2010 Toyota FJ Cruiser Owners Manual - Page 191

2-4. Using other driving systems Manual transmission Before using the rear differential lock system. Stop the vehicle or reduce your speed to less than 5 mph (8 km/h). Depress the clutch pedal and shift the four-wheel drive control lever into LL to see if this is sufficient. If this has no effect, additionally use the rear differential lock system. Be sure to stop the wheels. Depress the clutch pedal. Press the RR DIFF LOCK switch. Slowly release the clutch pedal. After the rear differential is locked, the indicator will come on. 2 When driving Unlock the rear differential as soon as the vehicle moves. To unlock the rear differential, push the switch again.