A/T Controls Troubleshooting Guide

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




Step 1: Self-diagnostic System Inspection
Check for service code(s) memorized in the powertrain control module (transmission) by using the EC-AT Tester or Self-Diagnosis Checker. On-Board Diagnostics

NOTE: Service code(s) can also be checked by observing the flashing sequence of the HOLD indicator lamp. Service Code Number




Step 2: Electric Signal Inspection
Check the signals to/from the powertrain control module (transmission) with the EC-AT Tester. Electrical Signal Inspection

NOTE: Signals can also be checked by checking the powertrain control module (transmission) terminal voltages with the Engine Signal Monitor or a voltmeter.




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




Step 4: Road Test

NOTE: For correct testing, the vehicle speed, engine speed, throttle opening (throttle position sensor voltage), and gear position should be checked with the powertrain control module (transmission).

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