Toyota Repair: 99 toyota tacoma, engine rev, downshifting

Question
what does etc pwr mean

Answer
Extra Power. It doesn't give extra power. It changes the upshift & downshift mph targets of the transmission.

When accellerating they may upshift afew mph higher to let the engine rev another couple hundred rpm (Very little differance. Almost none in mot cases.).
The big change is how long the transmission will hold gears when decellerating & downshifting. With ETC power on, the transmission will let the engine rev up alot higher before downshifting to slow down.