OBD-II Code · Powertrain
P0720
Output Speed Sensor Circuit
Severity
high
Left alone, this one tends to take other parts with it.
Can you drive it
Not for long
Driving on this one risks further damage. Get it to a shop rather than carrying on with it.
Indicative cost (USD)
$150–$500
Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
Trans output-shaft speed sensor circuit fault.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then work the likely-causes list in the order shown.
That order is what a shop checks first for this code — wiring and connections before the component they run to, because a connector costs nothing to inspect and is a common answer.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Speedo erratic
- Harsh shifts
- Trans limp
Likely causes
- Failed sensorMost common
- Damaged tone ring
- Wiring
Read the full diagnostic procedureP0720 is the output-side mirror of P0715: the TCM has lost or can't validate the signal from the Output Speed Sensor (OSS), which reads the final sha…
P0720 is the output-side mirror of P0715
the TCM has lost or can't validate the signal from the Output Speed Sensor (OSS), which reads the final shaft speed feeding the driveshaft. The TCM uses OSS for vehicle speed (it's often the source the speedometer reads from on modern vehicles), for gear-ratio math (input RPM ÷ output RPM = actual ratio, compared against commanded ratio to detect slip), and for downshift scheduling. Lose it and you get a dead or erratic speedometer, harsh shifts, no TCC lockup, and often a limp-home default to a single gear. Fluid level and condition come first as always — but P0720 has a higher-than-usual rate of external causes because the OSS sits at the rear of the case, exposed to road debris and harness chafing where the trans meets the transfer case or driveshaft. Scan live data with the vehicle on a lift: in DRIVE, output RPM should rise smoothly with road speed (roughly 1,000 RPM per 25 mph on most trucks, but the exact ratio depends on final drive). A reading of 0 with the wheels turning is a dead sensor or open circuit; an erratic reading that jumps to redline values is usually a chafed harness shorting intermittently.
Vehicle-specific patterns2003-2010 Ford Explorer/Mountaineer/Ranger with the 5R55W/S throws P0720 from a failed OSS at the rear extension housing — the harness routing rubs t…
- 2003-2010Ford Explorer/Mountaineer/Ranger with the 5R55W/S throws P0720 from a failed OSS at the rear extension housing — the harness routing rubs the driveshaft slip yoke at suspension travel, $35 sensor + harness repair.
- 2007-2013GM Silverado/Sierra 4WD trucks with the 6L80 throw P0720 when the transfer-case-to-trans wiring loom corrodes at the disconnect plug; cleaning and dielectric grease fixes it more often than replacing the sensor.
- 2005-2010Honda Odyssey/Pilot with the 5AT (BGRA/BYBA) commonly throws P0720 from a known countershaft speed sensor failure — there's a Honda TSB and these were warranty-replaced under powertrain coverage on some VINs.
- 2008-2014Nissan Altima/Murano with the JF016E CVT throws P0720 alongside a half-dozen other ratio codes when the CVT's pulley pressure sensors degrade — at that point you're looking at a CVT replacement, not a speed sensor.
Estimated repair$120 (sensor + harness) to $4,500+ (CVT replacement on the Jatco).
Look up another code
P0720 — frequently asked
What does a P0720 code mean?
Trans output-shaft speed sensor circuit fault.
What causes a P0720 code?
Common causes: Failed sensor; Damaged tone ring; Wiring.
What are the symptoms of a P0720 code?
Typical symptoms: Speedo erratic; Harsh shifts; Trans limp.
Is it safe to drive with a P0720 code?
Not for long. Driving on this one risks further damage. Get it to a shop rather than carrying on with it. Estimated repair: $150-$500.
How do I diagnose a P0720 code?
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed. 1. Note every code that is set, not just this one. 2. Read the freeze frame — the conditions the fault was recorded under. 3. Confirm the fault is current rather than history. 4. Then work the likely-causes list in the order shown.
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