P0335 Code: BMW 3-Series (2019-2023) - Causes, Symptoms & Fixes

No recalls found in NHTSA database.

Note on data limits: The provided NHTSA data for 2019–2023 BMW 3-Series shows no owner complaints and no recalls for this code. The guide below combines standard OBD-II diagnostic practices with BMW-specific considerations and 2019–2023 3-Series engine layouts. If you have access to BMW-specific diagnostic tools (ISTA/DIS, ISTA flow, or similar), you may gain more precise guidance for your exact engine code (B58, B46, etc.) and model year.

CODE MEANING AND SEVERITY

• Code: P0335 — Crankshaft Position Sensor "A" Circuit Malfunction
• What it means: The engine control module (ECM/PCM) did not see a valid crankshaft position signal from the Crankshaft Position (CKP) sensor on the A circuit during a check. This can indicate a sensor problem, wiring/connectivity issue, or a failure in the signal path.
• Severity on BMW 3-Series:
  • High potential to cause no-start or stall, rough idle, misfires, or erratic engine behavior.
  • In many cases you’ll see the MIL (Check Engine Light) illuminate and the engine may run poorly or not start at all.
  • Prolonged operation with a faulty CKP signal can risk catalytic converter overheating or more severe drivability issues if the PCM mis-timings occur.
• Important note: P0335 is a generic OBD-II code. On modern BMWs it is often accompanied by additional CKP/CMP (camshaft position) or network codes if the fault is intermittent or tied to wiring/ground issues. Confirm with a full scan for related codes.

COMMON CAUSES ON BMW 3-SERIES

• Faulty CKP sensor (sensor itself is failing or at the end of its life)
• Wiring harness issue to the CKP sensor (damaged insulation, frayed wires, shorts to ground, corroded connectors)
• CKP sensor connector corrosion or poor connection
• Oil intrusion or oil contamination at or around the CKP sensor (common in engines where the sensor sits near the crank pulley or oil passages)
• Damaged or mis-seated reluctor/ring on the crankshaft (or damage to the crank pulley area where the sensor reads)
• Grounding or battery/alternator voltage issues causing insufficient sensor supply or signal integrity
• PCM/ECU fault (less common on a modern BMW, but possible)
• aftermarket modification or wiring changes affecting CKP circuit integrity

SYMPTOMS (typical for P0335 on a 2019–2023 BMW 3-Series)

• Engine fails to start or stalls, sometimes after it starts then dies
• Intermittent starting or stalling while driving
• Rough idle or misfires
• Tachometer may drop or fluctuate erratically when the engine is running
• MIL illumination with P0335 (and possibly related CKP/CMP codes)
• In some cases, the engine may run in limp mode to protect itself if multiple timing-related sensors indicate faults

DIAGNOSTIC STEPS

Safety first: Park the car on a level surface, engage parking brake, wear eye protection, and ensure the battery is in good condition. If you are uncomfortable with high-voltage systems or the engine timing area, seek professional help.

• Step 1: Confirm with a scan tool

  • Use an advanced BMW scan tool (ISTA, INPA, REALTIME OBD, etc.) to confirm P0335 and look for related codes (P0330–P0339 range, P0340–P0344 CMP/CKP related, or power/ground faults).
  • Check freeze-frame data: engine rpm at the time of fault, battery voltage, engine load, and intake air temperature. This helps determine if the issue is intermittent or tied to engine load or idle.

• Step 2: Visual inspection

  • Inspect the CKP sensor and its connector for oil leaks, dirt, corrosion, or damaged wiring.
  • Disconnect and reconnect the CKP sensor connector to ensure a solid, clean connection.
  • Inspect the wiring harness along its run to the engine block for pinched, cracked, or chafed insulation.
  • Check the ground paths for the ECM/PCM and the CKP sensor ground; ensure clean, solid ground connections.

• Step 3: Inspect sensor and reluctor area

  • If accessible, inspect the CKP sensor itself for physical damage.
  • Look for oil contamination around the sensor or on the reluctor ring (crankshaft reluctor). Clean any contamination with appropriate electronics-safe cleaner and recheck.
  • On some BMW engines, a failing reluctor or a damaged crankshaft ring can mimic a bad CKP sensor signal. If the reluctor ring is damaged or misaligned, you’ll often see persistent P0335 or related CKP codes.

• Step 4: Electrical tests (non-destructive)

  • With the ignition OFF, access the CKP sensor connector and perform a continuity/ohm check of the sensor circuit and signal return path. Compare against service documentation for expected ranges, if available.
  • Check the supply voltage to the CKP sensor (usually a 5V reference or 12V supply, depending on the sensor design in your engine). Verify there is a clean supply and that it remains within spec during crank/engine rotation.
  • Check the signal wire with an oscilloscope or a logic probe while cranking to view the CKP waveform. A healthy CKP should produce a clean, periodic waveform corresponding to crankshaft teeth/pole count. A missing waveform, irregular, or highly attenuated signal indicates sensor or wiring fault.

• Step 5: Check ignition and crank reference

  • Verify that the crankshaft position signal is present when the engine is cranking. If there is no signal, suspect CKP sensor, wiring, or reluctor ring.
  • If the CKP signal is present but the PCM still logs P0335, consider wiring faults to the ECM or a PCM fault (less common).

• Step 6: Rule-out related components

  • If you have access to BMW-specific diagnostics, look for CMP (camshaft position) sensor trends. In some BMW engines, timing and synchronization rely on both CKP and CMP signals. If CMP data shows anomalies, the fault may be timing-related rather than CKP alone.
  • If applicable, confirm there are no loose grounding points or parasitic drains that could affect sensor operation.

• Step 7: Repair or replacement

  • If CKP sensor or wiring is confirmed faulty, replace the CKP sensor and repair/replace any damaged wiring or connectors. Reattach and reseal as necessary to prevent future contamination.
  • If the reluctor ring or crankshaft related components are damaged, address those as needed, often requiring more extensive engine access.
  • After repair, clear codes, perform a cold-start and a few test drives to confirm the issue is resolved and to ensure no new codes reappear.

• Step 8: Relearn/adaptations

  • Some BMW engines require the PCM to relearn CKP sensor data or adaptations after replacement. Use the appropriate BMW diagnostic tool to run any required adaptation procedures or programming checks.

• Step 9: Verify

  • After repair, run the engine from a cold start and monitor for P0335 reoccurrence. Check for any new codes that may indicate related issues.

RELATED CODES

• CKP/CMP family and timing-sensor related codes commonly seen with CKP issues:
  • P0330–P0334 and P0336–P0339 (CKP sensor circuit and range/signal problems)
  • P0340–P0344 (CMP/Camshaft position sensor circuit issues)
  • P0335 is often seen with P0336 or P0337 if the signal path is intermittent or degraded
• Other non-CKP codes may appear if wiring or grounding problems affect multiple circuits

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices vary by region, dealer vs. indie shop, and whether OEM parts are used. The figures below are typical ballparks in USD as of 2025 and assume common 3-Series engines (B58, B46/B48 family, etc.). Labor rates vary (roughly $90–$190/hour in many areas).

• CKP sensor replacement only

  • Parts: $60–$140 (OEM vs aftermarket; Bosch/Denso equivalents often in this range)
  • Labor: 0.8–2.0 hours
  • Typical total: $180–$350
  • Notes: This assumes wiring is intact and there are no other fault conditions.

• CKP sensor replacement with wiring harness/connector repair

  • Parts: CKP sensor $60–$140; harness/connectors $20–$150 if replacements needed
  • Labor: 1.5–3.0 hours
  • Typical total: $250–$600
  • Notes: If you must repair or replace a damaged harness, costs increase accordingly.

• Reluctor ring or crankshaft area repair (rare, more invasive)

  • Parts: crankshaft timing components (as applicable) often $50–$300 for parts; may require engine access
  • Labor: 3.0–6.0 hours or more depending on access
  • Typical total: $600–$2000+
  • Notes: Involves significant labor; scope depends on engine layout and accessibility.

• PCM/ECU replacement (rare and typically avoided unless confirmed)

  • Parts: PCM replacement is expensive
  • Labor: High
  • Typical total: $1500–$4000+

• Optional service costs

  • Software/ relearn procedures using BMW-specific tools (ISTA, etc.): often included in skilled labor or an add-on fee
  • Diagnostic time if no fault found after checks: minimum diagnostic charge (usually $100–$150+)

DIY vs PROFESSIONAL

• DIY suitability:
  • Feasible for a confident DIYer with basic automotive electrical skills and access to a memory-keeping multimeter or oscilloscope, plus a BMW-compatible scan tool.
  • Pros: Lower cost, learning experience, satisfaction of fix.
  • Cons: BMWs can be tight under the hood; modern CKP circuits may require precise voltage checks and potential re-learn procedures. If you’re not comfortable with electrical systems or don’t have the right diagnostic tools, this can be risky.
• When to tackle yourself:
  • Clear symptom is a bad CKP signal with accessible sensor location; you’re comfortable disconnecting electrical connectors, performing continuity checks, and safely removing/replacing the sensor.
• Professional route:
  • Recommended if:
    • There are multiple codes, intermittent symptoms, or unclear causes.
    • You don’t have access to a BMW-specific diagnostic tool (ISTA) or an oscilloscope.
    • There is suspected crankshaft reluctor/ring damage, or timing-related work may be required.
    • The car is still under any warranty or you want a precise diagnosis with potential re-learn procedures.

PREVENTION

• Regular inspection around the CKP sensor area for oil leaks, dirt, or corrosion. Keep this area clean and dry.
• Address oil leaks promptly; oil contamination is a common cause of CKP sensor issues.
• Use high-quality replacement sensors from reputable brands (OEM or OEM-equivalent).
• Ensure proper connector seating and use dielectric grease on connectors to resist moisture and corrosion.
• Maintain the charging system and battery health; voltage dips can cause intermittent signals or misinterpretation of sensor data.
• When servicing timing-related components or crank area, follow BMW service procedures precisely, including any required adaption or relearn steps after sensor replacement.

Data limitations reminder:

• The provided data indicates no recalls or owner complaints for this combination in the NHTSA database. No recalls found in NHTSA database. The diagnostic guidance above is based on general OBD-II CKP sensor knowledge and common BMW 3-Series engine layouts (2019–2023), not on any specific recall or TSB listed in the supplied data. If you have access to OEM TSBs or dealer advisories for your exact engine code (e.g., B58 vs. B46/B48 variants), those documents may refine procedures or add model-year-specific steps.