P0722 Output Speed Sensor (OSS) Circuit No Signal

The P0722 – Output Speed Sensor (OSS) Circuit No Signal diagnostic trouble code (DTC) indicates that the transmission control module (TCM) is not receiving the expected signal from the transmission output speed sensor.

The Output Speed Sensor (OSS) measures the rotational speed of the transmission output shaft. The TCM uses this information to control gear shifts, calculate transmission ratios, monitor clutch slip, determine vehicle speed on some vehicles, and manage torque converter operation.

The key phrase in P0722 is “No Signal.” This means the TCM is not simply receiving an unstable signal. It is detecting that the expected output-speed signal is completely absent or below the level required for the TCM to recognize it.

What Does P0722 Mean?

In simple terms:

The transmission control module expects an output-speed signal, but it cannot detect one.

The basic operating sequence is:

Transmission output shaft rotates → OSS sensor detects rotation → Sensor generates a signal → TCM receives the signal → Signal is missing → P0722 is stored

The exact sensor design varies between vehicles.

Some systems use a magnetic or Hall-effect speed sensor, while others integrate the output-speed sensing element into an internal transmission speed-sensor assembly.

What Is the Output Speed Sensor?

The Output Speed Sensor (OSS) measures the rotational speed of the transmission's output shaft.

The TCM can compare output speed with other information, such as:

• Engine RPM

• Transmission input speed

• Selected gear

• Throttle position

• Vehicle speed

This allows the TCM to determine whether the transmission is operating as commanded.

The OSS signal is particularly important for calculating the actual transmission output speed.

Why Is Output Speed Important?

The TCM uses output-speed information for several functions.

It can help control:

• Gear changes

• Shift timing

• Gear-ratio calculations

• Transmission slip monitoring

• Torque converter clutch operation

• Vehicle-speed calculations

• Transmission protection strategies

If the TCM loses this signal completely, several transmission functions may be affected.

Symptoms of P0722

The symptoms depend on the vehicle and transmission design.

Possible symptoms include:

Harsh shifting

The transmission may shift harder than normal.

Delayed shifting

The TCM may hesitate before changing gears.

Erratic shifting

Gear changes may become unpredictable.

Transmission stuck in one gear

The transmission may enter a fail-safe strategy.

Limp mode

Transmission operation may be restricted.

Speedometer malfunction

On some vehicles, the OSS signal is used to determine vehicle speed.

Cruise control problems

Cruise control may be disabled when reliable vehicle-speed information is unavailable.

Transmission slipping

The TCM may have difficulty monitoring transmission behavior.

Incorrect gear selection

The transmission may select an inappropriate gear because output speed is unavailable.

Torque converter clutch problems

Torque converter lock-up may be disabled or altered.

Check Engine Light

The malfunction indicator lamp may illuminate.

What Causes P0722?

There are several possible causes.

Failed output speed sensor

The sensor may have completely stopped producing a signal.

Damaged OSS wiring

An open circuit can prevent the signal from reaching the TCM.

Shorted wiring

A short circuit can prevent the TCM from recognizing the sensor signal.

Loose connector

A disconnected or poorly seated connector can completely interrupt the signal.

Corroded terminals

Corrosion can increase resistance or prevent electrical contact.

Water intrusion

Moisture inside the connector can interfere with the sensor circuit.

Damaged reluctor or tone ring

The sensor needs a rotating target to generate or interpret the speed signal. Damage to this component can result in no usable signal.

Incorrect sensor installation

An incorrect sensor position or air gap can prevent proper signal generation.

Metal contamination

On certain magnetic sensor systems, excessive metal debris can interfere with sensor operation.

Internal transmission wiring fault

Some transmissions place the speed sensor and its wiring inside the transmission.

Power or ground problem

A sensor may fail to operate if its required power or ground is missing.

TCM wiring problem

The signal may be lost between the sensor and the TCM.

TCM failure

A TCM fault is possible, although it should generally be considered only after the sensor and circuit have been properly tested.

Can a Bad Output Speed Sensor Cause P0722?

Yes.

The OSS sensor itself is one of the first components to investigate.

If the sensor completely fails, the TCM may receive no output-speed information.

For example:

Output shaft rotating → Sensor should generate signal → No signal detected → P0722

A failed sensor may also cause related transmission symptoms because the TCM loses one of its important speed inputs.

Can Wiring Cause P0722?

Yes.

An open circuit is particularly relevant to a no-signal code.

Possible wiring problems include:

• Broken wire

• Open circuit

• Short to ground

• Short to voltage

• Damaged insulation

• Corroded terminals

• Loose connector

• Water intrusion

The wiring should be checked from the sensor all the way to the relevant control module.

Can a Bad Connector Cause P0722?

Yes.

A disconnected or poorly connected sensor plug can completely eliminate the signal.

Inspect for:

• Bent pins

• Corrosion

• Loose terminals

• Damaged locking mechanism

• Oil contamination

• Water intrusion

Sometimes the connector appears visually normal but the terminals no longer have sufficient contact pressure.

Can a Damaged Reluctor Cause P0722?

Yes.

The OSS sensor detects a rotating target, which may be a reluctor, tone wheel, or similar component.

If the target is:

• Broken

• Damaged

• Cracked

• Misaligned

• Missing teeth

• Incorrectly installed

the sensor may not produce a usable speed signal.

In this situation, replacing the sensor alone may not solve P0722.

Can Transmission Fluid Cause P0722?

Not usually as a direct cause.

However, on some transmissions, internal contamination can affect the speed-sensor environment.

Metal debris can interfere with certain magnetic sensors.

If the transmission fluid contains excessive metal particles, that may also indicate internal transmission wear that deserves further investigation.

Therefore, fluid condition can provide useful supporting information, but it should not automatically be blamed for P0722.

Can a Bad Ground Cause P0722?

Yes.

Some speed sensors require a reliable ground reference.

A poor ground can prevent the sensor from generating or transmitting a usable signal.

Check:

• Sensor ground

• Transmission ground

• Engine ground strap

• TCM ground

• Battery negative connection

Voltage-drop testing can be more useful than relying only on resistance measurements.

Can a Weak Battery Cause P0722?

Potentially, but it is not a primary cause.

Low or unstable voltage can interfere with electronic sensors and control modules.

If P0722 appears together with multiple unrelated electrical codes, check:

• Battery condition

• Charging system

• Battery terminals

• Grounds

• Module power supplies

A battery should not be replaced solely because P0722 is stored.

Can a CAN Bus Problem Cause P0722?

Yes, depending on the vehicle.

Some modern vehicles distribute transmission-speed and vehicle-speed information electronically through the CAN network.

If the TCM cannot receive required information because of a communication problem, it may interpret the condition as a missing speed signal.

Possible causes include:

• CAN-H wiring fault

• CAN-L wiring fault

• Connector problems

• Module power loss

• Module ground fault

• Network communication failure

• Faulty control module

If several communication DTCs appear alongside P0722, the communication network should be investigated.

Does P0722 Mean the Transmission Is Bad?

No.

This is an important distinction.

P0722 identifies a missing output-speed signal. It does not automatically indicate internal transmission damage.

The problem may be caused by:

Sensor → Connector → Wiring → Power/ground → Signal circuit → TCM

Only after these areas have been properly tested should internal mechanical transmission problems be considered.

Can P0722 Cause Incorrect Gear-Ratio Codes?

Yes.

The TCM uses output speed when calculating transmission ratios.

If output speed is unavailable, the TCM may not be able to correctly determine the actual gear ratio.

As a result, P0722 can potentially appear together with:

• P0729 – Gear 6 Incorrect Ratio

• P0730 – Incorrect Gear Ratio

• P0731 – Gear 1 Incorrect Ratio

• P0732 – Gear 2 Incorrect Ratio

• P0733 – Gear 3 Incorrect Ratio

• P0734 – Gear 4 Incorrect Ratio

When P0722 appears alongside multiple ratio codes, the missing OSS signal should be investigated before assuming that the transmission has several internal gear problems.

Can P0722 Cause Speedometer Problems?

Yes, on some vehicles.

The output-speed signal may be used to calculate vehicle speed.

If the signal disappears, the vehicle may experience:

• Speedometer reading of zero

• Incorrect speed reading

• Speedometer fluctuation

• Cruise-control cancellation

• Vehicle-speed-related warning lights

Other vehicles use a dedicated wheel-speed sensor system for vehicle speed, so the speedometer may continue working normally even when P0722 is present.

Can P0722 Affect Cruise Control?

Yes.

Cruise control requires reliable vehicle-speed information.

If the vehicle's speed information depends on the transmission output-speed signal, the system may disable cruise control when that signal disappears.

This is a safety strategy designed to prevent cruise control from operating with unreliable speed information.

Can P0722 Cause Limp Mode?

Yes.

A complete loss of output-speed information can be significant enough for the TCM to activate a protective strategy.

Depending on the transmission, the vehicle may experience:

• Fixed-gear operation

• Limited gear selection

• Harsh shifting

• Disabled torque converter clutch

• Reduced transmission performance

• Fail-safe operation

The exact behavior depends on the manufacturer's transmission-control strategy.

How Is P0722 Diagnosed?

Because P0722 indicates a complete lack of signal, diagnosis should concentrate on finding where the signal is being lost.

1. Scan all DTCs

Check for additional codes involving:

• Input speed sensor

• Output speed sensor

• Engine speed

• Gear ratios

• Vehicle speed

• CAN communication

• TCM

• ECM/PCM

Additional codes can significantly narrow the diagnosis.

2. Check freeze-frame data

Review the conditions when the code was stored.

Important information includes:

• Vehicle speed

• Engine RPM

• Selected gear

• Transmission temperature

• Engine temperature

• Throttle position

• Battery voltage

3. Check OSS live data

Monitor the output speed value using a suitable scan tool.

If the vehicle is moving but the scan tool shows:

OSS = 0 RPM

the missing output-speed signal becomes a strong suspect.

4. Compare OSS with vehicle speed

If the vehicle is clearly moving while the TCM reports no output speed, investigate the OSS circuit.

5. Inspect the sensor

Check for:

• Physical damage

• Incorrect installation

• Contamination

• Mounting problems

6. Inspect the connector

Check for corrosion, bent pins, loose terminals, and water intrusion.

7. Test wiring

Check for:

• Open circuits

• Short circuits

• Poor continuity

• Excessive resistance

8. Check power and ground

Verify the sensor has the required electrical supply and ground.

9. Inspect the reluctor or tone ring

If the electrical circuit tests correctly, inspect the mechanical target that the sensor reads.

10. Check transmission fluid when appropriate

Look for abnormal contamination or excessive metal debris.

Why Is Live Data Important for P0722?

Live data can confirm whether the TCM is actually receiving output-speed information.

For example:

Vehicle moving at 50 km/h → OSS reports 0 RPM

This indicates that the TCM is not seeing the expected output-speed signal.

If the OSS value suddenly becomes normal after moving the wiring harness or changing the connector position, an intermittent wiring problem may be present even though the stored code is P0722.

What If P0722 Appears Immediately After Starting the Vehicle?

If P0722 appears immediately, inspect the electrical circuit first.

Possible causes include:

• Completely failed sensor

• Disconnected connector

• Open circuit

• Missing sensor power

• Missing sensor ground

• TCM input problem

If the code appears only after the vehicle begins moving, the sensor or reluctor may be more strongly suspected.

What If P0722 Appears Only After the Vehicle Starts Moving?

This is an important clue.

The TCM cannot expect a meaningful output-speed signal while the output shaft is stationary.

The fault may therefore be detected only after the vehicle begins moving and the TCM expects the OSS signal to increase.

Possible causes include:

• Failed OSS sensor

• Damaged reluctor

• Incorrect sensor gap

• Sensor wiring problem

What If P0722 Appears When the Transmission Is Hot?

A sensor can fail after reaching operating temperature.

If the vehicle operates normally when cold but loses output-speed information when hot, investigate:

• OSS sensor

• Internal transmission wiring

• Connector

• Sensor mounting

Temperature-dependent electrical failures can be difficult to reproduce during a short inspection.

What If P0722 Appears During Acceleration?

Acceleration increases vibration and movement around the transmission.

If the code occurs specifically under acceleration, inspect:

• OSS wiring

• Connector

• Harness routing

• Transmission grounds

• Sensor mounting

A broken conductor can make contact at idle and lose contact when the transmission moves under load.

Can an Oscilloscope Diagnose P0722?

Yes.

An oscilloscope can determine whether the OSS sensor is producing the correct waveform.

Depending on sensor type, testing can reveal:

• No waveform

• Missing pulses

• Weak signal

• Incorrect waveform

• Electrical interference

• Irregular pulse pattern

If the sensor has power and ground but produces no output signal while the transmission output shaft is rotating, the sensor itself or its mechanical target becomes a major suspect.

Is P0722 a Serious Problem?

It can be.

The output-speed signal is important for transmission control.

A complete loss of this signal can cause:

• Incorrect shifting

• Limp mode

• Incorrect ratio calculations

• Speedometer problems

• Cruise-control cancellation

• Increased transmission stress

The vehicle should be diagnosed promptly, particularly if transmission operation has changed noticeably.

Can You Drive With P0722?

If the transmission still operates normally, a short trip to a repair facility may be possible.

However, continued driving is not recommended if the vehicle has:

• Severe shifting

• Transmission slipping

• Limp mode

• No speedometer

• Unexpected gear changes

• Significant loss of transmission performance

If the transmission cannot determine output speed, its control strategy may become unpredictable.

How Is P0722 Repaired?

The repair depends on the confirmed cause.

Possible repairs include:

• Replacing the output speed sensor

• Repairing damaged wiring

• Repairing connector terminals

• Correcting sensor installation

• Repairing power or ground problems

• Repairing internal transmission wiring

• Repairing or replacing a damaged reluctor or tone ring

• Correcting communication problems

• Repairing or replacing the TCM when properly diagnosed

The important point is to identify why the signal is missing before replacing components.

Does P0722 Require Transmission Repair?

Not necessarily.

Many P0722 cases are caused by an electrical problem involving the sensor, connector, or wiring.

If the sensor is located inside the transmission, accessing it may require additional labor, but this still does not automatically mean that the transmission needs rebuilding.

Common Diagnostic Mistakes

Assuming the transmission is mechanically damaged

P0722 is primarily a missing signal code.

Replacing the OSS sensor immediately

The sensor is only one possible cause.

Ignoring the connector

A loose or corroded connector can completely interrupt the signal.

Ignoring wiring

An open circuit can produce exactly the same symptom as a failed sensor.

Testing only while parked

The TCM needs output-shaft rotation to evaluate the OSS signal.

Ignoring the reluctor

A damaged mechanical target can prevent a good sensor from generating a usable signal.

Replacing the TCM without testing

A TCM should not be condemned until the sensor circuit and communication system have been verified.

How Do You Clear P0722?

The underlying problem should be repaired first.

After the repair:

Clear the DTC → Monitor OSS live data → Drive the vehicle → Verify stable output-speed information → Rescan

The TCM should see an appropriate output-speed signal as the vehicle accelerates.

If P0722 returns, the signal path still needs to be investigated.

Final Thoughts on P0722

P0722 – Output Speed Sensor (OSS) Circuit No Signal indicates that the TCM is not receiving the expected output-speed signal from the transmission.

The most important areas to investigate are the output speed sensor, wiring, connector, power supply, ground, internal transmission wiring, and the reluctor or tone ring used by the sensor.

Unlike P0723 – Output Speed Sensor Circuit Intermittent, P0722 indicates that the signal is completely absent or not detectable under conditions where the TCM expects it.

The distinction is important because a completely disconnected sensor, an open circuit, or a failed sensor may cause P0722, while a sensor that occasionally loses its signal is more likely to produce P0723.

P0722 can also lead to secondary transmission problems because the TCM relies on output speed to calculate gear ratios and control shifting. This is why codes such as P0730 and P0731–P0734 may sometimes appear alongside P0722.

A practical diagnostic path is:

Scan all DTCs → Check freeze-frame data → Monitor OSS live data → Compare OSS with vehicle speed → Inspect the sensor → Inspect the connector → Test wiring → Verify power and ground → Inspect the reluctor/tone ring → Check transmission fluid when appropriate → Test the signal waveform → Repair the confirmed fault → Clear the code → Road test and rescan.

Most importantly, P0722 does not automatically mean the transmission needs to be rebuilt. In many cases, the actual cause is found in the speed sensor or its electrical circuit rather than in the transmission's internal mechanical components.