P0336 Code: Crankshaft Position Sensor A Circuit Range/Performance
Crank signal present but implausible: damaged teeth, a slipped balancer ring or debris confuse the computer.
At a glance
Severity: Moderate
- Meaning
- Crankshaft Position Sensor A Circuit Range/Performance
- System
- Ignition & Misfire · Powertrain
- Safe to drive?
- With caution
- Typical repair cost
- $50–$1,800
- DIY difficulty
- Moderate
The engine computer doesn't just want a crank signal, it wants a specific pattern. Most tone rings have a known tooth count with a gap, such as 60 minus 2 or 36 minus 1, and the computer uses that gap once per revolution to find top dead center. P0336 sets when pulses are arriving but the pattern is wrong: too many or too few teeth between gaps, a gap that wanders, extra spikes, or an rpm reading that leaps by hundreds while the engine idles steadily. That makes it a different problem from P0335, where the signal is missing altogether. Here the sensor is usually working; something mechanical or a noise source is corrupting what it sees. The engine typically runs, but the computer may misjudge misfires and ignition timing, and it can stall when a pulse is dropped at idle.
Can I keep driving? The engine usually runs, but a corrupted crank pattern can make it stall without warning at idle or on deceleration. If the harmonic balancer is suspect, its outer ring can walk off and take the belt with it, so keep trips short and stay off the highway until it is checked.
How to read P0336
- P Powertrain
- 0 Generic (SAE)
- 3 Ignition / misfire
- 36 Specific fault
Symptoms
- Tachometer needle flickers or jumps at a steady idle
- Random misfire codes such as P0300 with healthy coils and plugs
- Stalling when coming to a stop or on deceleration
- Hesitation or a stumble under load as timing is miscalculated
- Visible wobble of the crank pulley or a new belt squeal
- Check-engine light, sometimes flickering on and off
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Harmonic balancer rubber has failed and the outer ring with the timing marks or tone ring has slipped or wobbles
- Bent, chipped or missing reluctor teeth on the flywheel, flexplate or crank-mounted wheel
- Metal debris or rust packed on a magnetic sensor tip or between the teeth
- Wrong air gap: sensor not fully seated, missing spacer, or an aftermarket sensor with a different tip length
- Inductive sensor producing weak, noisy pulses, especially once the engine is hot
- Electrical noise from a chafed plug wire or coil harness coupling into the sensor lead, or a broken shield drain
- Crankshaft position variation not relearned after sensor, balancer or engine work
Diagnosis step by step
Compare scan tool rpm with reality
Let the engine idle and watch rpm on the scanner. A steady idle that reads 700, then 1,150, then 640 within a second is a pattern fault, not a real speed change. Note the freeze frame temperature too: a balancer that slips only when hot or a sensor that gets noisy when hot narrows the search.
Tools: OBD-II scanner
Inspect the harmonic balancer
With the engine idling, watch the crank pulley from the side for wobble in the outer ring. Engine off, look for rubber squeezed out between hub and ring, cracks, and whether the factory alignment marks on hub and ring still line up. If the timing mark has moved relative to true top dead center, the ring has slipped.
Tools: Flashlight
Pull the sensor and clean the tip
A magnetic sensor tip collects swarf from a worn flexplate or starter drive, and a clump of shavings rounds off the pulses. Clean the tip, then check the air gap against the spec, which is often in the 0.5 to 1.5 mm range. A sensor that was not seated fully, or a missing spacer or shim, doubles the gap and weakens the signal.
Tools: Flashlight, Screwdriver
Check the reluctor teeth
Turn the engine by hand with a socket on the crank bolt and count teeth through the sensor hole, or inspect the flexplate through the starter opening. Look for teeth flattened by a starter pinion, a bent tooth after a flexplate replacement, or heavy corrosion filling the gaps.
Tools: Flashlight, Torque wrench
Scope the signal pattern
An inductive sensor should show a clean sine wave that grows in amplitude with rpm and a distinct missing-tooth gap once per revolution. A Hall sensor shows a square wave with a wider pulse at the gap. Extra spikes point to interference, short dips to a damaged tooth, and a gap that moves point to a slipped ring. A graphing multimeter with a min/max function is a rough substitute.
Tools: Multimeter
Look for interference on the harness
Follow the sensor wiring. If it runs beside a coil pack, plug wire or alternator cable, or the shield drain wire is broken at the connector, noise can be induced. Reroute or repair and retest.
Tools: Flashlight, Pliers
Perform the crank variation relearn
After replacing the sensor, balancer or flexplate, many manufacturers require a crankshaft position variation relearn with a scan tool so the computer knows the true tooth spacing. Skipping it can keep P0336 or misfire codes returning on an otherwise fixed engine.
Tools: OBD-II scanner
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Clean sensor tip, reseat and correct the air gap | Yes | $50–$150 |
| Replace crankshaft position sensor | Yes | $150–$350 |
| Replace harmonic balancer | No | $300–$900 |
| Replace flexplate or flywheel with a damaged reluctor | No | $700–$1,800 |
| Crankshaft position variation relearn | No | $50–$150 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Chevrolet
GM engines store a learned tooth-spacing profile for misfire detection. After a crank sensor, balancer, flexplate or engine swap, the crankshaft position variation relearn must be run with a capable scan tool, otherwise pattern and misfire codes can keep returning.
Field data
| Ram | 16 | 1500 | |
|---|---|---|---|
| Jeep | 5 | Grand Cherokee | |
| Kia | 3 | Forte, Sorento, Soul |
Source: NHTSA Complaints API (US government open data), analyzed by DTC mention.
Emissions / smog test impact
Will fail
A stored P0336 with the check-engine light on fails an OBD smog inspection. Because the misfire monitor depends on a clean crank pattern, readiness may stay incomplete until the mechanical cause is corrected and the relearn is done.
Frequently asked questions
What's the difference between P0335 and P0336?
P0335 means the computer sees no usable crank signal at all, which usually means a dead sensor or broken wire. P0336 means pulses are arriving but the pattern doesn't match the expected tooth count or gap. That shifts suspicion from the sensor toward the tone ring, balancer, air gap and interference.
Can a bad harmonic balancer really set this code?
Yes. On many engines the tone ring or the timing reference sits on the balancer's outer ring, which is bonded to the hub by rubber. When the rubber fails, the ring turns a few degrees or wobbles, and the gap no longer lands where the computer expects. A wobbling pulley and a new belt squeal are the giveaways.
I replaced the crank sensor and P0336 came back. Why?
Because the sensor was probably never the problem. Check the tone ring for damage, verify the air gap and that the new sensor has the same tip length as the original, look for shavings on the tip, and run the variation relearn if your make requires it.
Why do I get misfire codes along with P0336?
Misfire detection works by measuring tiny slowdowns of the crank between teeth. If a tooth is bent or the ring is dirty, the crank appears to slow down at the same spot every revolution, which the computer reads as a misfire in a specific cylinder. Fix the pattern fault first; the misfire codes usually disappear with it.
Is it safe to keep driving if the balancer has slipped?
No. A separated balancer ring can walk forward, shred the serpentine belt and leave you without power steering, the alternator and the water pump. Get it replaced promptly.