P0720 Code: Honda CR-V (2017-2023) - Causes, Symptoms & Fixes

CODE MEANING AND SEVERITY

• Code: P0720 — Output Speed Sensor Circuit Malfunction
  • What it means: The transmission output speed sensor (often called the OSS or Output Shaft Speed sensor) signal is not being read correctly by the Powertrain Control Module (PCM) or Transmission Control Module (TCM). The OSS provides a speed signal used to regulate transmission shifting and other speed-dependent functions. A fault can be caused by a bad sensor, wiring, poor connections, or occasionally a PCM/TCM issue.
  • Severity for 2017-2023 Honda CR-V: Moderate. It can cause erroneous speed readings, loss of cruise control, irregular or harsh shifting, or even limited operation in some driving conditions. The vehicle will likely drive, but drivability and reliability may be reduced until the fault is repaired. In some cases the ECM/TCM may enter a degraded mode if it cannot trust the speed signal.

Important note based on data you provided: No recalls and no owner complaints were found in the NHTSA data for this make/model/year/issue combination. This means there are no official recall TSBs cited here, and typical repairs focus on sensor/wiring rather than a factory-wide fix.

COMMON CAUSES ON HONDA CR-V

• Faulty Output Speed Sensor (OSS): The sensor itself has degraded accuracy or fails outright.
• Damaged or corroded wiring harness: Wires between the OSS and PCM/TCM can chafe, wear, or get pinched, causing intermittent or missing signal.
• Poor or corroded/incorrect connectors: Bent pins, loose connectors, or moisture can cause intermittent contact.
• Ground or power supply issues in the sensor circuit: Bad ground or improper supply to the sensor circuit can mimic OSS failure.
• Transmission fluid or internal transmission issues: Contamination, low level, or degraded CVT fluid can affect sensor operation or cause electrical noise.
• PCM/TCM software or calibration issue: Rare, but possible if the computer doesn’t correctly interpret the sensor signal after a software change or update.
• External interference or short to another circuit: Wiring routing near high-current circuits or heat sources can cause faults.

SYMPTOMS

• Speedometer not reading correctly or fluctuating; sometimes stuck at zero.
• Cruise control inoperative or inconsistent operation.
• Transmission shifts erratically, harshly, or unpredictably; potential for slipping or delayed shifts.
• Vehicle may enter a degraded/limp-like mode or present intermittent drivability issues.
• Check Engine Light (CEL) illumination with DTC P0720 stored.
• Other speed-dependent functions (e.g., ABS-related logic relying on speed) may behave irregularly if the OSS signal is widely disturbed.

Note: Symptoms can be intermittent; some drivers may notice only a non-functioning cruise control or a hiccup in shifting rather than a full-speed signal loss.

DIAGNOSTIC STEPS

A structured approach to diagnose P0720 on a 2017-2023 Honda CR-V:

• Step A: Confirm and document

  • Use a capable OBD-II scanner to confirm P0720 and note any freeze-frame data and related codes (look for P0721, P0722, P0723 or others if present).
  • Check for symptoms in real time with live data: vehicle speed, OSS signal (if your tool can display it), and transmission status.

• Step B: Inspect the OSS sensor and harness

  • Locate the OSS on the transmission output shaft (exact location varies by model/engine; refer to service manual or a repair guide for your year).
  • Visually inspect the sensor, its connector, and the wiring harness for obvious damage, corrosion, dirt, or moisture.
  • Inspect for loose, bent, or corroded pins in the connector; reseat and clean connectors if needed.
  • Look for wiring damage along the harness route (chafing, abrasion, heat exposure, or intrusion by moving components).

• Step C: Test the sensor circuit (voltage, continuity, resistance)

  • With ignition ON (engine OFF or as specified by manual), verify the sensor connector is receiving the expected reference signals (some OSS sensors are two-wire and require a scan tool for the signal rather than a simple voltage check).
  • Check continuity between the OSS sensor and the PCM/TCM pin on the control module harness for both signal and ground wires; inspect for opens or shorts to ground/battery.
  • Measure resistance across the OSS sensor terminals if applicable. Compare against the service manual specification for the OSS resistance (some OSS sensors are frequency-output devices rather than a simple resistive sensor).
  • Wiggle the connector and wiring while monitoring the OSS signal with a live data tool to look for intermittent contact.

• Step D: Test with live data (preferred)

  • Use a scan tool capable of live data to watch the OSS output while pulling the vehicle slowly by hand or test-driving safely. The OSS should produce a steady frequency correlated to speed; the signal should not randomly disappear or jump erratically.
  • If the OSS signal is absent, erratic, or out of range while other speed signals (like the vehicle speed readout) are normal, suspect OSS or its wiring.

• Step E: Rule out related components

  • If wiring and sensor test OK, consider PCM/TCM software/calibration update or reflash (check for service bulletins or updates via dealer if applicable, though your data indicates no recalls here).
  • If available, temporarily swapping to a known-good OSS sensor can help confirm the fault (note this requires appropriate tools and caution).

• Step F: Road test to confirm

  • After repairs or sensor replacement, perform a controlled road test to ensure speedometer accuracy, reliable cruise control operation, and proper shifting behavior across various speeds and loads.

Data limitation note: The provided data states no recalls and no owner complaints in NHTSA for this combination, so diagnostic steps here are based on standard automotive diagnostic practices and known patterns for P0720 in modern Hondas, not on a specific NHTSA-issued Honda CR-V fix.

RELATED CODES

• P0721: Output Speed Sensor Range/Performance — indicates the OSS signal is out of expected range or timing is off.
• P0722: Output Speed Sensor Circuit No Signal — indicates a lack of signal from the OSS circuit (open circuit, disconnected, or severely damaged wiring).
• P0723: Output Speed Sensor Circuit Low Input (or similar variant) — indicates a low/weak OSS signal.
  Note: These related codes are commonly encountered with OSS/wiring issues and may appear alongside P0720 depending on exact fault data and scan tool interpretation. The diagnostic approach often overlaps with P0720 when investigating speed-sensor-related faults.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices are estimates and vary by region, shop, and availability. All prices are approximate ranges in USD.

• Quick/DIY checks and basic parts

  • Diagnostic fee (if you go to a shop): typically $80–$120 (some shops waive it if you proceed with repairs).
  • OSS sensor replacement part: $40–$120
  • Basic connectors or small harness repair parts: $10–$40
  • Estimated DIY time: 0.5–2 hours

• OSS sensor replacement

  • Parts: $40–$120
  • Labor: 0.5–1.5 hours
  • Typical total: $100–$300 (depending on labor rate)

• Wiring/connector repair or harness replacement

  • Parts: $10–$60 (connectors, heat shrink, weather pack, etc.)
  • Labor: 1–2 hours
  • Typical total: $150–$350

• Transmission control module (TCM) or PCM software update (reflash) or replacement

  • Software update/reflash: $100–$250 (plus diagnostic time)
  • If PCM/TCM replacement is required: $400–$1,500 for parts plus $100–$600 for labor (and programming fees)
  • Note: PCM/TCM replacement is less common for a simple OSS fault; most P0720 fixes are sensor/wiring related.

• Transmission service, flush, or related CVT maintenance

  • CVT fluid service/flush: $150–$250 (not a guaranteed fix for P0720, but may be recommended if fluid condition is contributing to electrical noise or sensor operation)

• Transmission removal/rebuild or CVT replacement (if internal hardware or transmission fault is diagnosed)

  • Very variable: typically $2,000–$5,000 or more for a full rebuild or CVT replacement, excluding additional labor

• Diagnostic charge (if you don’t proceed with repair)

  • $80–$150

DIY VS PROFESSIONAL

• DIY-friendly scenarios (typical for a shop visit to replace OSS or inspect wiring):

  • When the OSS sensor and its connector are readily accessible without major disassembly.
  • When you have basic hand tools, a DVOM, and a multimeter or oscilloscope and can safely lift the vehicle.
  • You can replace the OSS sensor and reseat/clean connectors, then retest with live data.

• DIY caveats:

  • Some OSS sensors are mounted in hard-to-reach places on the transmission; replacement may require jack stands, proper support, and attention to CVT fluid handling.
  • Testing the actual OSS signal reliably often requires a modern scan tool capable of live data or an oscilloscope; a basic code reader may not reveal the sensor behavior.

• Professional route:

  • Recommended if you don’t have the right tools or if wiring and connector repair requires precise diagnostics (continuity tests, harness replacement, or PCM/TCM reprogramming).
  • A pro can perform precise voltage/current tests, swap sensors, and confirm the fault with road testing and proper data logging, reducing the risk of misdiagnosis.

PREVENTION

• Regular CVT maintenance
  • Use Honda-certified CVT fluid and follow the manufacturer’s maintenance schedule. Contaminated or degraded CVT fluid can worsen electrical noise and sensor accuracy.
  • Check fluid level and condition at recommended intervals; replace when required.
• Electrical harness care
  • Periodically inspect the OSS wiring harness for wear, chafing, or damage, especially along routing paths near hot components or moving parts.
  • Keep connectors clean and dry; use dielectric grease on connectors to resist moisture and corrosion.
• Avoid physical damage to the transmission area
  • Protect cables and sensors from road debris, steering linkages, and undercarriage impacts.
• Smooth operation
  • Avoid aggressive hard launches or high-torque starts that stress the transmission wiring harness and sensor interfaces.
• Software updates
  • If you encounter related issues, check with a Honda dealer for any available PCM/TCM software updates or service bulletins that may affect speed sensor interpretation.

Data limitations and transparency

• The data you supplied shows:
  • No owner complaints in NHTSA for this make/model/year/issue combination.
  • No recalls found in NHTSA database for this make/model.
• Consequently, the guide relies on general P0720 diagnostic practices and common Honda CR-V transmission sensor behavior, not on specific Honda-released recalls or TSBs for this DTC.
• If you have a dealership or shop manual for your exact VIN, consult it for the precise OSS location, connector pinout, and the recommended test values for your specific CVT version and engine (the CR-V used across 2017–2023 can have differing sensors depending on engine and transmission options).