How To Test O2 Sensor Heater? 3 Best Ways!

Have you ever worried about how to test o2 sensor heater? Begin by physically analyzing the cables that connect the O2 Sensor to the rest of the system. Check whether the wires are appropriately channeled out from the emission parts and therefore are not broken. After that, start the engine and just let it go for 5 – 6 minutes until it just warms up. 

Hook up a backprobe towards the signal line of the oxygen sensor. While utilizing a backprobe, be cautious because the silicone connections are typically fragile and shatter. Attach the backprobe towards the positive lead first from the voltmeter. Examine the voltmeter value after turning the car back on. 

how to test o2 sensor heater

 Ensure the car is heated correctly up if the reading lingers above 0.8 volts. Whereas if the vehicle is heated and the 02 Sensor reading doesn’t alter, the 02 Sensor is malfunctioning, and thus the test should be stopped. Keep reading to discover more.


What Is A O2 Sensor?

Usually, one oxygen sensor is fixed across every modern automobile and most vehicles made after 1990. Its purpose is to assist the engine in maintaining a specific atmosphere proportion that helps balance horsepower, fuel efficiency, and pollutants. The O2 sensor measures how much oxygen is in the emissions relative to how much is in the air. It sends this data towards the engine computer, which changes the air/fuel intake accordingly. Read more about what is an o2 sensor.


Ways To Test O2 Sensor Heater

Oxygen sensors can be tested in various ways, which could be performed without special equipment. The most efficient testing is performed on a sensor mounted on such an engine control unit under typical different operating conditions, while specific tests may be performed off-vehicle. The following tools can test oxygen sensors and help you learn how to test o2 sensor heater. 


#1. Test by multimeter 

The most superficial testing using a multimeter is checking if the heating coils onto an oxygen sensor are damaged. Set the multimeter on resistance’ setting to examine the heat source of the oxygen sensor. Attach the testing lines to the connectors or cables on the heater’s supply and ground connectors. According to the multimeter reading, the resistance of many of these warmers is between 10 – 20 ohms.

Make very sure the vent on the engine is fantastic. Sure, heaters would not go on if the engine emission pipes were heated. Turn on the multimeter and select the ‘DC voltage’ option. Set the wires to the cables or connections of the heater. The  Back-probes seem to be the most effective instrument in this situation. 

When you don’t have accessibility to back-probes, detaching the oxygen sensor out of its harnesses and attaching the multimeter to a connection may be the simplest way of connecting the multimeter to transmission lines. See the engine repair handbook to discover how much you can and could do there. Start the engine. Using the multimeter, check the total voltage; it should be around 13 and 15 volts.


#2. Test by the clamp meter

Clamp-meters simply make examining the oxygen sensor considerably quicker and easier to test. Everything you must do is complete the following things. Ensure the exhaust pipe on the engine is cool, turn on the clamp-meter and set it to DC amperage.’ Connect the o2 heater power wires with the clamp.  Make sure the hands or instrument isn’t resting on the engine or exhaust and start the engine.  Keep an eye on the current value between 0.26 and 2.0 amps. Compared to a traditional multimeter, this clamp-meter has the following benefits: it is faster, better comprehensive, and far less intrusive since it does not impede the engine’s proper functioning.


#3. Test by oscilloscope

Oscilloscopes are beneficial instruments that provide much more information than multimeters, and they can be challenging to be used with o2. Because automobiles may well not have a grounding with the mains power in a yard or workshop, it’s typically better to use a rechargeable batteries oscilloscope and one with separated ports. Any vehicle that is ‘hovering’ up or down the voltage of an oscilloscope’s power supply might release a large current at high voltage, destroying the vehicle circuitry or the oscilloscope. While using an oscilloscope to test o2, the next challenge is attaching the oscilloscope to an o2 sensor circuit(s), which is best achieved via back-probes. 

To utilize an oscilloscope on an o2 sensor, you’ll need to do the following. Ensure the oscilloscope terminals are correctly separated from mains electricity in the carport or workshop. Attach the oscilloscope probing to the o2 sensor cell lines. Make sure the cables won’t get in the way of the engine’s mechanical parts. 

Whereas the engine is operating, monitor the o2 sensor readings over time. Whereas the engine heats up, o2 sensor outputs should be lower, then climb to an overall average corresponding to a ‘normal’ combination. Sensor outputs from pre-catalytic converter must typically vary swiftly between ‘full’ and ‘thin.’ Overall results of post-catalytic converters should be far more consistent, hovering all-around ‘balancing’ level. Turn the power off. I am waiting till the engine is completely cold before starting it. Disconnect the oscilloscope needles from the oscilloscope.


It’s A Wrap!

We are happy to know that you have learned how to test o2 sensor heater. The ways mentioned above are best to test the o2 sensor, but you need to read the procedure to test the sensor thoroughly. Thank you, friends. For staying with us.

Click on these links to read related articles; know how to make car heater warm up faster and what causes car heater to blow cold air

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