Initial Inspection and Diagnostic Overview

AUTOMATIC TRANSMISSION FLUID (ATF) LEVEL AND CONDITION
1. Place vehicle on level floor.
2. Before removing dipstick, wipe all dirt from area around dip-stick.
3. With selector lever in "P" range and parking brakes applied, start engine.
4. Engine should be running at idle speed. Fluid should be at normal operating temperature [70-80°C (160-180°F)].
5. Move selector lever sequentially to every position to fill torque converter and hydraulic system with fluid, then place lever in N" Neutral position. This operation is necessary to be sure that fluid level check is accurate.
6. Check to see if fluid level is in "HOT" range on dipstick. It fluid is low, add automatic transaxle fluid until level reaches the "HOT" range.
Low fluid level can cause a variety of conditions because it allows pump to take in air along with fluid. Air trapped in hydraulic circuit forms bubbles which make fluid spongy.
Therefore, pressure will be erratic.

Improper filling can also cause fluid level too high. When transaxle has too much fluid, gears churn up foam and cause same conditions which occur with low fluid level, resulting in accelerated deterioration of automatic transaxle fluid. In either case, air bubbles can cause overheating, fluid oxidation, and varnishing, which can interfere with normal valve, clutch, and servo operation. Foaming can also result in fluid escaping from the transaxle vent where it may be mistaken for a leak.

Along with fluid level, it is important to check the condition of the fluid. When fluid smells burned, and is contaminated with metal bushing or friction material particles, a complete transaxle overhaul is needed. Be sure to examine fluid on dipstick closely. If there is any doubt about its conditions, drain out sample for double check. After fluid has been checked, seat dipstick fully to seal out water and dirt.