Explains the O2 Sensor Heater Wiring Test using cost effective procedures. Good for the Professional Tech or DIY . www.autodiagnos... www.autodiagnos... www.autodiagnos... www.autodiagnos...
Very professional and technical excellence. The biggest headache on modern combustion engine vehicles near or exceeding 100k miles is the dreaded "check engine light". I didn't even know there was a heater inside these O2 sensors. Just a pain-in-the-ass to remove if not had anti-seize grease prior. That's just one issue now there's more headache with a heater issue. i.e. PO131 OBD2 code. Best after purchasing any vehicle with 100k miles is to replace all of the O2 sensors for any unforeseen breakdowns ahead.
great, useful video. I am hunting P2237 and P2238 for bank 1 sensor 1 on my 2008 Toyota 4RUNNER V6.. Bank 1 is a passenger side. I replace both upstream AF sensors a year ago for unrelated OBD II code with OEM Denso, I doubt the code I experiencing now are the faulty sensor itself. Sometimes these codes are going away and comeback several weeks or days after. Need to pinpoint.
@@ADPTraining what is reflashing? You mean with ECM? I did not do anything with it, not even disconnect the battery.. Can you please elaborate? Thank you for taking your time to read and reply.
Instead of using a dome lamp to test the heater power and ground, could you use an old fashion 12 volt probe tester? The one with a wire that clamps to ground and a small bulb that lights when the probe is touched to 12 volts.
Hi. I have four wire sensor. Which i understand the two same color which are white are the heater. But my question is, to do this test, how would i know which one is the heater ground? Thanks in advance.
Doesn't really matter, it's a good question, but it's a heater, so polarity doesn't matter. However, beware because the other two wires, one is black, which could be signal, and gray which could be ground. For some reason, these older aftermarket O2 sensors the black was signal and the gray was ground. Go figure... Good luck, Mandy. autodiagnosticsandpublishing.com/
There is no relay. Positive comes from the battery and negative from the ECU (computer). The heating element is constantly on when the engine is running
Thank you, this video is amazing! I would like to ask, I have a motorcycle engine with a failed heater on the downstream 4 wire sensor, but I can't find an original used or oem part for replacement (I cant afford 450USD right now) but I see that Bosch once made a universal 4 wire O2 sensor ... is it reasonable that if I find a cheap O2 used sensor from a similar size engine from some other manufacturer - that I would be able to use that sensor if rewired correctly - are they all basically operating at the same output voltages?
Absolutely, yes and it doesn't even have to be the same size engine. The O2 sensor senses Oxygen independently of engine size. A new universal O2 sensor is probable less than $100. Also, make sure your bike doesn't have an AFR or air fuel ratio sensor. They look the same, but are different. Good luck.
@@ADPTraining The bike is a 2008 Varadero 125, it has the smaller 12mm thread for the O2 sensors, so was thinking to get a reducer and use an 18mm O2 sensor but so far have been using the bike with the sensor missing - lots of secondary combustion on heavy de-acceleration, not sure if that's from the missing sensor or the less restricted aftermarket down-pipes (installed as a result of destroying the original during an engine swap) in any case, I really appreciate you putting these videos together, very well explained on the theory and the troubleshooting. 🙏Thank you!
Before teaching people try to teach yourself because you are teaching people wrongly, A high voltage signal indicates an imbalance in the air-fuel ratio - a low oxygen concentration in the exhaust gas (and an excess of fuel running through the engine) that means it is a rich condition not the lean condition, thanks
Greetings, I have Ford Focus 1.4 16V from 2003. My problem is that I only have error code P0420 and find out that my heater circle on both upstream and downstream are not working. There is 12 volts on heater element but the problem is ground which controls PCM. Is there any way to bypass PCM ground?
I think that problem is in PCM because there is 12 v on pcm ground connector. But when I connect light bulb (12v 21w) and start my car bulb is not flashing. When I connect amp meter in series with heating element of O2 sensor by turning car key there is "spike" of 0.86 Amps and then lowers to 0.02 Amps. When car is running ampermeter shows constantly 0.02 Amps. I think that transistor or somethimg controling ground in PCM is burned. I was thinking bypassing PCM ground with chip 555 and some power transistor.
Great video, I done a live test on my oxygen sensor, it comes on for like 30 secs then no response, I fitted a new sensor. Can this test find the fault. AUDI 1.8t engine, AGU, it’s been swapped into a mk1 golf/rabbit
Searching for the options to remove P0446, I replaced 2 oxygen sensors (along with many others). 2001 Saturn SL2, 130K. After 10 mi got P0038. I thought defective downstream O2 sensor, but maybe it is just bcs the heater doesn't work in that car. But w/original sensor there was no code P0038. Can you clean those sensors w/some carb cleaner? So it will be more time to find a proper sensor, if it is not that broken heater of course. I would appreciate any opinion on this problem. Thank you for the informative film.
Code P0446, otherwise known as Evaporative Emission Control System (EVAP) Vent Control Circuit Malfunction, indicates that your car's computer has detected (or believes it has detected) a problem with the function of the EVAP system. This is a circuitry code. This has nothing to do with the O2 sensors.
Ok. One question. The AFR heater (lsu 4.9 afr sensor) resistance or/and current value differs from light bulb resist/current. Will ECU will see that difference? If yes it will not close circuit and bulb will not flash...
what if the sensor's ground is computer controlled and it is short to ground. ??? p0141 . Ground is on all times , 12v wire is on all the time with Ignition on . code p0141 registered. how to find short to ground of the sensor's ground.? thank you 🙏
Well that's exactly how it works. Heater Gnd can't no on all the time. So, yes there is a short to ground. Sensor ground is on all the time, but the heater is either power controlled, ground controlled or PWM controlled on newer AFR sensors. www.autodiagnosticsandpublishing.com/
Way too complicated... Just measure the amp at the fuse box and see what the current draw is. 5 minutes job. If you don't have an amp meter remove the sensor from the exhaust. Start the engine and hold the sensor with one hand. If you smell burning flesh, the heater works perfectly, if not replace the damn thing.
Hundreds of sensors get replaced needlessly. A loss for the consumer, shop owner. Thanks for posting. See our training downloads here. autodiagnosticsandpublishing.com/
rig up some random headlights ?...that i just have sitting around to just do the test? this is way too complicated. testing procedure setup is too time consuming. how many people have random spare headlights sitting around their garage. maybe we can go to junkyard buy some for $30 which is the same as o2 sensor.
ADPTraining The answer is a little long but because you have the courtesy to reply my question I will explain, my daughter hit an street bump and the O2 conector disapear leaving the 4 wires rubbing the street, the car harnes conector was damaged, so I decide to connect the wires with but splicers and found the two heater wires are not color coded as the signal are, and because after clear the MIL, it came back with some heater low voltage code the only I can think it may be the problem, but I guess is not, Ihave to keep investigating, thanks so much and any help will be super appreciated
Ok, the CEL not working is key here. Look for missing power or ground, but really look. That's the only explanation for CEL not working. Then of course if CEL not working, means no power/ground, no injectors, no spark, etc. Check and please repost back here, Mandy.
