Subaru Impreza 2003 Service Manual page 1568

TIME LAG TEST
AUTOMATIC TRANSMISSION
6. Time Lag Test
A: INSPECTION
NOTE:
If the select lever is shifted while the engine is
idling, there will be a certain time elapse or lag be-
fore the shock can be felt. This is used for checking
the condition of the low clutch, reverse clutch, low &
reverse brake and one-way clutch.
• Perform the test at normal operating fluid tem-
perature 70 to 80°C (158 to 176°F).
• Be sure to allow a 1 minute interval between
tests.
• Make three measurements and take the average
value.
1) Fully apply the parking brake.
2) Start the engine.
Check the idling speed (A/C OFF).
3) Shift the select lever from "N" to "D" range.
Using a stop watch, measure the time it takes from
shifting the lever until the shock is felt.
Time lag: Less than 1.2 seconds
If "N" → "D" time lag is longer than specified:
• Line pressure too low
• Low clutch worn
• One-way clutch not operating properly
4) In the same manner, measure the time lag for
"N" → "R".
Time lag: Less than 1.5 seconds
If "N" → "R" time lag is longer than specified:
• Line pressure too low
• Reverse clutch worn
• Low & reverse brake worn
4AT-36