P0654
Engine RPM Output Circuit/Open
Control module output
Generic OBD-II
Medium
What it means
P0654 means the ECM detected an open in the engine RPM output circuit — the signal the ECM sends out to the tachometer and other modules that need engine speed. This is an output, not the crankshaft position sensor, so the engine keeps running and starting normally; the main effect is a wrong or dead tachometer and any module that relies on that signal.
Medium
Can I keep driving? The engine runs normally — this is an output signal, not the crank sensor. The tachometer or modules that read engine speed may be wrong, so it's generally safe to drive.
Common symptoms
What you'll notice
- Inaccurate or dead tachometer
- Check-engine light on
- Other modules that rely on the engine-speed signal may misbehave
- Engine itself runs and starts normally
Common causes
Most likely first
- Open or short in the RPM output wiring between the ECM and the cluster/moduleLikely
- Corroded or loose connector in the output circuitCommon
- Faulty instrument cluster or receiving moduleCommon
- Less commonly, a faulty ECM output driverLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to confirm it's the RPM output circuit.
- Inspect the wiring from the ECM to the tachometer/receiving module for opens or shorts.
- Check the connectors at the ECM and the cluster/module.
- Test the ECM's output signal; if present, suspect the wiring or receiving module.
- Repair the wiring or replace the faulty module, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P0654?+
Yes, generally. This is an output signal to the tachometer and other modules, not the crankshaft sensor, so the engine runs and starts normally.
Can I just clear P0654?+
It will return until the open or short in the output circuit is repaired. Clearing won't restore a correct tachometer reading.
Related codes
Often seen with P0654
Read & clear P0654 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX