Engine Coolant Temperature Sensor P0117 / P0118 | How to Test and Replace

now today we're looking at an engine coolant temperature sensor now these are very important just because if you do have a trouble code for this sensor you may have trouble starting your vehicle may be improper idling so it's always a good idea to test this sensor before you run out and see really what's going on so that being said let's jump over to the vehicle we'll remove it test it and get back on the road now the first step is just locating where the sensor lives so a couple things you can do number one take a look at the radiator and you have the upper radiator or coolant hose follow that hose to the upper plenum okay so this is where that hose ends and then just follow the plenum and typically you will find there it is the coolant sensor okay so just to give you another view top radiator hose follow it leads right into the plenum okay and there is your sensor so that's number one number two is try a google image search for your specific vehicle a lot of times you can take up diagrams and schematics if you still have trouble another thing you could try is this is an extra sensor I just happen to have for this exact vehicle but if you do a search on Amazon or Ebay or your favorite auto parts store look up the part specific for your vehicle and get a color photo of the sensor and then just try to match it up because these modern vehicles they're very very condensed everything is not in the open unfortunately so if you take a look at that sensor again and right now the harness connector is on there but this is the same sensor now unfortunately where the sensor lives it's a little deep in the engine bay but I think we have the lighting as best as we can get it before you begin just disconnect a negative terminal going to the battery and right where the flat-head screwdriver is right here this is where there's a little tab so just pressing that tab and you'll pull out the harness connector okay about a little bit so right here sometimes they could be a little difficult but I rate got it off I'm gonna just give you a different view it's a little tough it really is to get this but you get the idea you just going to slide off that harness connector now before you remove this sensor every vehicle is a little bit different if you want to be on the safe side you can drain a little bit of fluid sometimes when you remove this sensor some coolant may come out so if you want to be on the safe side drain a little bit of coolant and you won't have to worry about coolant falling and spilling on to the engine now the sensor in this case is an 18 millimeter end so the longer the wrench typically the better you are so as you can see we just slip over the end of the wrench over the sensor make sure you have a good grip to make sure it's really on there sometimes you can try rotating it but in this case it just won't work so we have to go this route make sure it sits on there real nice and then you're just going to pull towards you to loosen up the sensor and here's another shot doing this on another vehicle same size this happens to be an 1897 Nissan Maxima 19 millimeter just remove it from the plenum and once you remove it bring it over to the bench and we'll test the sensor so now we have the sensor on the bench and before we test the sensor very quickly p01 1:7 means that this is pushing out very very low voltage to the car's computer p01 1/8 means it's high voltage now what that means typically at idle this pushes out one to one and a half volts if you go under 0.3 volts that's p0 1 1 7 that goes over 4.7 typically that's p0 1 1 8 so all it means you may read something like low circuit that's just another word for low voltage essentially so that being said what I want to do is test the sensor to test the sensor we need a multimeter you don't have one of these you could pick them up typically for around 20 to 25 dollars Home Depot Lowe's Amazon local auto parts stores Sears Walmart they all have them and if you take a look we want to do an ohms test which is a resistance test and look for the Omega symbol on the multimeter okay now a good sensor right off the bat pushes out around 2 kilo ohms at 70 degrees Fahrenheit in other words the temperature inside the garage or outside wherever you're doing this now if that sounds confusing very very easy as you can see we have two weeks on the coolant sensor and two leads come with the multimeter all that I'm doing is touching these two leads to the coolant sensor does it doesn't that matter if black is touching left prong with the right prong or vice versa doesn't make a difference just just touch the leads to the sensor okay now typically what I do just just to make this easier on my end i'm going to use alligator clips you don't have to use these it just makes the job easier my end when i do these videos because it just frees up my hands essentially so again you don't have to use these but this makes it a little bit easier okay so i'm just going to hook up the leads and let's see what kind of reading we get so two point five kilo ohms so right off the bat oh I make sure you guys can see this there we go so right off the bat we get we have a good reading from the coolant sensor now what I want to do is apply heat to the sensor when you apply heat the reading should decrease when we take away heat the reading should increase okay so I'm just using a hairdryer here and here we go why some heat and as you can see the reading is decreasing now once I remove the heat we should see an opposite effect and there you go so now it's increasing if we apply heat again decreasing and once we remove heat it should go back up and there you go so that verifies let me just disconnect it that verifies that this sensor is working correctly now the reason why you want to test this sensor is because maybe have a wiring problem in other words you may have a triple code for a coolant sensor but the wiring maybe it's melted maybe it's not on all the way the harness connector maybe there's some water in there a break in the wiring so you always want to check the sensor always a good idea just to see what's going on and as you can see it's very very quick very very easy the biggest job really is just usually locating it and removing it from the vehicle so that being said I'm just going to reinstall this in the vehicle start everything up make sure it's in good shape and I tell then thanks for watching [Music]

Channel: CarsNToys

Views: 533,828

Rating: 4.7510014 out of 5

Keywords: engine coolant temperature sensor, engine coolant temp sensor, ects, p0117, p0118, coolant, temperature, sensor, sensor low circuit, sensor high circuit, mechanic, carsntoys, diy, diy auto repair, how to auto repair, how to, cars, diy auto, automotive education, automobile (industry), auto repair help, automotive (tv genre), google, youtube, coolant temp sensor, subaru p0117, subaru p0118, p0117 code, p0118 code

Id: vhputa79rLQ

Length: 7min 56sec (476 seconds)

Published: Tue Feb 13 2018