What are the symptoms of a bad speed sensor on a Honda?

A faulty speed sensor can cause a range of issues, with the most noticeable being problems with the speedometer, the cruise control, and the way the car shifts. If you’re seeing multiple warning indicators or unusual driving behavior, a bad speed sensor is a common culprit to check first.

What the Vehicle Speed Sensor Does

The vehicle speed sensor (VSS) measures how fast the car is moving and relays that information to several onboard systems. It helps the speedometer read correctly and informs the engine control unit, transmission control module, and sometimes the ABS system about vehicle speed. In many Honda models, the VSS is located on or near the transmission output shaft. When the sensor fails or its wiring becomes compromised, data can become unreliable, leading to a cascade of symptoms across different systems.

Common Symptoms

Below are the most commonly reported signs you might notice in everyday driving when the VSS starts to fail. The list focuses on practical, observable effects you can verify on the road.

• Speedometer reads erratically, fluctuates, or stays at 0 mph/kph.


• Cruise control will not engage, drops out, or behaves inconsistently.


• Transmission shifts at wrong times, feels harsh, or exhibits delay in upshifts or downshifts.


• Check Engine Light or transmission/ABS warning lights illuminate; diagnostic codes related to speed sensing may be stored.


• ABS or traction control warning lights may appear if the sensor data is used by those systems.

These symptoms can vary by Honda model and year, but they commonly point to a fault in the speed sensor or its wiring. If you notice any of these signs, it’s wise to diagnose the sensor and related circuits to prevent further issues.

Additional Signs and Safety Considerations

Additional indicators that may accompany a bad VSS—and affect driving safety—include the following. These notes help explain how the sensor interacts with other systems.

• Vehicle may show inconsistent readings during acceleration or cruising, even if the rest of the gauges seem normal.


• Diagnostic Trouble Codes (DTCs) such as P0500 (Vehicle Speed Sensor Malfunction) or P0501 (Vehicle Speed Sensor Range/Performance) may appear on an OBD-II scan. Model-year variations exist.


• Wiring or connector issues at the sensor, such as corrosion, loose pins, or damaged insulation, can mimic or amplify sensor failure.

Because the VSS feeds multiple control systems, a true fault can lead to a combination of symptoms rather than a single issue. A professional scan helps distinguish a bad sensor from related wiring or module problems.

Diagnosis and Fixes

If you suspect a bad VSS on a Honda, these steps outline the usual approach technicians take to confirm the fault and restore proper operation.

1. Use an OBD-II scanner to pull speed-related trouble codes and compare the reported speed to the dashboard reading.


2. Inspect the VSS wiring harness and connector for signs of wear, corrosion, or loose pins; repair or replace as needed.


3. Test the sensor’s electrical values (and resistance) according to the service manual, or swap in a known-good sensor to verify the fault.


4. Check related systems (transmission control module, ABS/ESP data flow, and instrument cluster) for data integrity and confirm no cascading faults exist.


5. Replace the VSS if testing confirms failure; clear codes and re-test to ensure normal speed readings and proper shifting.

Note: Replacement procedures and the sensor’s exact location vary by Honda model and year. If you’re not experienced with automotive electrical diagnostics, a certified mechanic or Honda dealership can perform the diagnosis and replacement safely and accurately.

Summary

A failing speed sensor in a Honda typically presents as a faulty or erratic speedometer, loss or irregularity of cruise control, and abnormal transmission shifting, often accompanied by warning lights. Diagnosis relies on scanning for codes, inspecting wiring, and testing the sensor, with replacement generally restoring accurate speed readings and proper drivetrain behavior. Prompt attention helps prevent further transmission or braking-related issues.

Which speed sensor controls the speedometer?

The Vehicle Speed Sensor (VSS) controls the speedometer by sending the vehicle's speed information to the car's computer. This sensor is typically mounted on the transmission and detects the rotation of a gear or a reluctor ring, which the computer uses to calculate and display the vehicle's speed on the speedometer. 
This video explains the difference between vehicle speed sensors and transmission speed sensors: 58sAuto V Fix YouTube · Jul 19, 2022
How it works

• Sensing rotation: The VSS is usually mounted near the transmission's output shaft, where a toothed ring or gear rotates with it.
• Generating a signal: As the gear spins, its teeth pass by the sensor, which has a magnetic tip. This creates a series of electrical pulses or a signal.
• Calculating speed: The car's computer (ECU or PCM) counts these pulses over a period of time. The more pulses it receives, the faster the vehicle is moving.
• Displaying speed: The computer uses this calculated speed to send the correct reading to the speedometer. 

Other systems that use the VSS
The VSS provides crucial data for several other vehicle systems: 

• Automatic transmission: The computer uses speed data to determine when to shift gears. 
• Cruise control: The system needs the VSS data to maintain a set speed. 
• Anti-lock brakes (ABS) and traction control: On many modern vehicles, the VSS signal is also used by these safety systems. 

You can watch this video to learn about the symptoms of a bad speed sensor: 56sThe AbJ GarageYouTube · Aug 28, 2024

What happens when the speed sensor goes bad?

When a speed sensor goes bad, the vehicle's computer receives incorrect information about its speed, leading to symptoms like a malfunctioning speedometer, erratic or harsh gear shifts, the check engine light turning on, and cruise control failure. This can also cause issues with other systems that rely on speed data, such as the ABS or anti-lock braking system. 
Common symptoms of a bad speed sensor 

• Erratic or broken speedometer: The most obvious sign is a speedometer that jumps around, doesn't register any speed, or displays inaccurate information. 
• Check Engine Light: The "check engine" light may come on at random times, or more frequently when accelerating, indicating a potential issue with the speed sensor. 
• Poor transmission performance: Gears may shift harshly, late, or not at all. The vehicle may feel sluggish or hesitate during acceleration. 
• Cruise control failure: The cruise control may fail to engage, disengage unexpectedly, or not maintain a set speed. 
• ABS warning light: The ABS warning light may stay on continuously, as this system also relies on speed sensor data to function correctly. 
• Reduced fuel efficiency: Some vehicles may experience reduced fuel economy because the engine's control unit is not optimizing performance without accurate speed data. 
• Difficult braking: In some cases, you might experience harder braking when coasting. 

Will a bad speed sensor throw a code?

Yes, a bad speed sensor will typically throw a diagnostic code, often illuminating the "check engine" light or an ABS warning light. The specific code will depend on the type of speed sensor that has failed (e.g., a wheel speed sensor, a transmission speed sensor), and it may also cause other problems like shifting issues or a non-functional speedometer. 
This video explains the symptoms of a bad transmission speed sensor: 1mMaxTheCarGuyYouTube · Nov 5, 2023
Common symptoms and codes

• Check Engine or ABS Light: A faulty speed sensor will trigger a warning light on the dashboard, such as the check engine light or the ABS (Anti-lock Braking System) light. 
• Specific Codes:
  • P0500: This is a common "P-code" for a general vehicle speed sensor (VSS) malfunction. 
  • P0720: This code indicates a problem with the output speed sensor (OSS) in the transmission. 
  • C-codes: These are typically associated with the ABS system. For example, C0035 indicates a problem with the front left wheel speed sensor. 
• Other symptoms: A bad speed sensor can also cause: 
  • Erratic or delayed gear shifting. 
  • A malfunctioning or erratic speedometer and odometer. 
  • Cruise control to be disabled or not work properly. 
  • Reduced fuel economy. 
  • Stability and traction control systems to shut down. 

You can watch this video to see how to test a wheel speed sensor: 1mValley Mobile AutomotiveYouTube · Nov 13, 2021
What to do if you have a code

• Use an OBD-II scanner to read the specific diagnostic trouble code. 
• The code will help pinpoint which sensor is having an issue. 
• Inspect the sensor and its wiring for any physical damage or loose connections. 
• If the problem persists, consult a mechanic to properly diagnose and replace the faulty sensor. 

How much does it cost to replace a transmission speed sensor?

The total cost to replace a transmission speed sensor typically ranges from $150 to $350, but can be higher or lower depending on the vehicle. The cost is a combination of parts, which usually run $25 to $100, and labor, which can take one to two hours. Some vehicles with sensors that are difficult to access or that have been seized may have higher repair costs. 
This video explains the cost to replace a transmission speed sensor: 53sTalkingTechTrendsYouTube · May 5, 2025
Cost breakdown

• Parts: Expect to pay between $25$ 25$25 and $100$ 100$100 for the sensor itself, depending on your vehicle's make and model. 
• Labor: The repair generally takes one to two hours. At an average hourly rate, this can cost between $125$ 125$125 and $250$ 250$250. 
• Total cost:
  • For most common vehicles, the total cost is around $150$ 150$150 to $200$ 200$200. 
  • A more typical range is $175$ 175$175 to $350$ 350$350. 
  • Costs can be significantly higher if the sensor is in a hard-to-reach location or if additional parts like a wiring harness are needed. 

Factors that can affect the price

• Vehicle make and model: The price of the part and the complexity of the job vary significantly by vehicle. 
• Accessibility: If the sensor is in a hard-to-reach area and requires more disassembly, labor costs will be higher. 
• Seized sensors: If a sensor is old and stuck, it may need to be drilled out, which increases the labor time and cost. 
• Additional parts: In some cases, the wiring harness may need to be replaced, adding to the total cost.