Oxygen Sensor Heater Test -P0135 (1997-2001 2.0L Honda CR-V)

TEST 2: Testing The Heater Element's Resistance

Oxygen Sensor Heater Test -P0135 (1997, 1998, 1999, 2000, 2001 2.0L Honda CR-V)

Now that you have confirmed that the front O2 sensor is getting plenty of power and Ground, in this test section we're going to check that the resistance of the heater element is within specification.

This is a pretty simple test and it's done with your multimeter in Ohms mode. If the front O2 sensor's heater element is not within specification, then you can confidently replace the O2 sensor knowing that it's going to solve P0135 trouble code.

OK, this is what you need to do:

  1. 1

    Locate the O2 sensor's male terminals labeled with the numbers 3 and 4 (in the illustration above).

    These males terminals are on the O2 sensor connector itself (not the engine wiring harness O2 connector).

  2. 2

    With your multimeter in Ohms mode, probe terminals 3 and 4 of the O2 sensor itself.

  3. 3

    If all is OK, you should see about 10 to 40 Ωs on your multimeter.

    If the heater element is fried, your multimeter will show an open (usually indicated by the letters OL) or a number over 10 K Ωs.

Let's take a look at your test results:

CASE 1: The front O2 sensor's heater resistance is within spec. This is the correct and expected test result. Since the front O2 sensor's heater element is within specification, you can now conclude that the O2 sensor itself is not the cause of the P0135 trouble code lighting up your check engine light.

CASE 2: Your multimeter showed an open circuit (OL). This confirms that the upstream O2 sensor's heater element is fried.

To be a bit more specific: you can conclude the front O2 sensor's heater element is defective if you have:

  • Confirmed that the front O2 sensor's heater element is getting power and Ground (TEST 1).
  • In this test, you have confirmed that the heater element's resistance is out of specification.

More 2.0L Honda CR-V Tutorials

There are several more 'how to' tutorials that I've written that are 2.0L Honda CR-V specific, that may be of further help. You can find the ones that are located here, at this site, by going to the Honda 2.0L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

On YouTube, check out my following videos:

Thank You For Your Donation

If this info saved the day, buy me a beer!

If This Info Saved the Day, Buy Me a Beer!

Honda Vehicles:

  • CR-V 2.0L
    • 1997
      1998
      1999
      2000
      2001