Electronic Controlled Automatic Transmission (ECAT)

1. Connect the appropriate EC-AT tester set.

2. Check self-diagnosed warning code in EC-AT control unit memory. This step checks major electronic components.

EC-AT Codes:

Throttle sensor and circuit
Turbine sensor and circuit
Speed sensor and circuit
All solenoid valves and circuits
EC-AT control unit

3. Check conditions surrounding the automatic transmission by performing the preliminary inspection as follows:

Check ATF level and condition
Engine oil and vacuum leakage
Selector lever position
Idle speed
Tire inflation pressure
Inhibitor switch

4. Check input and output signals to the EC-AT control unit.

5. Perform stall test to check friction element slipping, torque converter capacity.

6. Perform time lag test to check operation of the hydraulic control system:

Accumulators
Friction elements slipping
Regulating valves

7. Check oil pump and line pressure control by performing oil pressure test.

8. Road test vehicle. Check the following:

Shift points
Shift schedule
Kickdown
Shift shock
Lockup and overdrive inhibition