2008 honda cr-v 5-speed automatic... push overdrive button on shifter and indicator light D3 comes on. What exactly is this telling me....that overdrive is engaged or that it's disengaged and

These do blink when activated to warn would be thieves.

If it means the same thing as my '04 accord it means that the transmission is in 3 speed mode ( no overdrive).

Over Drive..... Generally speaking, overdrive (OD) is the highest gear in the transmission. Overdrive allows the engine to operate at a lower rpm for a given road speed. This allows the vehicle to achieve better fuel efficiency, and often quieter operation on the highway. When it is switched on, an automatic transmission can shift into overdrive mode after a certain speed is reached (usually 70+ km/h [43+ mph] depending on the load). When it is off, the automatic transmission shifting is limited to the lower gears. For an automatic transmission, it is almost always best to select overdrive and allow the transmission to control engagement of the overdrive. (It may be necessary to switch it off if the vehicle is being operated in a mountainous area or when towing a trailer.) With a manual transmission, overdrive should usually be selected when the average speed is above 70 km/h (approx. 43 mph).

Overdrive is a very high final drive gear ratio, to save gasoline. But you should turn it off on hills or if you are going too slow. There should be an indicator light telling when it is on, but it should go off automatically if you are not in the highest regular gear, and if you are not going fast enough.

It will not do any damage to the trans if you press the button whilst you are on the move.Just don't do it at 80 mph.Around town you are completly safe to change from D to D3 and back again.Its like the auto is changing to a slightly lower gear.Thats all it does.Hope this helps

VTM4 LIGHT ON after gear was changed, but car drives smoothly and CHECK NENGINE light does not come on. Have diagnosed and was told nothing wrong with transmission. Please help

Well every gear has its limitations. I am not sure what the mph ranges for each gear are, but i've gotten to 60+ mph in 3rd gear. The only thing about driving on the freeway in 3rd gear is that it is alot less efficient mileage wise. Your turning more RPMS while on the freeway in 3rd gear so you burn up alot more gas.
Driving in D3 is driving in 3rd gear. It could burn up the tranny but it depends on the vehicle itself. It is not really made to do highways speeds in 3rd gear. It should be in 4th or 5th (OD)

This means your car has a built in "sports" shifter, which allows you to control the gears your car runs in manually, between D3 and D4 while its moving, its essentially an "overdrive" button. and if you read my posts, you'll discover that his light will soon become a huge pain.....

Hi!
This is not a code. Instead it is an indication that you are running the van in "overdrive off" mode.

Your van is equiped with a 5 speed automatic transmission. By running in overdrive off you are essentially running in 3rd gear, out of 5 gears. This will cause your van to run at a much higher engine speed, while not going very fast at all and consuming a lot more gas than normal.

You can deactivate this mode by:
1) start the van
2) Press the break pedal
3) Shift to 'D' (drive mode)
4) press the little button that is located on the left side of the shifter, under the shifter button.

If the light does not go out after pressing this button, you may need to take the van to your Honda dealership. Your van should still be under warranty as it is a 2007 model.

Good luck!