P0335 Code: Mazda Mazda6 (2022-2024) - Causes, Symptoms & Fixes

Below is a comprehensive diagnostic guide for P0335 (Crankshaft Position Sensor “A” Circuit Malfunction) as it relates to 2022–2024 Mazda Mazda6. This guide follows the provided data constraints: no NHTSA complaints and no recalls found for this exact model/year/issue combination in the supplied data. Data limitations are noted where relevant.

CODE MEANING AND SEVERITY

• Code meaning: P0335 = Crankshaft Position Sensor “A” Circuit Malfunction. The engine control module (ECM/PCM) is not receiving a valid crankshaft position (CKP) signal from the sensor, or the signal is out of expected range.
• Why it matters: The CKP sensor provides critical timing information used to control ignition and fuel injection. Without a reliable CKP signal, the engine may fail to start, stall, run poorly, or go into limp/forced-mode. In short, this is a high-severity diagnostic that can leave the vehicle inoperable or unsafe to drive if not addressed.
• Data caveat: The provided data set shows no NHTSA complaints for this issue on 2022–2024 Mazda6 and no recalls. No complaints data means real-world occurrences may exist outside the dataset or be underreported.

COMMON CAUSES ON MAZDA MAZDA6

• Faulty CKP sensor itself: Wear, internal failure, or exposure to contaminants.
• Wiring harness problems: Damaged, frayed, or routed-harness chafing that opens or shorts the CKP circuit.
• Poor electrical connections: Corroded, bent, or loose pins in the CKP sensor connector or ECM/PCM connector.
• Oil or contamination: Oil leaks or accumulation around the CKP sensor can affect sensing, especially if the sensor is located near an oil-filled area.
• Sensor grounding or 5V reference issues: Faulty ground or 5-volt reference to the CKP sensor can cause signal abnormality.
• PCM/ECM fault: In rare cases, the engine control module itself may have an internal fault affecting CKP signal processing.
• Mechanical timing concerns: In rare cases, timing chain/brequency ring (reluctor) damage or misalignment can prevent a proper CKP signal from being generated or read correctly.
• Intermittent signal: Wiring or connector movement/vibration can cause intermittent loss of signal which triggers DTCs intermittently.

SYMPTOMS

• The engine may fail to start or crank without starting.
• Stalling or rough running once started.
• Intermittent no-start or intermittent stalling.
• Check Engine Light (CEL) on with P0335 stored or pending.
• Possible limp mode or reduced power operation in some cases.
• No obvious mechanical damage on the outside; symptoms may appear alongside other CKP-related codes if present.

DIAGNOSTIC STEPS

Note: Perform in a safe environment with proper PPE. If you’re not comfortable performing these steps, seek a qualified technician.

A. Preparation

• Ensure vehicle is on a level surface, in Park (automatic) or Neutral (manual), with parking brake engaged.
• Gather: scan tool capable of CKP data, digital multimeter, backprobe leads, a tow/wrench set, and service manual wiring diagrams for the CKP circuit (Mazda-specific diagrams are ideal).

B. Confirm DTC and data

• Use an OBD-II scanner to confirm P0335 is present and note any related codes (e.g., P0336, P0337, P0338, P0339 if present).
• Check freeze-frame data for engine RPM, engine load, and timing context when the fault occurs.

C. Visual inspection

• Inspect CKP sensor and its connector for obvious damage, corrosion, oil contamination, or moisture.
• Check for damaged or pinched wiring along the CKP harness path, especially near belts, pulleys, exhaust components, or mounting points.
• Look for oil leaks around the sensor area or the front crank pulley area; oil can degrade sensor performance.
• Inspect the ECM/PCM connector for corrosion or bent pins.

D. Electrical tests (needs appropriate tools)

• Power/ground check:
  • With the key ON (engine off), backprobe the CKP sensor connector to verify:
    • 5V reference on the CKP signal circuit (or the reference circuit specified by Mazda wiring diagrams).
    • A solid ground on the CKP ground circuit.
  • If there is no 5V reference or poor ground, repair the wiring or connector accordingly.
• Signal circuit test:
  • Backprobe the CKP signal wire while cranking the engine. You should observe a pulsed signal corresponding to the crank’s rotation (frequency/pulse train).
  • If you cannot observe a signal, suspect the CKP sensor, its connector, or the wiring back to the PCM.
  • If a signal is present but erratic, check for noise, voltage drop, or intermittent grounding.
• Continuity and resistance checks:
  • Check resistance between the CKP sensor signal wire and ground as specified by Mazda service data (compare to spec).
  • Check for short to voltage or short to ground on the CKP circuit.
• If equipped, use a scope:
  • A waveform on the CKP sensor should show regular pulses as the engine attempts to crank. A missing or irregular waveform indicates sensor, wiring, or timing issues.

E. Mechanical considerations

• If electrical tests fail to locate a fault, consider mechanical causes:
  • Inspect the crank reluctor ring or gear for damage or misalignment.
  • If timing chain/belt tensioner or guides have issues, timing accuracy can be compromised; this is more severe and often associated with other diagnostics (e.g., P0016/P0017 family) but can influence CKP signal reliability.
• Compression test can help rule out a mechanical engine failure that might masquerade as CKP issues.

F. Reproduce and confirm

• After repairs or part replacements, clear DTCs and perform a road test or repeated cranking sessions to confirm the DTC does not return.
• Reconnect the scanner to monitor CKP signal during a test drive or cranking event to verify clean, stable pulses.

G. If CKP sensor and wiring tests pass but DTC persists

• Consider ECM/PCM fault or needing software/firmware updates as per Mazda service bulletins (note: only cite actual recalls/TSBs if provided; the data set does not list recalls, so you’d verify via Mazda service information or dealer-specific TSBs if needed).
• Re-check all connections and re-test after a fresh battery connection or power cycle.

RELATED CODES

• P0335 Crankshaft Position Sensor “A” Circuit Malfunction (main)
• P0336 Crankshaft Position Sensor A Circuit Range/Performance
• P0337 Crankshaft Position Sensor A Circuit Low Input
• P0338 Crankshaft Position Sensor A Circuit High Input
• P0339 Crankshaft Position Sensor A Circuit Intermittent
  Note: These are typical related CKP codes that could appear in conjunction or sequentially if the sensor or circuit conditions worsen or intermittently fail.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Important: Prices vary by region, shop, and whether Mazda OEM parts are used. The ranges below are approximate and intended to illustrate typical costs.

• CKP sensor replacement

  • Parts: $40–$120
  • Labor: $60–$180
  • Estimated total: $100–$300
  • Notes: This is the most common fix if the sensor itself is proven faulty or has failed.

• CKP sensor harness/connector repair or replacement

  • Parts: $10–$60 (if only connector or loom clamp is replaced)
  • Labor: $100–$250
  • Estimated total: $110–$310
  • Notes: If wiring is damaged, you may repair with splices or replace a section of loom.

• PCM/ECM repair or replacement (rare, but possible)

  • Parts: $300–$1,400 (reconditioned or OEM PCM)
  • Labor: $150–$400
  • Estimated total: $450–$1,800
  • Notes: Most CKP problems are resolved with sensor/wiring fixes; PCM replacement is a last resort.

• Timing chain/belt, tensioner, or relator-related repair (if CKP issue is caused by timing concerns)

  • Parts: $150–$800
  • Labor: $300–$1,000
  • Estimated total: $450–$1,800
  • Notes: If a mechanical race or misalignment is found, this can be a major repair.

• Total repair scenario (worst-case with multiple issues)

  • Parts: $400–$2,000
  • Labor: $200–$1,000
  • Estimated total: $600–$3,000
  • Notes: Rarely needed, but possible if multiple systems are affected or PCM programming is required.

DIY VS PROFESSIONAL

• DIY-friendly?
  • Replacing a readily accessible CKP sensor is often DIY-friendly for a mechanically inclined person with basic tools. Access may vary by engine layout; some Mazdas position the CKP sensor behind belts or pulleys requiring belt removal.
  • Electrical checks (5V reference, ground, continuity, and diagnostic oscilloscope or scan tool data) require knowledge and proper equipment (multimeter, backprobe leads, possibly an oscilloscope or a high-quality scan tool that can display CKP data).
  • Cautions: Incorrect reassembly can cause wiring damage, or you may misread a signal if you don’t compare to Mazda’s factory specifications.
• Professional considerations?
  • A professional technician has the proper wiring diagrams for the CKP circuit, the correct torque specs, and specialized diagnostic tools to verify CKP signals on Mazda6 models efficiently.
  • If the CKP sensor tests pass but the code persists, a professional may perform deeper diagnostics (PCM, software updates, or timing-related checks) with proper software.

PREVENTION

• Regularly check for oil leaks near the CKP sensor area; oil contamination can degrade sensor performance.
• Keep the CKP sensor and its connector clean and dry; avoid solvent exposure that could degrade seals or plastic connectors.
• Inspect wiring harnesses for signs of abrasion, heat damage, or pin corrosion. Reroute or protect harnesses from moving components or heat sources.
• Ensure proper engine maintenance (oil changes, filter changes, and module ground integrity) to keep the ECM/CKP interface stable.
• If you have a history of CKP-related faults, consider periodic checks during major service intervals, and replace the CKP sensor if it has shown signs of wear or intermittent signal loss.
• Use OEM or high-quality aftermarket connectors and gaskets to maintain a reliable electrical connection.

Important data note

• The provided data indicates “No NHTSA complaints found for this make/model/year/issue combination” and “No recalls found in NHTSA database.” This means the dataset contains no official complaints/recalls for P0335 on 2022–2024 Mazda6 in the supplied records. Real-world occurrences may exist that are not captured in this dataset. Always verify with Mazda’s latest service literature, TSBs, and your local dealer if you suspect a known issue or a customer service program.