P0385 Code Meaning and Next Steps

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

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
Free - no tools
Check whether the engine has a hard-start, stall, or rough-run symptom with the code
2
Free - no tools
Inspect the sensor connector and harness for oil, heat, or abrasion damage
3
Basic tool needed
Look for related crankshaft, camshaft, or misfire codes that may help with diagnosis
4
Basic tool needed
If scan data is available, compare crank signal stability with engine RPM behavior
5
Basic tool needed
Notice whether the code appeared after timing work or sensor replacement

If the code returns

-If the signal is missing or erratic at the sensor, wiring or the sensor itself rises on the list.
-If the signal looks okay but the engine still has timing problems, inspect the tone wheel and mechanical side.
-If the code returns after connector repair, recheck sensor fit and wiring routing.

Background

What this code means

P0385 is a generic OBD-II code for a crankshaft position sensor B circuit malfunction.

The engine controller needs a believable crank signal to manage ignition and fuel timing. If sensor B is not behaving correctly, the fault may be in the sensor itself, the wiring, or the tone wheel it reads.

Diagnosis

Common causes

Most common

Failed crankshaft position sensor B

The sensor may no longer report a stable crank signal.

Common

Wiring or connector damage

Heat, oil, or corrosion can interrupt the sensor circuit.

Common

Damaged tone wheel

The reference wheel may not be presenting a good signal.

Possible

Sensor gap or mounting issue

A poor gap or loose mount can make the signal unreliable.

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 stalling or no-start 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 unstable or missing.

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.

Related OBD codes

P0386

P0386 means the crankshaft position sensor B signal is out of range or not believable.

P0387

P0387 means the crankshaft position sensor B signal is too low or missing.

P0388

P0388 means the crankshaft position sensor B signal is too high.

Source notes

Generic OBD-II (SAE J1979 / ISO 15031-5). P0385 was seeded from dtcdb and then expanded around crankshaft position sensor B circuit 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

P0385 - The Crankshaft Position Sensor B Circuit Has a Malfunction