Faulty crankshaft position sensor (most common); Damaged or corroded sensor wiring or connector; Metal debris or damage on the crankshaft reluctor wheel; Worn or stretched timing chain affecting camshaft-to-crankshaft correlation; Faulty camshaft position sensor (less common); ECM software issue or internal fault (rare)

DTC codes / BMW codes / P1396

P1396 · BMWCrankshaft Position Sensor Segment Timing Plausibility

Q: What does code P1396 mean?

Crankshaft Position Sensor Segment Timing Plausibility. P1396 on BMW vehicles indicates that the engine control module (ECM) has detected an implausible signal from the crankshaft position sensor during the segment timing self-check. The ECM compares the crankshaft signal against the camshaft signal and expects a specific relationship; when the pattern falls outside the allowed tolerance, this code is stored.

P1396 on BMW vehicles indicates that the engine control module (ECM) has detected an implausible signal from the crankshaft position sensor during the segment timing self-check. The ECM compares the crankshaft signal against the camshaft signal and expects a specific relationship; when the pattern falls outside the allowed tolerance, this code is stored.

SystemPowertrain

Code typeBMW specific

SeverityMedium

Fix difficultyIntermediate

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Intermittent engine stumble or misfire at idle or under light load
Difficulty starting, especially when the engine is cold or after sitting
Rough running or hesitation during acceleration
Stalling at low speeds or when coming to a stop
Reduced engine performance and poor fuel economy

Common causes, most likely first

Faulty crankshaft position sensor (most common)
Damaged or corroded sensor wiring or connector
Metal debris or damage on the crankshaft reluctor wheel
Worn or stretched timing chain affecting camshaft-to-crankshaft correlation
Faulty camshaft position sensor (less common)
ECM software issue or internal fault (rare)

How to diagnose and fix it

Perform a visual inspection of the crankshaft sensor and its wiring for damage or corrosion
Check for technical service bulletins (TSBs) related to the code and ECM software updates
Use a scan tool to monitor live crankshaft and camshaft position signals for consistency
Test the crankshaft position sensor with a multimeter or oscilloscope for proper signal output
Inspect the reluctor wheel for debris or damage and clean or replace as needed
Verify timing chain condition and alignment if other causes are ruled out
Replace the crankshaft position sensor if tests indicate failure, then clear the code and verify repair

Crankshaft Sensor Segment Timing Pitfalls

A stretched timing chain can cause P1396 without any sensor fault, as the camshaft-to-crankshaft relationship drifts beyond tolerance.
Debris on the crankshaft reluctor wheel is a commonly overlooked cause that can mimic a failed sensor.
The code may set intermittently due to heat-related sensor failure, so testing when the engine is warm is crucial.
Replacing the sensor without checking the reluctor wheel or timing chain often leads to a quick return of the code.
Some BMW models require ECM software updates to correct false P1396 triggers, so always check for bulletins first.

Can I keep driving with P1396?

If the engine runs normally, you can drive cautiously to a repair shop, but avoid heavy acceleration or long trips. If the engine stalls, misfires severely, or loses power, stop driving and have the vehicle towed to prevent safety risks.

Tools that help

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Guidance is general and written for BMW vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.