Learning how to test a Corolla oxygen sensor isn’t very hard if you are dealing with the OBDII Diagnostic Trouble Code P0141 for Heated Oxygen Sensor (Bank 1, Sensor 2) Circuit Error. Because the OBDII system in your Toyota is informing you of where the position of the problem 02 sensor is, testing and replacing it is very simple.
Today I’ll be showing you how to test a Corolla oxygen sensor in a 2000 Toyota Corolla with the 1.8 liter 1ZZFE engine. The part number for this oxygen sensor in question is 89465-02030 from Toyota and it’s also available as 89465-12390 or 89465-41010.
As with all of our DIY How To Test Heater Circuit guides, this Toyota oxygen sensor article shows you how to apply the two tests required. You will be measuring for voltage at the wiring harness side of the oxygen sensor, and testing the heater element portion of your 02 sensor.
Where is my Bank 1 Sensor 2 oxygen sensor located?
As our Toyota Corolla is equipped with the 1.8 liter 4 cylinder 1ZZFE engine, we can ignore the Bank 1 designation and simply read Sensor 2. This sensor is the one located after your catalytic converter, meaning you will need to raise your vehicle and secure it to apply our how to.
This oxygen sensor can also be called the rear 02, or the secondary 02 or even the downstream oxygen sensor, but they are all one in the same. To begin our how to test a Corolla oxygen sensor DIY guide, you will need to raise the passenger side of the vehicle and safely secure it. If you are not sure how to safely work on your vehicle, might we suggest checking out our Safety Guidelines or maybe taking your vehicle to an experienced mechanic.
How To Test Corolla 02 Sensor for Power
Once you have your Toyota raised and secured, locate your secondary oxygen sensor. Find and disconnect the 4 pin weatherproof connector and you will be testing the HARNESS side of the connector for both power and ground. You may or may not have to remove the rubber grommet that the wiring harness leads into the cabin with.
Once you have the oxygen sensor unplugged, use your multimeter to probe the HARNESS side of the connector for voltage. The power wire is PIN B and it’s a black wire from the harness side of your Toyota Corolla. Once you have tested this wire for power, check the low reference ground signal wire which is PIN A which is the pink colored wire for ground.
If you don’t have ground at this point, check for continuity between PIN A and the sensor ground wire of your 1ZZFE ECU.
How To Check a Toyota Corolla oxygen sensor
The last part of our DIY How to on checking your Toyota Corolla 02 sensor is testing the sensor itself. You will be testing the SENSOR side of the harness connector for the last test to fix your P0141 OBDII trouble code.
Using your multimeter in Ohms mode you want to check for the resistance value between the two terminals you just tested. This will tell you if your Corolla downstream oxygen sensor has gone bad and needs repair, or the issue with your P0141 check engine code lies elsewhere.
Measure the resistance between PIN B and PIN A and if your oxygen sensor returns a value between 11 and 17 Ω, then the oxygen sensor is still good. If it shows an open circuit or an unnaturally high resistance value, it’s time for a replacement.
Use the part number guide above to find the Toyota Corolla oxygen sensor you need at the right price, and if you have any questions about our how to test a Corolla oxygen sensor DIY Guide, please leave them for us below!
Thank you so much for a tutorial that I could understand.
You are welcome Tom! Thanks for commenting!