P0340 Code: Honda CR-V (2017-2023) - Causes, Symptoms & Fixes

Diagnostic guide: P0340 on 2017–2023 Honda CR-V

Data note

• REAL NHTSA DATA provided: No owner complaints found for this make/model/year/issue combination. No recalls found in NHTSA database.
• Therefore, this guide does not cite recalls or TSBs. All cost estimates and steps are based on general automotive knowledge and typical repair practices for this code and vehicle family. Data limitations: there are no official complaint counts or recalls in the supplied data to anchor statistics; the guide emphasizes practical diagnosis and common-sense repair approaches.

CODE MEANING AND SEVERITY

• What the code means: P0340 = Camshaft Position Sensor Circuit Malfunction. The engine computer (PCM) monitors the camshaft position sensor (CMP) signal to determine the camshaft’s position and timing relative to crank position. When the PCM detects an out-of-range, missing, or erratic CMP signal, it stores P0340 and often illuminates the check engine light.
• How severe is it: Moderate to potentially serious. A failing or intermittent CMP signal can cause misfires, rough idle, stalling, hard starting, or no-start conditions. In some cases the engine may run poorly or go limp rather than stall. Because timing reference is essential for proper fuel injection and ignition timing, ignoring P0340 can lead to poor drivability and potential engine damage if timing becomes severely off (especially in interference engines). The provided data set shows no NHTSA complaints or recalls for this combination, but that does not eliminate real-world risk in individual vehicles.
• Important note on data: There are no recalls or complaints in the provided data, so no statistics or campaign notes are available to frame this guide against. Use service information and diagnostic testing to assess your specific vehicle.

COMMON CAUSES ON HONDA CR-V

• Faulty camshaft position sensor (CMP) itself.
• Damaged, corroded, or loose CMP connector or wiring harness (insulation wear, pin corrosion, water ingress, short to ground or open circuit).
• Oil intrusion or contamination around the CMP or its connector (CMP is often located near the cam gear area and can be exposed to oil leaks).
• Wiring harness routing chafed by belts, heat, or moving engine components.
• Timing-related issues: cam timing misalignment or a stretched/damaged cam chain and/or tensioner that alters the CMP signal (less common but possible in older, high-mileage engines).
• Electrical/system faults: PCM/ECU electrical fault or software glitch (less common on Honda but possible, especially if other CMP-related codes appear).
• Related sensor interactions: issues with the crankshaft position sensor (P0335 and related codes) or VVT solenoid/oil control aspects that affect timing signals can mimic or accompany P0340 symptoms.
• Environmental/drive conditions: extreme temperatures, moisture, or poor grounding can cause intermittent CMP signal problems.

SYMPTOMS

• Check Engine Light (MIL) on or flashing, depending on severity and whether multiple codes are present.
• Rough idle, misfires, or engine running rough at idle or under load.
• Hard starting or no-start conditions.
• Hesitation, reduced power, or poor acceleration.
• Decreased fuel economy.
• Potential stalling or surging in certain driving conditions.
• In some cases, drivability improves after clearing codes or after sensor replacement, but reoccurrence is possible if underlying cause isn’t fixed.

DIAGNOSTIC STEPS (structured approach)

Note: Work safely, with engine cool and ignition OFF when inspecting electrical connectors. If you must crank the engine for testing, follow proper procedures and use insulated tools.

A. Confirm the problem

• Use an OBD-II scanner to confirm code P0340 and check for any related codes (P0341, P0344, P0335, P0336, etc.).
• Review freeze-frame data: engine RPM, throttle position, engine load, coolant temp, and sensor readings at the time of the fault.

B. Visual inspection

• Inspect the CMP sensor and its electrical connector for signs of damage, oil contamination, corrosion, or moisture.
• Check the wiring harness path to the CMP for chafing, loose connections, or damaged insulation (especially near the cam cover, timing area, and belts).
• Look for oil leaks around the camshaft area that might contaminate the CMP sensor or connector.

C. Electrical checks at the CMP connector

• With ignition OFF, disconnect the CMP connector and inspect pins.
• Test for 5V reference at the CMP VREF pin using a multimeter with the ignition ON (engine allowed to be off). If no 5V reference, wiring harness or PCM issue is likely.
• Check for a solid ground at the CMP GND pin.
• Reconnect and verify that the CMP signal wire shows activity when cranking or rotating the engine (use a scan tool to observe CMP signal or use a scope to view the waveform if available).

D. Sensor operation test

• Using the scan tool or oscilloscope, observe CMP signal as you rotate the engine by hand (with spark disabled if possible). You should see a clean, periodic signal corresponding to cam position. A flat line, irregular waveform, or no signal indicates a faulty CMP or wiring issue.
• If available, compare CMP signal to the Crankshaft Position Sensor (CKP) signal; CKP should also be present and relatively stable. Large discrepancies between CKP and CMP timing can indicate timing or sensor issues.

E. Check timing reference (mechanical inspection)

• If CMP and wiring test good, and symptoms persist, assess cam timing. For Honda CR-V, this involves inspection of the cam chain/belt and tensioner and verifying timing marks per the service manual.
• Important: If you suspect timing chain/belt or tensioner issues, this is a major mechanical repair with potential for engine damage if timing is incorrect. Only proceed if you are experienced or in a shop with proper timing tools. In many cases, CMP issues are resolved without disturbing timing components, but a mis-timed engine can be catastrophic.

F. Related systems and secondary checks

• Inspect the crankshaft position sensor (CKP) and its circuit. A faulty CKP can cause cam position misreading or overlapping symptoms with CMP problems.
• Inspect Variable Cam Timing (VCT) solenoid and oil passages if applicable to your engine, as failures can influence timing and CMP readings.
• Check spark plugs and ignition coils for misfire-related symptoms that could confuse interpretation of CMP-related faults.

G. After repairs

• Clear codes and perform a road test to verify the issue is resolved.
• Re-check with a scan tool after a test drive; ensure no new codes appear and that CMP-related data looks normal.

RELATED CODES

• P0340 Camshaft Position Sensor Circuit Malfunction (primary code)
• P0341 Camshaft Position Sensor A Circuit Range/Performance (Bank 1)
• P0344 Camshaft Position Sensor Intermittent
• P0335 Crankshaft Position Sensor A Circuit Malfunction
• P0336 Crankshaft Position Sensor A Circuit Range/Performance
• P0345 Camshaft Position Sensor A Circuit Malfunction Bank 2 (if applicable by model/engine variant)
  Note: The exact bank labeling may vary by engine variant; the core idea is that CMP circuit faults often show with multiple CMP-related codes or CKP/CMP interaction codes.

REPAIR OPTIONS AND COSTS (2025 prices)

Prices vary by region, shop, and engine variant. The following are rough ranges based on typical CR-V repairs and common shop rates (note: all figures are ballpark estimates and should be confirmed locally).

A. Camshaft Position Sensor replacement

• Parts: CMP sensor typically $25–$120 (OEM or aftermarket).
• Labor: 0.5–1.5 hours (depending on access and engine variant).
• Estimated total: $120–$350.
• Notes: If the sensor is easy to reach (some CR-V locations are relatively accessible), this is a straightforward DIY or quick professional job.

B. Wiring harness/ connector repair

• Parts: Insulation, connectors, weatherproof sealant; usually $5–$60 for parts if you replace a connector or add a pigtail.
• Labor: 1–3 hours (based on extent of damage and routing).
• Estimated total: $150–$600.
• Notes: If the harness is chafed or water-damaged, repair may involve splicing and re-sealing.

C. CMP sensor and wiring service combined (recommended if multiple issues found)

• Parts: CMP sensor ($25–$120) plus any connector or harness pieces.
• Labor: 1–2 hours.
• Estimated total: $150–$500.

D. Timing chain/belt, tensioner, or related timing system service

• Parts: Timing chain/belt kit, tensioner, guides, and gaskets; typically $150–$500 for parts (kits vary by engine).
• Labor: 4–8+ hours (significant labor for access and timing work).
• Estimated total: $800–$1,800 or more, depending on engine variant and if主 timing components require replacement.
• Notes: This is a major repair with high cost and risk if timing is not correct. Only pursue if timing issues are confirmed and sensors/ wiring tests are clean.

E. PCM (ECU) replacement or reprogramming

• Parts: PCM or ECU reflash, programming fees.
• Labor: 1–3 hours plus programming.
• Estimated total: $400–$1000+ (parts and programming vary widely).
• Notes: Consider only after thorough diagnostic confirmation that the PCM is at fault, and ideally with validation from a dealer or qualified shop.

F. Miscellaneous/diagnostic fees

• If you take the car to a shop, diagnostic fees may apply (typically $50–$150, sometimes waived with repair).

DIY VS PROFESSIONAL

• DIY-friendly tasks:
  • Inspecting and replacing a CMP sensor when it is easily accessible.
  • Checking obvious wiring harness damage or loose connections.
  • Basic scope or data-logging checks if you have the proper tools.
• Tasks better left to professionals:
  • Diagnosing intermittent CMP signals with proper diagnostic scopes.
  • Verifying 5V reference and ground with a multimeter in a live system.
  • Timing chain/belt, tensioner, and cam/crank timing validation, especially on interference engines like many CR-V variants.
  • Any PCM/ECU reprogramming or replacement and related coding.
• Safety and reliability: If the engine timing is suspected to be off, the risk of internal engine damage is high. In such cases, seek professional service.

PREVENTION

• Regular maintenance: Follow Honda CR-V maintenance schedule for oil changes, filter changes, and timely service of VVT/timing components as recommended for your engine variant.
• Oil management: Keep oil clean and at the proper level; CMP sensors are exposed to engine oil, so a healthy oil system helps prevent sensor contamination or deposits.
• Inspect and protect wiring: During routine maintenance, inspect the CMP wiring harness for chafing or moisture; secure harnesses away from hot surfaces or moving parts.
• Address leaks promptly: If you notice oil leaks around the cam area, repair promptly to minimize CMP contamination risk.
• Use quality parts: When replacing CMP or related sensors, use only quality parts (prefer OEM or proven aftermarket) to reduce the likelihood of premature failure.
• Periodic diagnosis if symptoms recur: If you experience rough idle, misfires, or poor starting, a CMP-related issue may reappear; address early to avoid drivability problems.

Final notes

• This guide uses general automotive diagnostic principles tailored to the 2017–2023 Honda CR-V and the P0340 code. Because the provided data indicates no NHTSA complaints or recalls for this exact combination, the guide relies on standard CMP-related diagnostic practices and typical repair costs. Always refer to the vehicle’s service manual for exact torque specs, connector pinouts, and timing procedures for your specific engine variant (2.4L non-turbo vs. 1.5L turbo, etc.).
• If you’re not comfortable performing electrical tests or timing checks, or if the engine timing may be involved, seek a qualified technician. Correct diagnosis reduces unnecessary part replacement and minimizes the risk of engine damage.