P2618
Crankshaft Position Signal Output Circuit Low
Ignition / crank position
Generic OBD-II
Medium
What it means
P2618 means the engine computer detected low voltage (a short or open) in the circuit that outputs the crankshaft-position/engine-speed signal to other modules — for example the tachometer or transmission controller. This is the signal-output circuit, not the crank sensor itself, so the engine usually still runs; expect a check-engine light and possibly an erratic tach or shifting.
Medium
Can I keep driving? Usually still drives — this is the engine-speed signal the PCM sends to other modules, so expect an erratic tach or shifting rather than a stall; get it checked.
Common symptoms
What you'll notice
- Check-engine light on
- Tachometer reading erratically or dropping to zero
- Harsh or erratic shifting if the transmission uses the signal
- Occasional hesitation if a downstream system reacts to the bad signal
Common causes
Most likely first
- Short to ground or open in the crank-signal output wiringLikely
- Poor connection at a receiving module or the PCM output pinCommon
- Corroded or damaged connectorCommon
- Faulty PCM output driverLess often
- Failing crankshaft position sensor feeding the PCM (less common)Less often
How to diagnose & fix
Work through it in order
- Read freeze-frame and check for accompanying crank-sensor codes (P0335/P0336).
- Inspect the output-circuit wiring and connectors between the PCM and the modules it feeds.
- Check the signal wire for a short to ground or an open.
- Verify the crankshaft position sensor input is clean before blaming the output circuit.
- If wiring checks out, suspect the PCM driver; recheck after repair.
FAQ
Quick answers
Is it safe to drive with P2618?+
Usually yes for a short trip — this is the signal-output circuit, not the crank sensor itself, so the engine keeps running. But an underlying crank-sensor fault could cause a stall, so get it diagnosed soon.
Can I just clear P2618?+
It will return until the output-circuit wiring or driver is repaired. Clearing it also wipes the freeze-frame data that helps pinpoint the fault.
Related codes
Often seen with P2618
Read & clear P2618 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