Faulty B camshaft position sensor or damaged sensor wiring connector; Contaminated or degraded engine oil affecting VANOS solenoid operation; Sticking or failed VANOS solenoid on the affected camshaft; Timing chain wear or stretched chain causing cam-to-crank misalignment; Failed camshaft timing phaser or mechanical VANOS unit; Engine control module software issue requiring update or reprogramming

DTC codes / BMW codes / P1317

P1317 · BMWB Camshaft Position Plausibility

Q: What does code P1317 mean?

B Camshaft Position Plausibility. P1317 on BMW vehicles indicates that the engine control module has detected an implausible signal from the B camshaft position sensor, meaning the reported cam timing does not match the expected correlation with the crankshaft signal. The computer compares the cam and crank signals during startup and running to verify that the variable valve timing system is mechanically and electrically sound.

P1317 on BMW vehicles indicates that the engine control module has detected an implausible signal from the B camshaft position sensor, meaning the reported cam timing does not match the expected correlation with the crankshaft signal. The computer compares the cam and crank signals during startup and running to verify that the variable valve timing system is mechanically and electrically sound.

SystemPowertrain

Code typeBMW specific

SeverityMedium

Fix difficultyProfessional

AreaIgnition system and misfire

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or intermittent stalling, especially when the engine is cold
Reduced engine performance or limp mode under acceleration
Poor fuel economy or increased emissions
Difficulty starting or extended cranking time
Occasional misfire or hesitation during light throttle

Common causes, most likely first

Faulty B camshaft position sensor or damaged sensor wiring connector
Contaminated or degraded engine oil affecting VANOS solenoid operation
Sticking or failed VANOS solenoid on the affected camshaft
Timing chain wear or stretched chain causing cam-to-crank misalignment
Failed camshaft timing phaser or mechanical VANOS unit
Engine control module software issue requiring update or reprogramming

How to diagnose and fix it

Perform a visual inspection of the B camshaft sensor wiring and connector for chafing, corrosion, or loose pins
Check engine oil level and condition; change oil and filter if overdue or contaminated
Use a scan tool to read live camshaft and crankshaft position data and compare commanded versus actual cam timing
Test the B camshaft position sensor signal with an oscilloscope or swap with a known-good sensor if accessible
Inspect and test the VANOS solenoid for the affected camshaft, cleaning or replacing if faulty
Verify timing chain condition and camshaft timing marks; repair mechanical timing issues if found
Update engine control module software if no other faults are found and the code persists

Cam sensor code often misdiagnosed as sensor failure

A stretched timing chain on higher-mileage BMW engines frequently sets P1317 before any chain noise is audible, so always verify timing marks before replacing sensors.
Oil sludge or infrequent oil changes can clog VANOS solenoid screens and cause implausible cam signals without any electrical fault in the sensor circuit.
The B camshaft sensor on some BMW engines is difficult to access, leading technicians to replace the easier-to-reach A sensor by mistake and leave the fault unresolved.
Intermittent P1317 can be caused by a failing camshaft phaser bolt or worn VANOS seals that only misbehave when oil pressure is low at idle.
After any timing chain or VANOS repair, the engine control module adaptation values must be cleared and a relearn drive cycle performed to prevent false recurrence.

Can I keep driving with P1317?

You can usually drive the vehicle short distances at moderate speeds, but avoid hard acceleration and prolonged idling until the fault is diagnosed. If the engine runs roughly, stalls, or enters limp mode, stop driving and arrange a professional inspection to prevent further damage.

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.