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P01552025 Model Year TelemetryMedium Severity

P0155 on 2025 Chevrolet Equinox

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Technical troubleshooting wire for fault code P0155 specifically tailored for the 2025 Chevrolet Equinox. Includes wiring sensor pinouts, freeze frame PID parameters, and step-by-step diagnostic tree.

2025 Engine Control Module (ECM) Specific Calibration
Chevrolet Equinox2025 Equinox
2025 Chevrolet Equinox
SUV1.5L Turbo 4-Cyl (LYX 175HP)
2025 Stats
Vehicle
2025 Equinox
1.5L Turbo 4-Cyl (LYX 175HP)
ECU Subsystem
Automotive OBD-II
SAE Mode $01 & $02
Est. Repair Cost
$120 - $350 (DIY: $45 - $120)
OEM Parts & DIY
Urgency Level
Medium
Drivable (Short)
Switch Equinox Model Year for P0155

Common 2025 Equinox Symptoms

  • Check Engine Light on immediately after cold start
  • Slightly increased cold-start emissions
  • No major driving performance issues once engine reaches full operating temperature

Likely Root Causes on 2025 Equinox

  • Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor
  • Blown O2 heater fuse in under-hood fuse block
  • Corroded or broken heater power/ground wiring
  • Faulty heater driver circuit in the PCM

Step-by-Step Fix Protocol for 2025 Chevrolet Equinox

Step 1: Scan & Record Freeze Frame Data

Connect an OBD-II scanner to the DLC port under the driver dashboard. Record engine RPM, Short Term / Long Term Fuel Trim (STFT/LTFT), and engine coolant temperature at the moment P0155 set.

Step 2: Inspect Wiring Harness & Pin Voltages

Inspect the sensor connector on the 2025 Equinox engine bay. Use a multimeter to verify reference voltage (5.0V / 12.0V) and ground continuity.

Step 3: Component Replacement & PCM Reset

Replace the verified defective component using OEM or equivalent grade parts. Clear DTC P0155 and complete an EPA drive cycle to verify readiness monitors set to READY.

Recommended Parts & Testing Tools

Equipment for Diagnosing 2025 Chevrolet Equinox (P0155)

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Direct-Fit Replacement Part

2025 Chevrolet Equinox OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for 2025 Chevrolet Equinox.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

$29.99 Prime
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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

Compare OEM & Aftermarket Replacement Sensors for 2025 Chevrolet EquinoxVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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