Self-diagnosis system (A241E, A245E and A540H) — general information [Toyota Carina T190]

1. The self-diagnosis function is built into the electronic control unit of the automatic transmission. Using the upshift indicator, the system informs about a malfunction that has occurred in the automatic transmission. In addition, using this indicator, you can determine the code of the malfunction that has occurred.

Note: Warning signals and reading of fault codes are possible only when the overdrive switch is in the "ON" position. If the switch is in the "OFF" position, the indicator lamp lights without flashing.

a) If a malfunction occurs in the speed sensor, throttle position sensor or electromagnetic valves, the indicator will flash to warn the driver of the malfunction. However, if a malfunction occurs in the locking electromagnetic valve and the locking quality control electromagnetic valve, there will be no warning of the malfunction.

b) Error codes can be read by the number of flashes of the upshift indicator; to do this, short-circuit the "TE₁" and "E₁" terminals of the diagnostic connector.



c) The diagnostic system does not detect failure of the throttle position sensor and brake light switch, but they can be checked by measuring the voltage at the "TT" terminal of the diagnostic connector.





2. The fault code is stored in the control unit memory even after the engine is turned off. Clearing the control unit memory (reset codes after repairs) is done either by turning off the ignition and disconnecting the "EFI" fuse, or by disconnecting the automatic transmission and engine control unit connector.

Attention:

• - Low battery voltage may cause diagnostic failure. Therefore, check the battery before starting diagnostics.
• - use a voltmeter or ohmmeter that has a measurement scale limit of at least 10 kOhm/V.