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Home >> Jeep >> 2009 >> Wrangler X, Automatic >> Repair and Diagnosis >> Transmission >> Automatic Trans >> (Transmission Control Module (TCM) - Electrical Diagnostics) >> DTC Troubleshooting >> P0721-Output Speed Sensor Circuit Performance >> Possible Causes
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Possible Causes

Possible Causes 
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT OPEN
(T13) SPEED SENSOR GROUND CIRCUIT OPEN
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORTED TO GROUND
(T13) SPEED SENSOR GROUND CIRCUIT SHORTED TO GROUND
(T14) OUTPUT SPEED SENSOR SIGNAL CIRCUIT SHORTED TO VOLTAGE
(T13) SPEED SENSOR GROUND CIRCUIT SHORTED TO VOLTAGE
OUTPUT SPEED SENSOR
POWERTRAIN CONTROL MODULE (PCM)

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