Understand & Fix P0058: HO2S Heater Control Circuit High (Bank 2, Sensor 2) with iCarsoft CR Pro S

If your vehicle’s check engine light illuminates, you notice poor fuel economy, or it fails an emissions test, a diagnostic scan will likely return P0058. This OBD-II code stands for "HO2S Heater Control Circuit High (Bank 2, Sensor 2)"—a critical fault targeting the heater circuit of the second oxygen (O2) sensor on the second cylinder bank. Oxygen sensors monitor exhaust gas oxygen levels to optimize fuel injection; the heater element warms the sensor quickly (especially on cold starts) for accurate readings. A "high circuit" error means the Engine Control Module (ECM) detects excessive voltage in the heater circuit, preventing the sensor from reaching operating temperature.

Basic scanners might only flag an "O2 sensor error" but can’t test heater circuit voltage, verify sensor responsiveness, or check wiring integrity—leaving you guessing between a faulty sensor, damaged wiring, or a failing ECM. The iCarsoft CR Pro S, with its OE-level engine diagnostics, live voltage tracking, and bi-directional testing, solves this. Below, we break down P0058, its causes, symptoms, step-by-step resolution, and 8 FAQs to answer common troubleshooting questions.

What Is P0058?

P0058 focuses on the heater control circuit of the Bank 2, Sensor 2 oxygen sensor (HO2S). Bank 2 refers to the cylinder bank opposite the number 1 cylinder, and Sensor 2 is the "downstream" sensor (located after the catalytic converter). The sensor’s heater circuit consists of a heating element, wiring harness, connectors, and an ECM-driven switch. The ECM supplies 12V to the heater to warm the sensor to 600–800°F (315–425°C) for optimal performance. A "high circuit" error indicates the ECM detects voltage above the normal range (often >12.5V) or no current flow, signaling a short, open, or unresponsive component.

Key Symptoms of P0058

• Illuminated Check Engine Light: The primary warning sign, often paired with codes like P0054 (Bank 2, Sensor 1 heater circuit) or P0420 (catalytic converter efficiency below threshold).
• Poor Fuel Economy: A cold or unresponsive O2 sensor sends incorrect data, leading to rich fuel mixture and increased consumption.
• Rough Idle or Hesitation: Incorrect fuel injection timing disrupts combustion at low speeds.
• Emissions Test Failure: The downstream O2 sensor’s inability to monitor catalytic converter performance triggers emissions non-compliance.
• Cold Start Issues: The sensor takes longer to warm up, causing delayed fuel optimization.
• Catalytic Converter Damage: Prolonged rich fuel mixture can overheat and damage the catalytic converter.

Common Causes of P0058

Why iCarsoft CR Pro S Excels at Diagnosing P0058

The CR Pro S outperforms basic tools with features tailored to O2 sensor and heater circuit diagnostics:

Step-by-Step: Diagnose P0058 with iCarsoft CR Pro S

1. Confirm P0058 & Gather Data

   Plug the CR Pro S into your vehicle’s OBD-II port, power on the tool, and select AutoVIN Identify to auto-detect make, model, and cylinder bank configuration.
   Navigate to Engine > Fault Codes > Read Codes to confirm P0058. Tap Code Details for model-specific insights (e.g., "Honda Civic: Bank 2, Sensor 2 HO2S Heater Circuit High; Voltage: 13.2V, Expected: 12V; Check Sensor or Wiring").

2. Analyze Live O2 Sensor Data

   Go to Engine > Live Data > Oxygen Sensors and monitor three key metrics:
   1. Bank 2, Sensor 2 Heater Voltage: Fluctuates 0V (deactivated)–12V (activated) per ECM commands. Fixed >12.5V = P0058.
   2. Sensor Temperature: Should reach 600–800°F (315–425°C) within 2–3 minutes of cold start—failure to heat = heater circuit issues.
   3. Sensor Voltage Output: Cold sensor shows fixed/erratic voltage (normal warm output: 0.1–0.9V fluctuating rapidly).

3. Test the O2 Sensor & Heater Circuit

   1. Use Bi-Directional Control > Engine > O2 Sensor Heater Test: Send activation commands to Bank 2, Sensor 2 heater. Check voltage drops to 12V and temperature rises. No change = faulty sensor.
   2. Locate the sensor: Use the CR Pro S’s Component Location tool (downstream of catalytic converter on Bank 2).
   3. Inspect & Test: Check for damage, oil contamination, or water intrusion. Use Resistance Test on heater element (match OEM specs, e.g., 10–40 ohms—open/infinite = faulty sensor).

4. Inspect Wiring, Connectors, & Fuses

   1. Wiring Check: Use Continuity Test on heater circuit wiring for breaks/shorts. Look for damage near heat sources or moving parts.
   2. Connector Check: Clean corroded connectors with electrical contact cleaner. Use Voltage Drop Test to check connection resistance.
   3. Fuse/Relay Check: Navigate to Vehicle > Fuse Box Diagram (via CR Pro S) to find O2 sensor-related fuses/relays. Test continuity with multimeter.

5. Repair & Clear the Code

   - Replace Bank 2, Sensor 2 O2 sensor if faulty. Repair damaged wiring or replace blown fuses/relays.
   - Use the CR Pro S to Clear Codes and reset ECM adaptive learning (under Special Functions) to sync with the new sensor.
   - Test drive 50–100 miles. Use I/M Readiness Test to verify emissions compliance.

FAQs: P0058 Troubleshooting