P0722Powertrain
Powertrain · SAE
Output Speed Sensor Circuit No Signal
Meaning
The TCM receives no signal from the transmission output shaft speed sensor. The signal loss is total and persistent. Without this data the TCM cannot determine vehicle speed or correctly execute shift control and torque converter management strategies.
Common causes
- Output shaft speed sensor failed open-circuit
- Sensor connector unplugged or completely damaged
- Break in the sensor wiring harness
- Damaged or missing output shaft reluctor ring
- Internal TCM fault preventing signal reception
Symptoms
- Malfunction indicator lamp (MIL) permanently illuminated
- Transmission locked in limp/fail-safe mode
- Speedometer not functioning or reading zero
- Gear shifts completely absent or severely restricted
- ABS, traction control, or ESP generating related fault codes
Severity
Very high severity: total loss of the output speed signal renders transmission control inoperative and compromises the functionality of multiple vehicle safety systems.
What to do
- Read fault codes and verify whether the output speed value is zero or absent in live data
- Inspect the sensor connector for proper connection and absence of corrosion
- Check sensor wiring harness continuity with a multimeter (open-circuit test)
- Visually inspect the output shaft reluctor ring for presence and integrity
- Replace the sensor if open-circuit; repair the harness if broken; evaluate the TCM if all physical components are intact