P0155 Code: Honda CR-V (2017-2023) - Causes, Symptoms & Fixes

COMPREHENSIVE DIAGNOSTIC GUIDE: P0155 ON 2017-2023 HONDA CR-V

Data note and recalls

• Real NHTSA data for this make/model/year/issue: No owner complaints found.
• Official recalls: No recalls found in NHTSA database.
• No recalls found in NHTSA database (as required by data you provided).
• Transparency about data limits: There are no documented complaints or recalls in the supplied data for P0155 on the 2017-2023 Honda CR-V. This guide relies on general OBD-II knowledge and typical Honda CR-V behavior for this code.

CODE MEANING AND SEVERITY

• P0155 = O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1).
• What it means:
  • The heater element inside the O2 sensor for Bank 2 Sensor 1 is not heating properly. The heater helps the sensor reach its operating temperature quickly, so readings are accurate early in a cold start and during engine operation.
  • With a faulty heater, the sensor may stay cold longer, producing slow or inaccurate readings. The engine control module (ECM/PCM) may not get reliable oxygen data, potentially affecting fuel trims and emissions.
• Severity:
  • Moderate. In many cases the car will still run, but fuel economy and emissions can be affected, especially until the sensor warms up. A MIL (check engine light) is likely, and you may fail an emissions test depending on test timing and vehicle conditions.
  • If the heater circuit is truly open or shorted, it can trigger the MIL and set P0155. If the sensor heater is not heated, other O2 sensor readings (and downstream catalyst efficiency) can be impacted.

COMMON CAUSES ON HONDA CR-V

• Faulty Bank 2 Sensor 1 O2 sensor itself (heater element has failed).
• Damaged or corroded wiring to Bank 2 Sensor 1 O2 sensor (insulation wear, shorts to ground, or broken pins).
• Poor or loose electrical connectors (wet or corroded connectors, unplugged harness).
• Blown fuse or faulty relay that powers the O2 sensor heater circuit.
• Wiring harness ground or supply issues (bad ground, high resistance, or voltage drop).
• Exhaust leaks upstream or downstream of the sensor (misleading readings can accompany heater faults in some cases).
• Contamination or sensor age (older sensors can fail to heat properly even if the heater coil isn’t completely open).
• In rare cases, a failing PCM/ECU can misinterpret or fail to energize the heater circuit (less common).

SYMPTOMS

• Check Engine Light (MIL) illuminated with P0155 stored.
• Increased fuel economy variability or lean/rich conditions as the sensor stays too cold to provide accurate data.
• Rough idle or hesitation during cold-start while the sensor heats up (short duration, often not dramatic).
• Possible failed emissions test or elevated tailpipe emissions until sensor warms.
• No obvious drive-ability loss in some cases; other times you may notice engine running slightly differently as trims adjust.
• If there are additional O2 sensor codes (e.g., P0135, P0150–P0153), you may see multiple trouble codes related to oxygen sensors or heater circuits.

DIAGNOSTIC STEPS

Preparation:

• Obtain a current OBD-II scan of the vehicle and note freeze-frame data (engine temp, RPM, fuel trims, catalyst temperature if available).
• Confirm the exact sensor location: Bank 2 Sensor 1 is the oxygen sensor on Bank 2 (the opposite bank from Bank 1) and the first sensor in that bank. On inline-4 Hondas, there may be references to Bank 2 Sensor 1 even though some systems use Bank 1 terminology; follow the dealer/repair manual for your exact model/year if in doubt.

Step-by-step:

Confirm the code and check for related codes.

• Read all codes. If P0155 is the only code, focus on O2 sensor heater circuit for B2S1. If other O2 sensor codes exist, address them in sequence.

Visual inspection of wiring and connectors.

• Inspect the Bank 2 Sensor 1 harness and connector for damage, corrosion, or moisture.
• Check for pin corrosion, bent pins, or loose connections. Re-seat and clean as needed.
• Look for obvious wiring damage (chafed harness, heat damage near the exhaust, or grounding issues).

Check fuses and power supply.

• Locate the fuse/relay that powers the O2 sensor heater circuit and verify it is intact.
• Check for voltage supply at the sensor connector when the ignition is on and the engine is at operating temperature; confirm ground continuity.

Test the O2 sensor heater circuit resistance and operation.

• With the sensor unplugged, measure the heater circuit resistance across the heater pins. Typical heater resistance is several ohms (not open). Very high (open circuit) or very low/shorted values indicate a failed heater or internal short.
• If you can safely energize the heater circuit with a known-good supply (some scan tools can command sensor heaters on/off), observe whether the heater draws current as expected. If the heater does not energize or current draw is absent, suspect wiring, fuse/relay, or sensor itself.
• Compare measured resistance to service specifications for the Honda CR-V sensor (your repair manual or a factory service data source will give the spec). If the sensor is out of spec, replace it.

Check for exhaust-related issues or sensor placement.

• Ensure there are no exhaust leaks near the sensor that could cause readings to be atypical.
• Verify the sensor is properly installed and not cross-threaded or damaged.

Consider sensor replacement or service options.

• If the harness and fuses check out, and heater resistance is out of spec, plan for sensor replacement.
• If a replacement sensor is installed, re-scan to confirm P0155 clears and overnight or after a drive cycle the code remains cleared. If the code returns, re-check wiring and ground paths.

Optional dealer/independent shop step.

• If the code persists after replacing the sensor and verifying wiring, suspect ECU/PCM or an intermittent wiring fault that requires more advanced diagnostics (scope traces, heater control circuit logic). This step is more advanced and often requires professional equipment.

Notes on testing approach:

• Do not rely on oxygen sensor readings alone to diagnose the heater circuit. The heater can fail while the sensor still appears to function intermittently, so heater-specific tests are needed.
• After any repair, clear codes and perform a road test to ensure the code does not return under normal driving and that the sensor reaches operating temperature promptly.

RELATED CODES

• Other O2 sensor or heater-related codes that can appear with P0155 or in the same system include:
  • P0135 (O2 Sensor Heater Circuit Malfunction – typically Bank 1 Sensor 1)
  • P013x and P015x family codes related to O2 sensor heater circuits (various banks/sensors)
  • P0141, P0150–P0153 (O2 sensor circuit issues not specific to heater, but often appear when the sensor or harness has a fault)
• Note: The above codes are commonly seen in conjunction with oxygen sensor issues in many vehicles, but exact bank/sensor mapping can vary by model/year. Use your scanner’s definitions for the precise bank and sensor reference.

REPAIR OPTIONS AND COSTS (2025 PRICES)

Prices are approximate and vary by region, shop, sensor type (OEM vs aftermarket), and labor rates.

• O2 sensor replacement (Bank 2 Sensor 1):

  • Parts: Aftermarket sensor typically $25–$120; Honda OEM sensor often $120–$250.
  • Labor: About 0.5–1.0 hour (some cars may require more); shop rates commonly $90–$150 per hour.
  • Total typical cost: $150–$350 (parts and labor for one sensor). If the sensor is difficult to reach or you replace both sensors as a precaution, costs will be higher.

• Wiring harness repair or connector replacement (if wiring is damaged):

  • Parts: Connectors, weather sealing, or repair harness segments may be $5–$30 plus labor.
  • Labor: 0.5–2.0 hours depending on access and extent of repair.
  • Total typical cost: $100–$300 if the issue is limited to harness repair and reseating connectors.

• Fuses/relays (simple electrical fix):

  • Parts: Small fuse or relay, usually $5–$20.
  • Labor: Minimal if diagnosed; DIY-friendly.

• ECU/PCM issue (rare):

  • Parts: Reprogramming or replacement may be required.
  • Labor: 1–3 hours plus diagnostic time.
  • Total typical cost: $300–$1,000+ depending on parts and shop.

• Comprehensive diagnosis (if using a shop):

  • Flat diagnostic fee or hourly rate plus time spent. Expect $80–$150 per hour in many areas.

Notes:

• If multiple O2 sensor codes are present, consider replacing the sensor(s) in the affected bank first, then recheck before probing the ECU.
• Always clear codes after repairs and perform a test drive to confirm that the issue is resolved.

DIY vs PROFESSIONAL

• DIY considerations:
  • Replacing an oxygen sensor is a common, doable job for a handy DIYer with basic hand tools, including an oxygen sensor socket and anti-seize compound.
  • Pros: Lower cost, learning experience, quick turn-around.
  • Cons: Working near hot exhaust components; improper torque or sealing can cause exhaust leaks; misdiagnosis may lead to unnecessary replacements.
  • Tips: Use penetrating oil on exhaust threads, avoid cross-threading, apply a light amount of anti-seize on the sensor threads (per manufacturer recommendations), and disconnect the battery if required by your vehicle’s service procedure.
• Professional considerations:
  • Pros: Accurate diagnosis, safe handling of electrical and exhaust components, proper torque and sealant application, and proper emissions handling.
  • Cons: Higher upfront cost.
• When to go pro:
  • If you’re not confident testing sensor heater circuits, wiring harness continuity, or interpreting electrical pull/ground data.
  • If the code returns after a sensor replacement.
  • If you suspect ECU/PCM issues or need advanced scope testing.

PREVENTION

• Replace O2 sensors at recommended intervals. While many sensors last 60k–100k miles, bank-specific sensors can fail earlier due to heat and contaminants.
• Maintain exhaust system integrity. Fix exhaust leaks promptly to avoid inaccurate sensor readings and catalytic converter stress.
• Keep air intake and fuel system clean. Replace air filters on schedule, use quality fuel, and address misfires promptly to prevent sensor contamination or inaccurate data.
• Avoid aggressive short trips. Short trips keep the engine from reaching stable operating temperature, which can affect O2 sensor readings and catalyst heating dynamics.
• Inspect and maintain wiring harnesses near the exhaust, as heat and vibration can cause insulation wear over time.
• If you have recurring emissions concerns or failing smoke/emissions tests, consider a professional diagnostic to ensure the heater circuit is properly energized and that the sensor data is being used correctly by the PCM.

Bottom line

• P0155 on a 2017–2023 Honda CR-V indicates a problem with the Bank 2 Sensor 1 O2 sensor heater circuit. In many cases this points to a faulty sensor or its wiring, a blown fuse/relay, or a connection issue. Begin with a careful electrical inspection and sensor test; replacing the sensor is a common and effective remedy. If the issue persists after sensor replacement and wiring checks, deeper electrical or ECU diagnostics may be needed.

Data transparency reminder

• This guide reflects the data you provided (no complaints, no recalls) and uses general automotive knowledge for diagnostic steps, common causes, and typical costs. If new recalls or complaints appear in NHTSA or dealer data, the guidance should be reviewed accordingly.