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P0155 on Chevrolet Equinox

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Chevrolet Equinox (2020–2026, 1.5L Turbo 4-Cyl (LYX 175HP)).

Verified OEM Telemetry & Field Repair Tree
Chevrolet Equinox2020–2026
Chevrolet Equinox
SUV1.5L Turbo 4-Cyl (LYX 175HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Equinox SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$120 - $350 (DIY: $45 - $120)
Parts & Labor DIY
Check P0155 On Another Chevrolet Model:
Diagnose P0155 on Specific Equinox Model Year:

1. Symptoms of P0155 on Chevrolet Equinox

When the Engine Control Module (ECM/PCM) on your Chevrolet Equinox (1.5L Turbo 4-Cyl (LYX 175HP)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Chevrolet Equinox (1.5L Turbo 4-Cyl (LYX 175HP))
Slightly increased cold-start emissions on Chevrolet Equinox (1.5L Turbo 4-Cyl (LYX 175HP))
No major driving performance issues once engine reaches full operating temperature on Chevrolet Equinox (1.5L Turbo 4-Cyl (LYX 175HP))
Chevrolet Equinox OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell above brake arm. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Chevrolet Equinox

Historical warranty claims and technical repair bulletins for Chevrolet Equinox point to the following failure distribution:

55%
Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor (Chevrolet OEM Part)
25%
Blown O2 heater fuse in under-hood fuse block (Chevrolet OEM Part)
12%
Corroded or broken heater power/ground wiring (Chevrolet OEM Part)
8%
Faulty heater driver circuit in the PCM (Chevrolet OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Chevrolet Equinox.

3. Step-by-Step DIY Repair Guide for Chevrolet Equinox

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Chevrolet Equinox equipped with 1.5L Turbo 4-Cyl (LYX 175HP).

Required Tool: Fuse Puller, Test Light
02
Test Heater Resistance on Bank 2 Sensor 1

Unplug the sensor connector and measure resistance between the two heater pins. An open circuit (infinite ohms / OL) confirms a dead internal heater. on the Chevrolet Equinox equipped with 1.5L Turbo 4-Cyl (LYX 175HP).

Required Tool: Digital Multimeter
03
Replace Bank 2 Upstream O2 Sensor

Remove faulty sensor and install a new OEM oxygen sensor with built-in heater. on the Chevrolet Equinox equipped with 1.5L Turbo 4-Cyl (LYX 175HP).

Required Tool: 22mm O2 Sensor Socket, Ratchet
04
Clear Codes and Perform Cold Start Verification

Clear DTCs and allow engine to cool down, then restart to confirm P0155 does not return. on the Chevrolet Equinox equipped with 1.5L Turbo 4-Cyl (LYX 175HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Chevrolet Equinox (P0155)

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Direct-Fit Replacement Part

Chevrolet Equinox OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for 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.

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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.

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Other Common Fault Codes on Chevrolet Equinox

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Chevrolet Equinox:

4. Chevrolet Equinox P0155 FAQs

What causes code P0155 to trigger on a Chevrolet Equinox?

On the Chevrolet Equinox (1.5L Turbo 4-Cyl (LYX 175HP)), P0155 is most frequently caused by Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor or Blown O2 heater fuse in under-hood fuse block.

Where is the OBD-II port located on my Chevrolet Equinox?

On the Chevrolet Equinox, the 16-pin DLC diagnostic connector is located Driver footwell above brake arm. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Chevrolet Equinox with code P0155?

Yes. The sensor will take longer to warm up, causing brief open-loop fuel delay on cold starts. Given that P0155 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.