General Notes

A problem with the EC-AT may be caused by the engine, the EC-AT powertrain, the hydraulic control system, or the electronic control system.

When troubleshooting, therefore, begin with those points which can be inspected quickly and easily. The recommended troubleshooting sequence is described below.




Step 1: Self-diagnosis Function
Check for service code(s) memorized in the EC-AT control unit with the EC-AT Tester.
Initial Inspection and Diagnostic Overview




Step 2: Electric Signal Inspection
Check the signals to/from the EC-AT control unit with the EC-AT Tester.
Electrical Signal Inspection

NOTE: Signals can also be checked by checking the EC-AT control unit terminal voltages with a voltmeter.
EC-AT Control Unit




Step 3: Mechanical System Test
Check the engine stall speed, time lag, line pressure, and throttle pressure.
Mechanical System Tests




Step 4: Road Test

NOTE: For correct testing, the vehicle speed, engine speed, throttle opening (throttle sensor voltage), and gear position should be checked with the EC-AT Tester.

Check the shift point, shift schedule, and shift shock.
Road Test

If the 4 steps are are followed, the cause of the problem should be located.

Another guide to faster location of the causes of problems is the QUICK DIAGNOSIS CHART.
Quick Diagnosis Chart

In this chart, numbers are used to indicate the components that may be the cause of 28 possible problems.

It is necessary to check only those components indicated by numbers during each step of the troubleshooting process to locate the cause of the problem quickly.