A-604 ULTRADRIVE TRANSAXLE
In 1989, the A-604 4-speed, electronic transaxle was introduced; it is the first to use fully adaptive controls. The controls perform their functions based on real time feedback sensor information. Although, the transaxle is conventional in design, functions are controlled by its ECM.
Since the A-604 is equipped with a learning function, each time the battery cable is disconnected, the ECM memory is lost. In operation, the transaxle must be shifted many times for the learned memory to be re-input to the ECM; during this period, the vehicle will experience rough operation. The transaxle must be at normal operating temperature when learning occurs.
- Maintain constant throttle opening during shifts. Do not move the accelerator pedal during upshifts.
- Accelerate the vehicle with the throttle 1 / 8 - 1 / 2 open.
- Make fifteen to twenty 1st-2nd, 2nd-3rd and 3rd-4th gear upshifts. Accelerating from a full stop to 50 mph (80 km/h) each time at the aforementioned throttle opening is sufficient.
- With the vehicle speed below 25 mph (40 km/h), make 5-8 wide open throttle kickdowns to 1st gear from either 2nd or 3rd gear. Allow at least 5 seconds of operation in 2nd or 3rd gear prior to each kickdown.
- With the vehicle speed greater than 25 mph (40 km/h), make 5 part throttle-to-wide open throttle kickdowns to either 3rd or 2nd gear from 4th gear. Allow at least 5 seconds of operation in 4th gear, preferably with load throttle prior to performing the kickdown.