Output Speed Sensor Circuit Malfunction
Signal from the output speed sensor is not making it to the engine control unit.
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What it means (plain English)
The output speed sensor tracks how fast the transmission output shaft is spinning. If it fails, the computer can't adjust shift points properly, which can affect how the vehicle drives.
What the computer is actually seeing
The engine control unit (ECU) expects a voltage signal from the output speed sensor that reflects the shaft speed. Typically, it sees voltage spikes that indicate the rotations per minute (RPM) of the output shaft, usually from 0.5V to 5V, depending on the design.
What a healthy reading looks like
The expected output from the OBD-II output speed sensor should vary between 0.5V at 0 RPM to approximately 5V at maximum RPM, with a frequency related to shaft speed.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 11. Check the wiring and connectors for the output speed sensor. Look for any frays or corrosion. If damaged, repair as needed. Decision: Is the wiring intact? (Yes: go to step 2; No: repair wiring)
- 22. Check the output speed sensor itself with a multimeter. Measure the resistance across the sensor terminals, should be between 200-800 ohms. Decision: Is the resistance within range? (Yes: go to step 3; No: replace the sensor)
- 33. With the vehicle running, monitor the sensor signal using a scan tool. You should see a voltage response that fluctuates as the vehicle is driven. Decision: Is the voltage output responding correctly? (Yes: check the ECU; No: replace the speed sensor)
- 44. Clear the code and take the car for a test drive to see if it returns. If it does, and diagnostics point to the ECU, consider reprogramming or replacing it.
Common causes
- Wiring harness damage
- Faulty output speed sensor
- Bad connectors or corrosion
- Transmission fluid issues
- ECU malfunction
Typical repair cost
$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It's not recommended to drive for long with this code, as it can lead to erratic shifting and transmission damage.
Will the code come back after clearing?
If the underlying issue is not fixed, the code is likely to return soon after clearing.
Why does this code show up with other transmission codes?
The output speed sensor is critical for shifts; issues here can impact overall transmission function, leading to multiple codes.
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