Output Speed Sensor (ABS signal)
WARNING: This page is about a different car, the 2006 Dodge Sprinter. However, it is still accessible from the selected car via links, so may be relevant.
The NAG1 transmission does not have an output shaft speed sensor. The TCM uses the ABS (Antilock Brake System) Wheel Speed sensor information, it receives over the CAN bus, to calculate the transmissions output shaft speed. The TCM monitors the ABS system for functionality and reports ABS speed sensor and communication DTCs, which will affect proper transmission operation.