Electronic Control System

WARNING: This page is about a different car, the 2002 Nissan Sentra, 2002 Infiniti G20, 2001 Nissan Sentra, and 2001 Infiniti G20. However, it is still accessible from the selected car via links, so may be relevant.

Transaxle is monitored by self-diagnostic systems of Engine Control Module (ECM) and TCM. Emission related on-board diagnostic system (OBD-II) is performed by TCM in combination with ECM. Malfunction is indicated by Malfunction Indicator Lamp (MIL) and is stored as a Diagnostic Trouble Code (DTC) in ECM, but not in TCM. A TCM self-diagnostic system malfunction is indicated by O/D OFF indicator. Malfunction is stored in TCM. Detected TCM items are overlapped with OBD-II self-diagnostic items.

The TCM receives a signal from the vehicle speed sensor, throttle position sensor or PNP switch, and provides shift control or lock-up control via transaxle solenoid valves. The TCM also communicates with the ECM by means of a signal sent from sensing elements used with the OBD related parts of the electronic control system for diagnostic purposes. The TCM is capable of diagnosing malfunctioning parts, while the ECM can store malfunctions in its memory. Input and output signals must always be correct and stable in the operation of the transaxle electronic control system. The transaxle electronic control system must be in good operating condition and be free of valve seizure, solenoid valve malfunction, etc.