Honda Accord P0141 Code Even With New O2 Sensor | Heater Circuit Diagnosis (K24)

If your Honda Accord keeps throwing a P0141 code even after replacing the downstream O2 sensor, this video shows the diagnostic process that narrowed the problem down.

Vehicle:
2005 Honda Accord
K24 engine

Code:
P0141 – Bank 1 Sensor 2 O2 Heater Circuit

In this case the downstream O2 sensor was replaced with a new Denso sensor, but the code returned within about 10 seconds of startup. That fast return indicates the ECU is performing an electrical integrity test of the heater circuit rather than waiting for the sensor to warm up.

Measurements taken at the B1S2 connector:

Heater power wire: ~12V present
Heater control wire: ~0.5V floating
Sensor signal wires: ~0V

Applying a temporary external ground to the heater control wire caused the heater element to immediately begin heating, confirming the heater element itself and the power supply circuit were functional.

However the ECU still set P0141.

This indicates the ECU monitors current flow through its internal heater driver circuit and will not accept an externally grounded heater circuit.

At this stage the remaining likely causes were narrowed down to:

• Open or high-resistance heater control wire
• Connector or pin issue between the ECU and sensor
• Failed ECU heater driver

This video walks through the full diagnostic process and measurements.

Helpful related Honda repair videos:

Honda downstream O2 sensor replacement
https://www.youtube.com/results?search_query=honda+accord+downstream+o2+sensor+replacement

Honda P0141 diagnostic discussions
https://www.youtube.com/results?search_query=honda+p0141+diagnosis

Honda K24 knock sensor replacement
https://youtu.be/KSOSrb-2ykI

More DIY diagnostics and repair videos:
https://www.youtube.com/@YourChannelName

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Видео Honda Accord P0141 Code Even With New O2 Sensor | Heater Circuit Diagnosis (K24) канала Eric Mcginn