Engine Speed Input Circuit No Signal
No signal from the engine speed sensor detected by the PCM.
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 engine speed sensor, which tracks how fast the engine is spinning, isn’t sending any information to the computer, often leading to issues with engine performance and preventing the vehicle from starting.
What the computer is actually seeing
The PCM expects a continuous signal (usually a square wave) from the engine speed sensor corresponding to engine RPM. When the signal is absent, the PCM registers a fault.
What a healthy reading looks like
A functioning engine speed sensor sends a signal voltage pulse between 0.5V to 5V based on engine RPM, at a frequency proportional to engine 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 engine speed sensor connector for damage, corrosion, or looseness. Repair as necessary. Decision: Is the connector good? If yes, go to Step 2; if no, repair it and retest.
Common causes
- Disconnected or damaged engine speed sensor connector
- Faulty engine speed sensor
- Wiring issues between the sensor and the PCM
- Faulty PCM
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
No, driving with this code may result in a no-start condition or cause the vehicle to go into limp mode.
Will this issue come back after fixing?
If the root cause is addressed properly, it shouldn't return.
Why does this code pair with speed sensor issues?
Because the PCM relies on engine speed information for optimal engine performance and many systems depend on accurate speed readings.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
Start guided diagnostic →