Generic OBD-II / Powertrain

P0386 - The Crankshaft Position Sensor B Signal Is Out of Range or Not Believable

P0386 is a generic OBD-II code for a crankshaft position sensor B range or performance problem.

This is a generic OBD-II guide that can apply across many makes. Exact test flow, sensor locations, and repeat failure patterns can still vary by manufacturer and engine family.

Severity

Medium

Keep driving?

Usually short trips only

Most likely cause

A weak sensor, wiring fault, or tone wheel issue is usually the first place to look.

DIY friendly?

Basics first

First checks take 10 minutes for basic checks. No special tools are usually needed for the first checks.

Can you keep driving?

Can you keep driving?

Stop driving if any of these apply

  • !The vehicle suddenly runs much worse, loses power sharply, or the check-engine light starts flashing.
  • !There is a strong smell, smoke, overheating, or any symptom that suggests a real-time safety problem rather than a stored code alone.
If the light is steady and the vehicle still drives normally: Often yes for a short time, but it should not be ignored if drivability changes are obvious.

What to check first

Step-by-step checks

  1. 1

    Free - no tools

    Check whether the engine has a hard-start, stall, or rough-run symptom with the code

  2. 2

    Free - no tools

    Inspect the sensor connector and harness for oil, heat, or abrasion damage

  3. 3

    Basic tool needed

    Look for related crankshaft, camshaft, or misfire codes that may help with diagnosis

  4. 4

    Basic tool needed

    If scan data is available, compare crank signal stability with engine RPM behavior

  5. 5

    Basic tool needed

    Notice whether the code appeared after timing work or sensor replacement

If the code returns

  • -If the signal is present but not believable, the sensor or tone wheel becomes more likely.
  • -If the signal looks okay but the engine still has timing problems, inspect the mechanical side.
  • -If the code returns after connector repair, recheck sensor fit and wiring routing.

Background

What this code means

P0386 is a generic OBD-II code for a crankshaft position sensor B range or performance problem.

The engine controller is seeing a crank signal, but it does not look believable for the operating condition. That can come from the sensor, the wiring, or the reference wheel it reads.

Diagnosis

Common causes

Most common

Weak crankshaft position sensor B

The sensor may still work but not produce a believable signal.

Common

Wiring or connector damage

Heat, oil, or corrosion can distort the signal.

Common

Damaged tone wheel

The reference pattern may be worn or bent.

Possible

Sensor gap or mounting issue

A poor gap or loose mount can make the signal look out of range.

Avoid these mistakes

What not to do

  • xDo not replace the ECU first if the sensor or tone wheel is visibly damaged.
  • xDo not ignore starting or stalling symptoms that line up with the crank signal fault.

Parts

Parts that may need replacing

PartTypical costNotes
Crankshaft position sensor B$40-$180Worth checking when the crank signal is implausible or unstable.
Connector or wiring repair$50-$250Useful when the circuit is contaminated or intermittent.
Tone wheel or reluctor repair$200-$900Relevant when the mechanical reference pattern is damaged.

See also

Related OBD codes

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0386 was seeded from dtcdb and then expanded around crankshaft position sensor B range/performance faults, with emphasis on sensor, wiring, and tone-wheel checks.

This guide is written as a generic multi-make reference, so bulletin history, sensor locations, and repair order can still change by manufacturer and engine family.

This is generic OBD-II guidance and should not override vehicle-specific service information. Exact diagnosis and repair steps vary by make, engine family, and model year.

Last reviewed: 2026-04-10

Reference: Open reference

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