Possible causes
– Faulty Speed Sensor
– Speed Sensor harness is open or shorted
– Speed Sensor circuit poor electrical connection
– Speed Sensor harness is open or shorted
– Speed Sensor circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
– Speedometer improper reading
– Possible shifting problems
– Speedometer improper reading
– Possible shifting problems
P0721 HYUNDAI Description
The speed sensor detects the revolution of the idler gear parking pawl lock gear and emits a pulse signal. The pulse signal is sent to the Transmission Control Module (TCM) which converts it into vehicle speed.
HYUNDAI Technical Service Bulletins for P0721 code
2012 HYUNDAI ACCENT 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
2011 HYUNDAI AZERA 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
2011 HYUNDAI ELANTRA 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
2010 HYUNDAI SANTA FE 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
2011 HYUNDAI SONATA 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
2010 HYUNDAI TUCSON 103000 POWER TRAIN:AUTOMATIC TRANSMISSION
1999 HYUNDAI SONATA POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)
2001 HYUNDAI SANTA FE POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)
2001 HYUNDAI XG POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)
2003 HYUNDAI TIBURON POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM, PCM)