Transmission Control Systems: Service Precautions

PRECAUTIONS BEFORE SERVICE
1. If the battery positive voltage is low, diagnostic trouble codes will not be output. Accordingly, check the battery before carrying out inspection.
2. If the battery is disconnected or if the engine control module connector is disconnected, the diagnostic trouble code memory will be erased.
Accordingly, the battery should not be disconnected until reading of the diagnostic trouble codes has been completed.