Vehicle Speed Sensor Circuit A
The vehicle speed sensor circuit A has a fault.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The vehicle speed sensor is either disconnected or sending irregular signals, which the computer uses to determine how fast you're going.
What the computer is actually seeing
The engine control module (ECM) expects a square wave signal from the vehicle speed sensor with a frequency that represents wheel speed. If it doesn't receive this signal, or receives a signal outside its expected range, it flags an error.
What a healthy reading looks like
Expected signal frequency should be between 0Hz (stationary) and up to 10,000Hz (high speed); Voltage should vary between 0.5V and 12V depending on 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. Inspect wiring and connectors for damage or corrosion. Check for loose connections between the vehicle speed sensor and the ECM.
- 22. Measure the voltage at the speed sensor connector while the vehicle is running; you should see a fluctuating voltage. If there's no voltage, repair the wiring first.
- 33. If the wiring is good, disconnect the speed sensor and check its resistance; it should typically be between 800-1200 ohms. Replace the sensor if the resistance is out of range.
- 44. Clear the code and test drive the vehicle to see if the code returns. If it does, further diagnose the ECM or related modules.
Common causes
- Damaged or corroded wiring
- Faulty vehicle speed sensor
- Bad connector at the sensor or ECM
- Faulty ECM or other control modules
Typical repair cost
$$$
Related codes
Frequently asked questions
Can I drive my vehicle with this code?
Yes, but you may experience erratic speedometer readings or transmission shifting issues; address it soon.
Will the code come back after clearing it?
It may come back if the underlying issue isn’t fixed; monitor your vehicle’s symptoms after repairs.
Why does this code pair with other codes?
Speed sensor issues can affect multiple systems, leading to codes for other related sensors or components.
Working a real vehicle right now?
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