear wheels securely.

9. Start the engine, then shift to the D position and let the wheels spin in 4th gear for more than 5 seconds.

10. Measure the voltage between PCM connector terminals B19 and B20 or B22.

Is there about 0 V?

YES - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known good PCM and recheck.

NO - Go to step 11.

11 .Turn the ignition switch OFF.

12. Disconnect the 4th clutch transmission fluid pressure switch connector.

13. Turn the ignition switch ON (II).

14. Measure the voltage between the 4th clutch transmission fluid pressure switch connector terminal and body ground.

Is there battery voltage?

YES - Go to step 15.
NO - Repair open in the wire between the 4th clutch transmission fluid pressure switch and the PCM.

15. Measure the resistance between the 4th clutch transmission fluid pressure switch connector terminal and body ground.

Is the resistance 10 MÃ © or more?

YES - Check for loose terminal fit in the PCM connectors. If necessary, substitute a known-good PCM and recheck.

NO - Replace the 4th clutch transmission fluid pressure switch.