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P0155 on Kia: Symptoms, Causes & Fix

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Official technical diagnostic wire for fault code P0155 specifically affecting Kia vehicles (K5, Telluride, Sportage, Sorento, EV6).

Sensor Voltage Ref
0.1V – 5.0V Ref
Kia Factory Standard
CAN Bus Speed
500 kbps CAN-FD
ISO 15765-4 Diagnostic Bus
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$120 - $350 (DIY: $45 - $120)
Parts & Labor DIY
Model-Specific Diagnostic Wires

Select Your Kia Model for P0155:

6 Models Available

1. Common Symptoms on Kia Vehicles

When Kia Engine Control Modules (ECM) trigger fault code P0155, drivers typically report:

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

2. Root Causes on Kia Engines

Historical diagnostic claims across Kia engines point to the following failure distribution:

55%
Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor (Kia OEM Part)
25%
Blown O2 heater fuse in under-hood fuse block (Kia OEM Part)
12%
Corroded or broken heater power/ground wiring (Kia OEM Part)
8%
Faulty heater driver circuit in the PCM (Kia OEM Part)

3. Step-by-Step Fix Protocol for Kia

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on Kia engines.

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 Kia engines.

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 Kia engines.

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 Kia engines.

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

Equipment for Diagnosing Kia (P0155)

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Direct-Fit Replacement Part

Kia OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Kia.

$45 – $95 Prime
Check Fitment on Amazon
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 KiaVerified direct-fit pricing from Denso, Bosch, Motorcraft, and ACDelco on Amazon.
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4. Kia P0155 Frequently Asked Questions

What does code P0155 mean on a Kia?

On Kia vehicles, P0155 indicates that the Engine Control Module (ECM) detected o2 sensor heater circuit malfunction (bank 2 sensor 1). This typically points to Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor or Blown O2 heater fuse in under-hood fuse block.

Can I continue driving my Kia with code P0155?

Yes. The sensor will take longer to warm up, causing brief open-loop fuel delay on cold starts. Because this code carries a Medium severity rating on Kia powertrains, we recommend scanning live data values promptly to prevent secondary damage.

How much does it cost to fix code P0155 on a Kia?

Estimated DIY parts cost ranges from $120 - $350 (DIY: $45 - $120), while professional shop repairs at an authorized Kia dealership or independent specialist typically range from $180 to $380 including diagnostic labor.