P0386 Crankshaft position sensor B signal out of range or not performing as expected

Crankshaft position sensor B circuit range/performance

P0386 in short

P0386 means the engine computer reports a range or performance problem with crankshaft position sensor B. The sensor, its wiring or its connector is the usual cause. Depending on the vehicle, the engine may start hard, run rough, stall or not start, so get it checked soon and avoid relying on the car until it is.

The crankshaft position sensor tells the engine computer how fast the engine turns and where the pistons are, so it can time fuel and spark. P0386 is set when the signal from crankshaft position sensor B is outside the range or pattern it expects.

TroubleCodes.net and the Delaware DMV list agree on the generic title: Crankshaft Position Sensor B Circuit Range/Performance. The code points at the sensor B circuit but does not say which part failed.

Sensor, wiring and connector are the usual suspects, and the computer is checked last. Which engine is affected, and what 'B' refers to, depends on the maker, so use the vehicle's own service information.

Most likely causes

These are general causes for this code across vehicles. None is specific to one make or model.

  1. Crankshaft or camshaft position sensor that is faulty

    Common general cause
    Why it ranks here
    TroubleCodes.net lists a defective crankshaft or camshaft sensor first.
    What would change this
    Rises if the sensor tests open, shorted or gives no signal while cranking. Falls if the sensor tests normal.
    How to test the crankshaft position sensor

  2. Damaged wiring or connector between the sensor and the computer

    Common general cause
    Why it ranks here
    TroubleCodes.net lists harness damage, corrosion and loose or contaminated connectors for this code.
    What would change this
    Rises if the harness is chafed, corroded or wiggling it changes the signal. Falls if the circuit tests clean end to end.

  3. The engine computer or its programming

    Possible — needs testing
    Why it ranks here
    TroubleCodes.net lists a PCM fault only after the wiring and sensors pass testing.
    What would change this
    Rises if the sensor and wiring test normal. Falls if either shows a fault.

What to test first

Start at step 1. Each result tells you what it means and where to go next.

  1. Read all stored codes and freeze-frame data with a scan tool, and note any other crankshaft or camshaft codes stored with P0386.

    Low riskTool: OBD-II scan tool

    • IfOther crank or cam codes are stored

      It meansThe wiring or computer may be involved; note them for the shop.

      Go to step 2

    • IfOnly P0386 is stored

      It meansLook at the sensor wiring next.

      Go to step 2

  2. With the engine off, inspect the crankshaft sensor connector and visible harness for damage, corrosion, oil or coolant contamination and loose pins.

    Low risk

  3. Have the sensor resistance and signal checked against the maker's specification, and have the harness tested for opens and shorts.

    Best left to a shopTool: multimeter, oscilloscope

    Warning:The signal is checked while the engine is cranked, close to belts and fans, and the sensor is often in a hard-to-reach spot near the transmission. Let a shop do it.

Symptoms

  • Engine does not start
  • Hesitation or rough acceleration
  • Poor performance or reduced fuel economy

How to fix

  1. With the engine off, look over the crankshaft sensor connector and visible wiring for damage or corrosion.

Parts and cost context

  • Crankshaft position sensor:Test the sensor and wiring before replacing it. The sensor can be hard to reach, so labour varies; get a quote.

Labor varies by vehicle and shop; get a quote before you approve a repair.

Compare used part prices on PartPriceGuide

On your vehicle

We don't have reviewed vehicle-specific evidence for P0386 yet. The causes and tests above apply across vehicles.

  • P0385Crankshaft position sensor B circuit malfunction

    Same system Possible — needs testing

    P0385 is the circuit malfunction code for the same crankshaft sensor B circuit.

All Ignition and engine position sensors codes

Sources and review

  1. P0386 trouble code — TroubleCodes.net
  2. On-Board Diagnostic Trouble Codes (generic code title list) — Delaware Division of Motor Vehicles
Last reviewed
Written by
Saurabh K.
Editorial review
Pending
Technician review
Technician review pending

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Used once to identify your engine; not stored.