P0340 Code: Toyota Camry (2018-2024) - Causes, Symptoms & Fixes

Comprehensive diagnostic guide for OBD-II code P0340 on 2018-2024 Toyota Camry

Important data notes (transparency about the source you provided)

• The real NHTSA data you provided includes one owner complaint for P0442 (not P0340) and a note that there are no recalls for this Camry model in the database.
• There are no P0340-specific complaints or recalls in the data you supplied. This guide uses general Toyota Camry knowledge for P0340 diagnosis and reference points, with 2025 price estimates for repairs. If you have data for P0340 from a broader source, those numbers may differ.
• If you do see any P0340 in your own vehicle, treat it as a fault in the Camshaft Position Sensor circuit, which is a signal used by the ECU to synchronize ignition and fuel injection to the camshaft position.

CODE MEANING AND SEVERITY

• Code: P0340 — Camshaft Position Sensor Circuit Malfunction.
• What it means: The engine control module (ECM/PCM) detects an abnormal condition in the camshaft position (CMP) sensor circuit. The CMP sensor provides the ECM with the camshaft’s position information, which is critical for proper ignition timing and fuel injection timing.
• Severity and symptoms: This code can cause misfires, poor idle, reduced power, hard starting or no-start, and in some cases stalling. The check engine light (MIL) is typically illuminated. In some vehicles, the ECM may set a limp-mode strategy to protect the engine, leading to limited power and drivability concerns.
• Notes for Camry: On Camry models, the CMP sensor is essential for precise variable valve timing control and ignition timing. If you have a V6 with two cam sensors, P0340 generally relates to the Bank 1 CMP signal; other CAM sensors (e.g., Bank 2) may trigger related codes (P0341, P0345, etc.) depending on the year and engine variant. Always confirm with the service manual for your exact engine code.

COMMON CAUSES ON TOYOTA CAMRY

• Faulty camshaft position sensor (CMP) itself.
• Damaged, corroded, or loose CMP sensor electrical connector or wiring harness (insulation wear, oil contamination, coolant leaks).
• Faulty or degraded wiring between the CMP sensor and the ECU (shorts, open circuits, high resistance).
• CMP sensor reluctor ring or camshaft timing gear/reluctor issues leading to improper signal (timing chain/belt wear, stretched chain, failed tensioner, or camshaft timing misalignment).
• Timing issues: cam timing out of spec due to timing chain/belt wear, chain tensioner failure, or previous improper timing service.
• Electrical supply/ground problems: poor 5V reference or ground to the CMP signal circuit (voltage drop under load).
• PCM/ECM fault (less common): internal sensor circuit fault or corrupted firmware.
• Related sensor interactions: issues with variable valve timing (VVT) solenoids or oil pressure affecting CMP signal stability.
• Battery/charging problems: low voltage or unstable electrical supply can cause intermittent CMP readings.
• Intermittent faults may be hard to reproduce and can cause repeated DTCs only under certain operating conditions (cold start, high load, temperature changes).

SYMPTOMS TO EXPECT WITH P0340

• Check Engine Light (MIL) on or flashing in some drivability scenarios.
• Misfiring or rough idle.
• Engine stumbles, misfires under load, or reduced power.
• Hard starting or no-start in some cases.
• Decreased fuel economy.
• Intermittent drivability issues that may appear during highway driving or at idle, depending on fault timing and related circuits.
• Tachometer behavior may be erratic if the CMP signal is erratic (not always present).

DIAGNOSTIC STEPS (systematic approach)

Note: The following steps prioritize safety and a logical progression without assuming timing chain work unless indicated by the fault pattern.

A. Prepare and verify

• Retrieve DTCs and Freeze Frame data with a capable OBD-II/scan tool. Note any related codes (P0335, P0336, P0341, P0345, P0365, etc.) that might point to a broader CMP/Timing issue.
• Confirm current driving condition when the code set (cold start, warm idle, under load, etc.).
• Check battery voltage and charging system. A weak battery or failing alternator can cause sensor signals to be unreliable.

B. Visual and basic electrical inspection

• Inspect CMP sensor connector and wiring for damage, corrosion, oil or coolant contamination, loose pins, bent pins, or melted insulation.
• Inspect the CMP sensor mounting surface and sensor body for oil leakage or contamination (oil pressure can affect sensor performance in some designs).
• If available, inspect the CMP sensor wiring harness through its entire length for chafing and replace any damaged portion.
• Check for excessive vacuum/other engine service issues that could affect timing or sensor readings.

C. Data validation with scan tool

• With the engine cranking and at running temperature, monitor CMP sensor live data (often labeled CMP, Cam Position, or SP1/SP2 lines depending on the tool). You should see a stable waveform or timing signal as the camshaft rotates.
• If a live CMP signal is present but inconsistent or missing, suspect the CMP sensor or its circuit.
• Check for 5V reference (Vref) and ground stability from the PCM to the CMP sensor. A poor ground or a drifting Vref can cause intermittent readings.
• If the CMP signal is present but out of spec (unexpected pulse timing, wrong polarity, or severely jittery), investigate the sensor and related wiring, and consider timing issues.

D. Inspection of timing and mechanical integrity (when indicated)

• If there are accompanying codes that suggest mis-timing (P0010/P0011 related to VVT or timing control) or if the engine shows symptoms consistent with a timing issue, the timing chain/belt, guides/tensioners, and cam/crank sprockets should be inspected.
• In severe cases or if the chain has jumped, you may need to remove the valve cover and check timing marks, camshaft timing relation, and chain tensioner condition. This is typically a job for a qualified technician.

E. Related tests if no obvious cause found

• If CMP sensor and wiring test OK, consider testing the crankshaft position sensor (CKP) and its circuit (P0335, P0336) to rule out a shared ECU timing issue.
• Consider ECU/PCM software updates if available through a Toyota dealer (though this is not a fix you can observe without dealer tools; verify applicable TSB/updates for your VIN).
• Check for oil pressure issues or abnormal oil flow that could affect VVT solenoids and related timing control if the engine uses such features.

F. Repair decision and verification

• If CMP sensor is confirmed faulty (bad readings, dead signal, or poor continuity to PCM), replace CMP sensor and clear codes. Reconnect harness, ensure clean connections, and verify with a test drive.
• If wiring is damaged, repair/replace wiring harness segments and connectors, re-test, and re-check for DTCs.
• If timing components are suspect (chain, tensioner, guides), perform the appropriate timing service per Toyota service procedures. This may require removing service covers and setting timing marks with precision. This is typically a more labor-intensive repair.
• After any repair, clear DTCs, run the engine through a full drive cycle (idle, acceleration, and cruise), and confirm the DTC does not return.

RELATED CODES (may accompany P0340)

• P0341: Camshaft Position Sensor Circuit Range/Performance (Bank 1 or Bank 2 depending on engine)
• P0345: Camshaft Position Sensor Circuit Range/Performance (Bank 2) on some V6 configurations
• P0335: Crankshaft Position Sensor Circuit Malfunction
• P0330: Knock Sensor Circuit Malfunction
• P0010 / P0011: Timing/Variable Valve Timing (VVT) control issues
• P0300: Random/Multiple Cylinder Misfire (may appear if CMP signal is erratic)
  Note: Exact related codes can vary by engine variant (4-cylinder vs V6) and model year. Refer to the original Toyota service information for your VIN if needed.

REPAIR OPTIONS AND COSTS (2025 prices)

Prices vary widely by region, vehicle specifics, and labor rates. Estimated ranges below are typical for the United States and reflect parts, labor, and basic shop markup.

• Camshaft Position Sensor replacement (single CMP sensor)

  • Parts: $25–$120
  • Labor: 0.5–1.0 hours
  • Total estimate: $100–$250
  • Notes: Labor assumes simple sensor replacement with easy access. If replacing requires removing components or sensor is difficult to access, labor could rise.

• CMP sensor wiring/connector repair

  • Parts: minimal (if only harness repair is needed)
  • Labor: 0.5–2.0 hours
  • Total estimate: $100–$350
  • Notes: If extensive harness repair is needed, cost can rise.

• Timing chain/belt and tensioner/guide service (if timing is suspected or proven faulty)

  • Parts: $100–$500 (depends on components replaced)
  • Labor: 4–8+ hours
  • Total estimate: $800–$2,500
  • Notes: This is a major repair that should be performed by a skilled technician. In Camry engines using a timing chain system, issues typically involve chain wear, tensioner, or guides.

• PCM/ECM replacement or reprogramming (rare)

  • Parts: $600–$1,200 (new PCM)
  • Labor: 1–3 hours (plus programming time)
  • Total estimate: $700–$1,800
  • Notes: PCM replacements require initialization and software programming. This is usually a last-resort option after sensor and harness testing.

• Miscellaneous (upstream sensor tests, gaskets, seals, oil leaks)

  • Parts: $10–$100
  • Labor: 0.5–2.0 hours
  • Total estimate: $60–$350

DIY VS PROFESSIONAL

• DIY viability: If you have a solid understanding of automotive electrical systems, a capable scan tool, a multimeter/oscilloscope, and a basic set of hand tools, replacing a CMP sensor is a feasible DIY task on many Camry engines. Steps typically involve disconnecting the battery, removing the sensor, cleaning the mounting area, installing the new sensor, and verifying with a drive test. Be sure to follow Toyota service manual torque specs and safety precautions.
• When to call a pro: If you suspect timing chain/belt issues, cam/crank timing misalignment, VVT system trouble, or PCM concerns, or if the CMP signal is not readily accessible, a professional with Toyota-specific tooling and experience is advised. Timing work is not a routine DIY task for many home mechanics and may require special tools and procedures.
• Important safety notes: Disconnect the battery before disconnecting electrical connectors; never work with the engine running when performing electrical tests on sensors; proper torque and electrical connector seating are essential to avoid future misreads.

PREVENTION AND BEST PRACTICES

• Regular maintenance: Change engine oil with the correct grade and change intervals to maintain healthy cam timing lubrication and VVT operation. Low or dirty oil can affect sensor readings in some VVT systems.
• Clean electrical connections: Periodically inspect and clean the CMP sensor wiring harness connectors; use dielectric grease on connectors to prevent corrosion.
• Avoid contamination: Keep oil leaks and coolant leaks checked and repaired promptly, as exposure to oil/coolant can contaminate sensor connectors and wiring.
• Battery health: Maintain a healthy battery and charging system to prevent voltage dips that could trigger intermittent CMP sensor faults.
• Address issues early: If you notice rough idle, misfires, or poor acceleration, diagnose and fix early. Prolonged misfires can damage catalytic converters and spark plugs.
• Software updates: Check for any available ECU/PCM updates from Toyota for your VIN. These updates sometimes address sensor interpretation and timing logic (performed by a dealer or authorized shop).

Data limitations recap

• Your dataset does not contain P0340-specific complaints or recalls for the 2018-2024 Camry. The guide above relies on general Camry/CMP sensor diagnostic knowledge and common fault patterns. If you have additional data, those could influence the recommended steps or costs.

If you’d like, I can tailor this guide to your exact Camry engine variant (2.5L 4-cyl, 3.5L V6, or hybrid) and your VIN, which would help refine the CMP sensor location, possible related codes, and timing considerations.