TCU - Fault Code Erasure

9233hyundai01

Group: TRANSAXLE


Number: 92-40-001


Date: MARCH, 1992


Model: ALL


Subject:
ERASING TCU FAULT CODES


This bulletin provides information about erasing fault codes memorized in the Transaxle Control Unit (TCU). To ensure accurate future diagnosis, it is important that all fault codes are erased from the TCU after a fault has been corrected.

There are two methods of forced erasing. The first of these two methods involves disconnecting the battery negative terminal or removing the relevant fuse for fifteen (15) seconds and then re-connecting the negative terminal or re-installing the fuse.

The alternative forced erasing method involves a unique procedure to erase fault codes from the TCU and requires the use of the over-drive switch located on the shift lever. This method can be used on all Hyundai automatic transaxles equipped with the power/economy mode switch feature.

NOTE:
The 1989 & 1990 Sonata automatic transaxle models were not equipped with this feature and fault codes are erased automatically when the ignition switch is turned off.

The procedures listed MUST BE FOLLOWED PRECISELY when using the over-drive switch method as a means of forced erasing.

FORCED ERASING: Using the over-drive switch

1. Turn the ignition switch off.

2. Connect the MUT to the diagnosis connector in the fuse box.

3. Connect the power source terminal of the MUT to the cigarette lighter socket.

4. Turn the ignition switch on.

5. Use the MUT to check for self diagnosis codes.

6. Repair the faulty part using the diagnosis chart.

7. Turn the ignition switch off.

8. Turn the ignition switch on without cranking.

9. Place the shift lever to "P" range.

10. Push the over-drive switch ON/OFF three times in three seconds.

11. Read the self diagnosis output and check for absence of trouble codes.