Here's the procedure I posted on
www.lcool.org a while back.
_______________________________________________
Timing Belt Warning Indicator Reset Procedure
For LandCruiser UZJ100, HZJ105 and HDJ100.
1. T-BELT MODE DISPLAY
a) With ignition turned ON, using the trip switch (select/reset button) change the display to ODO, and turn the ignition OFF
b) While pressing the trip switch, turn the ignition switch ON and hold it for 5 seconds.
c) Release the trip switch, then press the switch again within 5 seconds.
d) The digital display should change to T-belt mode. The initial display " 15 " (0,000km) is displayed (ie. 150,000km).
2. REWRITING REPLACEMENT VALUES
While in the T-Belt mode, each press of the trip switch will change the displayed value by 10,000km increments. Once " 20 " (200,000km) is reached the display reverts back to " 1 " (10,000km) again. Remember, this setting is the number of kilometres to be travelled before the light comes on next, and once reset this counter will start from zero.
I believe the timing belt interval for all the 100 series engine variants is 150,000km, but this should be checked against each different markets servicing recommendation. This being the case, you shouldn't need to change from the default setting of " 15 ".
Obviously for the US, the ODO is in miles, and I guess the T-Belt warning would be set in 10,000 mile intervals.
3. T-BELT WARNING RESET COMPLETION
a) After setting the replacement setting value, hold the trip switch ON for more than 5 seconds then release the switch.
b) Check that the display has now changed back to ODO and that the warning light has gone off when the engine is started.
NOTE: If the T-Belt mode is completed, even though the belt replacement has not been performed, the T-Belt warning IS reset.