OBD-II Code
P0386
Severity
Not yet reviewed
Nobody on our side has assessed this code yet, so we are not going to guess at how serious it is.
Can you drive it
We cannot say
Treat it as unknown until a shop reads it with live data. If the check-engine light is FLASHING, stop driving as soon as it is safe to — that means an active misfire, whatever the code.
Indicative cost (USD)
$150–$600
From this code's diagnostic notes. Varies by vehicle, diagnosis, parts, and local labor. This is not a repair quote.
P0386 means the secondary crankshaft position sensor (CKP-B, also called 'Crank Sensor B' or on some platforms a cam-driven angle reference) is reporting a signal that's electrically present but mechanically implausible — pulse spacing inconsistent with engine speed, missing-tooth pattern mis-aligned with what CKP-A reports, or amplitude variation across one revolution that exceeds the controller's range/performance window.
How a shop works this
Work from evidence to part, not the other way round. A code names a circuit or a symptom; it does not name the part that failed.
Note every code that is set, not just this one.
Codes that appear together usually narrow the cause faster than any one of them read alone.
Read the freeze frame — the conditions the fault was recorded under.
Cold or warm, idle or load, road speed and engine speed. A fault that only appears cold is a different fault from one that only appears under load, even with the same code on the scanner.
Confirm the fault is current rather than history.
Clear the code and see whether it returns under those same conditions. A code that does not come back may have been logged during a repair, a flat battery, or a bad connection that has since been disturbed.
Then follow the diagnostic notes further down this page, in the order they are written.
They are written in the order a shop works this code, cheapest checks first. Where they name a component, inspect its wiring and connector before replacing it.
If the code comes back after a repair, the underlying fault is still there. That is the point to bring in a scanner with live data and freeze-frame, or a shop that has one.
Common symptoms
- Check engine light
Read the full diagnostic procedureP0386 means the secondary crankshaft position sensor (CKP-B, also called 'Crank Sensor B' or on some platforms a cam-driven angle reference) is repor…
P0386 means the secondary crankshaft position sensor (CKP-B, also called 'Crank Sensor B' or on some platforms a cam-driven angle reference) is reporting a signal that's electrically present but mechanically implausible — pulse spacing inconsistent with engine speed, missing-tooth pattern mis-aligned with what CKP-A reports, or amplitude variation across one revolution that exceeds the controller's range/performance window.
Cheapest-first ladder
- scan-tool both CKP signals (RPM-A and RPM-B) simultaneously at idle and verify they track within +/- 1 rpm — divergence at steady idle is a correlation fault.
- Two-channel scope the sensors during a cold cranking event — a Hall-effect CKP-B produces a clean 0-5V square wave at roughly 300 pulses/sec at 200 rpm cranking on a 58-tooth wheel; a VR sensor produces 0.5-1.5 V AC at cranking, rising to 5-15 V peak-to-peak above 2,500 rpm. Range/performance faults show up as occasional missed edges, doubled pulses where the reluctor has a chip, or amplitude that fluctuates more than 30% within a single revolution.
- Pull the sensor and inspect the tip for metallic debris (especially on VR sensors), and check the air-gap shim/spacer is the correct OEM thickness (typically 0.5-1.5 mm; an undersized shim lets the tip strike the reluctor on heat-expanded cycles).
- Inspect the reluctor wheel for chipped or bent teeth — a single bent tooth shows as one bad pulse per revolution and is the most common mechanical cause. Expensive-misdiagnosis caveat: before replacing the sensor for P0386, verify the air-gap and reluctor — a reluctor that has shifted axially because of a worn thrust bearing or stretched timing chain reads as 'range/performance' on the scope; a new sensor lasts about 200 miles before the same code returns.
Vehicle-specific patterns2002-2014 Subaru EJ-series (EJ20/EJ25, including turbo WRX/STI and naturally-aspirated Outback/Forester/Legacy) is the most common platform throwing…
- 2002-2014Subaru EJ-series (EJ20/EJ25, including turbo WRX/STI and naturally-aspirated Outback/Forester/Legacy) is the most common platform throwing P0386 — Subaru runs a cam-driven angle reference on the opposite head from the primary CKP, and the secondary sensor's mounting boss cracks at the head casting, allowing the sensor to walk in its bore and lose air-gap consistency.
- 2004-2013Subaru turbo applications (WRX/STI/Forester XT/Legacy GT) see P0386 acutely because turbo heat soak warps the bracket.
- 2004-2011Mazda RX-8 uses a secondary rotor-position back-up sensor; P0386 typically points to a contaminated tip from oil-injection blow-by.
- 2003-2010Ford 6.0L Powerstroke and 2008-2010 6.4L throw P0386 alongside cam-correlation codes when the front timing cover bushing wears and the reluctor wobbles.
Estimated repair$150 to $600.
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