Honda Models: All models with one-push start.
When you shift into Park and shut off the engine, does the power mode stay in ON or ACCESSORY? The culprit could be a misadjusted shift cable. If it’s not adjusted right, it puts pressure on the shift lever, keeping the park pin switch from opening. The power control unit needs the park pin switch position input to switch the power mode to VEHICLE OFF (LOCK).
To find and fix this problem, connect a scan tool and go to the ONE-PUSH START/PCU Data List. Look at the AT SHIFT POSITION P and AT SHIFT POSITION P-PIN. Shift into Park while keeping your foot on the brake pedal. Then, without pressing the release button, pull back on the shift lever (toward Reverse). The AT SHIFT POSITION P signal should read ON and the AT SHIFT POSITION P-PIN signal should read OFF.
Another test is to shift into Reverse while pressing the brake pedal. Then, press the release button and gently push the shift lever into Park. When it goes into Park, the AT SHIFT POSITION P signal should then read ON and the AT SHIFT POSITION P-PIN signal should read OFF.
If you don’t get the expected results from either of those tests, refer to the electronic service manual and adjust the shift cable.
Courtesy of Mitchell 1.