DTC P0734: 4th Gear Incorrect Ratio

WARNING: This page is about a different car, the 2013 Honda Odyssey, 2012 Honda Odyssey, and 2011 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot with the HDS, and review General Troubleshooting Information (see GENERAL TROUBLESHOOTING INFORMATION ).

Warm up the engine to normal operating temperature (the radiator fan comes on).
Make sure that the transmission is filled to the proper level, and check for fluid leaks.
Drain the ATF (see ATF REPLACEMENT ) through a strainer. Inspect the strainer for metal debris or excessive clutch material.
Does the strainer have metal debris or excessive clutch material?

YES -Replace the transmission, then go to step 11.

NO -Replace the ATF (see step 6 ), then go to step 4.
Measure the line pressure (see PRESSURE TEST ).
Is the line pressure within the service limit?

YES -Go to step 5.

NO -Replace the main valve body (ATF pump), the regulator valve body (regulator valve), or replace the transmission, then go to step 11.
Measure the 4th clutch pressure (see PRESSURE TEST ).
Is the 4th clutch pressure within the service limit?

YES -Go to step 6.

NO -Shift valves A, B, C, and D are stuck. Replace the main valve body and the regulator valve body, or replace the transmission, then go to step 11.
Turn the ignition switch to ON (II).
Clear the DTC with the HDS.
Test-drive the vehicle in 4th gear in D at speeds over 7 mph (12 km/h) for at least 12 seconds. Slowdown, and stop the wheels.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0734 indicated?

YES -Faulty 4th clutch. Replace the 4th clutch, or replace the transmission, then go to step 11.

NO -Go to step 10.
Monitor the OBD status for P0734 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?

YES -Intermittent failure, the system is OK at this time. If any other Pending or Confirmed DTCs were indicated in step 9, go to the INDICATED DTC'S TROUBLESHOOTING .

NO -If the HDS indicates FAILED, faulty 4th clutch. Replace the 4th clutch, or replace the transmission, then go to step 11. If the HDS indicates NOT COMPLETED, go to step 8.
Test-drive the vehicle in 4th gear in D at speeds over 7 mph (12 km/h) for at least 12 seconds. Slowdown, and stop the wheels.
Check for Pending or Confirmed DTCs with the HDS.
Is DTC P0734 indicated?

YES -Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor, the output shaft (countershaft) speed sensor, and the PCM, then go to step 1.

NO -Go to step 13.
Monitor the OBD status for P0734 in the DTCs MENU with the HDS.
Does the HDS indicate PASSED?

YES -Troubleshooting is complete. If any other Pending or Confirmed DTCs were indicated in step 12, go to the INDICATED DTC'S TROUBLESHOOTING .

NO -Check for poor connections or loose terminals between the input shaft (mainshaft) speed sensor, the output shaft (countershaft) speed sensor, and the PCM, then go to step 4. If the HDS indicates NOT COMPLETED, go to step 11.