Failed camshaft position sensor 'B' (both sources). Damaged or broken reluctor wheel / tone ring, such as missing teeth (both sources). Poor wiring connection at the cam sensor or at the PCM, or other wiring issues. Cam sensor wiring routed too close to spark plug wires or coils, causing interference (per OBD-Codes.com). Failed engine computer (PCM), listed by RepairPal. On some vehicles without an actual cam sensor, severe misfiring from bad spark plugs, plug wires or coils (per OBD-Codes.com).

Repair wiring or connectors, or reroute wiring away from ignition components. Replace camshaft position sensor 'B' if everything else checks out (the most common repair listed by RepairPal). Replace a damaged reluctor wheel / tone ring, which may mean removing the camshaft or intake manifold depending on the engine. Fix misfire causes (plugs, plug wires, coils) on vehicles where the code points to misfiring. Diagnose and replace the PCM only after the sensor, wiring and tone ring check out.

P0366🔧 Engine timing / cam and crank sensorsStop and fix promptly

P0366: Camshaft Position Sensor B Range/Performance (Meaning, Causes, Fixes)

Q: What does P0366 mean?

P0366 means the engine computer saw a signal from camshaft position sensor 'B' that doesn't match what it expects, or saw an irregular signal or none at all. Common causes are the sensor itself, its wiring or connections, wiring picking up interference from ignition parts, or a damaged tone ring (reluctor wheel), so check those before simply swapping the sensor. The camshaft position sensor reads the exact rotational position of the camshaft as teeth on a reluctor wheel (tone ring) pass by it. RepairPal explains that the engine computer (PCM) uses this signal to control the fuel injectors and ignition coils, and sets P0366 when it detects an irregular signal or no signal. OBD-Codes.com describes it as the PCM finding the 'B' cam signal inconsistent with what it should be, and notes the code can also be set by long cranking periods. P0366 is a generic code for 1996-and-newer OBD-II vehicles. It's the 'range/performance' code for sensor 'B', while P0365 is the general circuit code for the same sensor and P0369 is the intermittent code. Which physical sensor is 'B' depends on the engine, so check your vehicle's service information. The sources differ in a few ways. OBD-Codes.com titles it 'Bank 1' (the bank with cylinder #1), while RepairPal lists no bank. RepairPal rates it Urgent, while OBD-Codes.com says the car will likely run, often with no symptoms beyond the warning light. OBD-Codes.com also notes that on some vehicles without an actual cam sensor, this code points to bad misfiring from worn spark plugs, plug wires or coils. Neither source gives a repair cost.

Q: Can I keep driving with P0366?

Stop and fix promptly. Get this diagnosed promptly. RepairPal rates P0366 'Urgent', its highest level, meaning immediate action is recommended. OBD-Codes.com is milder: it says the car will likely still run because the fault is often intermittent and the engine computer can use a limp-home mode, but it also lists a possible no-start. Don't count on the car for a long trip until it's checked, since it may not restart.

Reviewed 2026-10-23 · Based on 2 cited source(s)

What P0366 means

The camshaft position sensor reads the exact rotational position of the camshaft as teeth on a reluctor wheel (tone ring) pass by it. RepairPal explains that the engine computer (PCM) uses this signal to control the fuel injectors and ignition coils, and sets P0366 when it detects an irregular signal or no signal. OBD-Codes.com describes it as the PCM finding the 'B' cam signal inconsistent with what it should be, and notes the code can also be set by long cranking periods. P0366 is a generic code for 1996-and-newer OBD-II vehicles. It's the 'range/performance' code for sensor 'B', while P0365 is the general circuit code for the same sensor and P0369 is the intermittent code. Which physical sensor is 'B' depends on the engine, so check your vehicle's service information. The sources differ in a few ways. OBD-Codes.com titles it 'Bank 1' (the bank with cylinder #1), while RepairPal lists no bank. RepairPal rates it Urgent, while OBD-Codes.com says the car will likely run, often with no symptoms beyond the warning light. OBD-Codes.com also notes that on some vehicles without an actual cam sensor, this code points to bad misfiring from worn spark plugs, plug wires or coils. Neither source gives a repair cost.

Severity: can I keep driving?

Stop and fix promptly

Get this diagnosed promptly. RepairPal rates P0366 'Urgent', its highest level, meaning immediate action is recommended. OBD-Codes.com is milder: it says the car will likely still run because the fault is often intermittent and the engine computer can use a limp-home mode, but it also lists a possible no-start. Don't count on the car for a long trip until it's checked, since it may not restart.

Common symptoms

Check engine light on
Engine may not start (both sources)
Poor fuel economy or increased fuel consumption (both sources)
Decreased engine performance (listed by RepairPal)
Sometimes no other noticeable symptoms, since the fault is often intermittent (per OBD-Codes.com)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Failed camshaft position sensor 'B' (both sources)
Damaged or broken reluctor wheel / tone ring, such as missing teeth (both sources)
Poor wiring connection at the cam sensor or at the PCM, or other wiring issues
Cam sensor wiring routed too close to spark plug wires or coils, causing interference (per OBD-Codes.com)
Failed engine computer (PCM), listed by RepairPal
On some vehicles without an actual cam sensor, severe misfiring from bad spark plugs, plug wires or coils (per OBD-Codes.com)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

Read all stored codes. Misfire codes, a crankshaft sensor code (such as P0335) or other cam sensor codes (P0340, P0365, P0369) alongside P0366 change where you look first.
Find out which sensor is 'B' on your engine from the service information, then inspect its connector and wiring for burn marks, melting, chafing, corrosion or loose pins.
Make sure the sensor wiring isn't routed close to the ignition coils or spark plug wires, which OBD-Codes.com says can cause interference.
Inspect the sensor for damage and, if you can see it through the sensor port, the reluctor wheel for missing or damaged teeth.
Clear the code after any repair and see whether it returns before buying more parts.

Typical fixes

Repair wiring or connectors, or reroute wiring away from ignition components
Replace camshaft position sensor 'B' if everything else checks out (the most common repair listed by RepairPal)
Replace a damaged reluctor wheel / tone ring, which may mean removing the camshaft or intake manifold depending on the engine
Fix misfire causes (plugs, plug wires, coils) on vehicles where the code points to misfiring
Diagnose and replace the PCM only after the sensor, wiring and tone ring check out

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

The engine cranks but won't start, or stalls while driving
You've replaced the cam sensor and the code came back
The reluctor wheel needs inspection or replacement inside the engine
You can't tell which sensor is 'B' on your engine, or testing needs wiring diagrams and an oscilloscope

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Will a new camshaft sensor fix P0366?

Often, but not always. OBD-Codes.com says replacing the sensor often fixes it, but recommends checking wiring routing, connections and the reluctor wheel first. RepairPal also lists a broken tone ring, wiring and the PCM as causes.

Can I drive with P0366?

The sources disagree on how serious it is. RepairPal rates it 'Urgent', while OBD-Codes.com says the car will likely run, sometimes in limp-home mode. Both list a possible no-start, so have it checked soon rather than risk getting stranded.

What's the difference between P0365 and P0366?

Both are for camshaft position sensor 'B'. P0365 is a general circuit fault, while P0366 is a range/performance fault, meaning the signal is there but doesn't look the way the computer expects.

Sources

Last reviewed 2026-10-23. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.