This tutorial will help you to diagnose a P0141 on your 2.0L Honda CR-V. Although this code usually means that you need to replace the rear O2 sensor, sometimes you've got to make sure that its heater element is getting power and Ground.
This tutorial will explain how to make sure the rear O2 sensor is getting power and Ground and how to test the resistance of the heater element itself. All pretty simple tests explained in a step-by-step way.
By the way you don't need any fancy (expensive) diagnostic equipment for these tests, just a multimeter will do.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar El Código P0141 (1997-2001 2.0L Honda CR-V) (at: autotecnico-online.com).
WIRING DIAGRAM: You can find the oxygen sensor circuit wiring diagram here:
- Oxygen Sensor Circuit Diagram (1997 2.0L Honda CR-V).
- Oxygen Sensor Circuit Diagram (1998-2001 2.0L Honda CR-V).
NOTE: If you need to test the front oxygen sensor's heater (trouble code P0135), see the following tutorial:
Circuit Descriptions Of The Downstream Oxygen Sensor
The rear O2 sensor on your Honda CR-V is located after the catalytic converter. Its purpose is to monitor the catalytic converter's effectiveness by checking whether it's filtering out the harmful contaminants produced during the engine's combustion process.
This sensor has four wires: one supplies power to the sensor's heater element, another serves as the heater element's ground, and the remaining two connect to the sensor's internal oxygen-sensing element.
To confirm that the sensor is receiving power and ground, it’s important to know which wires to test.
In the table below, you’ll find a brief description of each of the four wires connected to the rear O2 sensor.
NOTE: One key detail to keep in mind is that the engine wiring harness connector for the O2 sensor has female terminals, while the O2 sensor connector itself has male terminals.
| Downstream Oxygen Sensor -1997 To 2001 | ||
|---|---|---|
| Pin | Wire Color | Description |
| 1 | WHT/RED | O2 Signal |
| 2 | GRN/WHT | O2 Signal |
| 3 | BLK/WHT | Heater Power (+) |
| 4 | BLK/WHT | Heater Ground (-) |
Where To Buy The Oxygen Sensor And Save
The following links will help you to save some bucks on the rear oxygen sensor:
59%
NOTE: If you're not sure if the above downstream O2 sensor fits your particular Nissan Pick Up, don't worry, once you get to the site, they'll make sure the sensor fits, if not, they'll find you the correct one.
TEST 1: Verifying Power And Ground
To get our P0141 diagnostic on the road, we're gonna' make sure that the rear O2 sensor's heater element is getting power and Ground.
To get into specifics: we're gonna' make sure that the black with white stripe (BLK/WHT) wire is feeding the heater element power.
We're also gonna' sure that the black with white stripe (BLK/WHT) wire is feeding the heater element with Ground (yup, both wire are the same colors).
CAUTION: Perform all O2 sensor tests with a completely cold engine. The O2 sensor gets and stays hot for a long time after engine shut down. So if your Honda CR-V's engine has been running for any amount of time, let it cool down completely before you start. Also, if you raise the vehicle to access the O2 sensor, place it on jack stands.
IMPORTANT: The pinout in the illustration above is of the connector on the oxygen sensor itself. To check for power and Ground, you'll test the two indicated wires of the engine wiring harness sensor connector.
OK, this is what you'll need to do:
- 1
Locate the upstream oxygen sensor and disconnect it from its engine wiring harness connector.
- 2
Set your multimeter to Volts DC mode and turn the key ON but don't crank or start the engine (this will power up the O2 sensor's engine wiring harness connector).
- 3
Make sure that the BLK/WHT wire (terminal #3) is feeding battery power.
Connect the red multimeter test lead to the BLK/WHT wire and connect the black multimeter test lead to the battery Ground (-) terminal.
Your multimeter should read 10 to 12 Volts DC. - 4
Make sure that the BLK/WHT wire (terminal #4) is feeding Ground. This Ground is provided by the PCM.
Connect the black multimeter test lead to the BLK/WHT wire and connect the red multimeter test lead to the battery positive (+) terminal.
Your multimeter should read 10 to 12 Volts DC.
Let's take a look at your test results:
CASE 1: Your multimeter registered 10 to 12 Volts DC. This is the correct and expected test results.
Now that you have confirmed that the rear O2 sensors heater element is getting power and Ground. The next step is to check the heaters resistance with a multimeter. For this test go to: TEST 2: Testing The Heater Element's Resistance.
CASE 2: Your multimeter DID NOT register 10 to 12 Volts DC- the most likely cause of this missing power is a blown fuse. Check fuse number in the fuse box and make sure it's not blown.
If the fuse is blown, replace it and repeat this test section.
CASE 3: The heater element is not getting Ground. The most likely cause of this missing Ground is an open in the wiring between the O2 sensor's engine wiring harness connector and its Ground point. Although it's beyond the scope of this tutorial to test for this missing Ground, your next step is to do a continuity test between the O2 sensor Ground wire and Chassis Ground.
