FixVault

Possible Causes

Possible Causes 
(T378) OUTPUT SPEED SENSOR SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
(T14) OUTPUT SPEED SIGNAL CIRCUIT SHORT TO GROUND
(T14) OUTPUT SPEED SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
(T14) OUTPUT SPEED SIGNAL CIRCUIT SHORT TO VOLTAGE
OUTPUT SPEED SENSOR
INTERNAL TRANSMISSION WIRING
TRANSMISSION ELECTRO HYDRAULIC CONTROL MODULE (TEHCM)

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. See  DTC-Based Diagnostics/MODULE, Transmission Electronic Hydraulic Control (TEHCM) - Standard Procedure   .