Video tutorial on how to replace the coolant temperature sensor for the ECU on a Toyota 3.4L V6. This engine is found on different Toyota models, however the truck I’m working with here today is a 2001 Tacoma. Typically a faulty engine temperature sensor will cause an increase in fuel economy, running rich which is shown by black smoke from the tailpipe, and in a severe situation you’ll have a check engine light.
Website: http://4diyers.com
Patreon: https://www.patreon.com/4diyers
Facebook: https://www.facebook.com/4diyers
Google Plus: https://plus.google.com/+4DIYers
Twitter: https://twitter.com/4DIYers
Instagram: https://www.instagram.com/4diyers/
Tumblr: http://4diyers.tumblr.com
Pintrest: https://www.pinterest.com/4diyers/
Tools/Supplies Needed:
-3/8” drive ratchet
-10mm deep and shallow socket
-standard screwdriver
-four new fuel rail crush washers
-temperature sensor
-17mm wrench
-20mm deep socket
-6 inch extension
-19mm deep socket
Procedure:
Ensure the engine is cold as you’ll be working around components which will be hot. When facing the engine, it’s on the left side under the front of the fuel rail behind the timing belt cover.
Loosening and removing the gear clamp on the upper radiator hose. Slide the clamp back so it won’t interfere with the timing belt cover. Remove the spark plug wire clips. One clip on the far left side has tabs that will need to be depressed and then push it out of its location. The other clips are removed by slipping your finger under the timing belt cover, then separate the clip and push it off the rear.
Using a 3/8” drive ratchet with a 10mm deep socket, remove the bolts on the timing belt cover. Most of the bolts can be accessed with the deep socket. For the bolt on the left side of the radiator hose, use a shallow socket. The lower bolt on the left side of the cover will have an electrical connector in the way and you can slide that off the clip.
Pull the timing belt cover back. This is also a great time to inspect the condition of your timing belt.
Press the tab on the side of the electrical connector and remove it from the sensor. Unfortunately, the sensor still can have direct access with a socket, the connection line between the two banks of the fuel needs to be removed, but not fully.
There will be some fuel present in the lines, you can pull the fuel pump relay, then turn the engine over to relieve some of that fuel and pressure. Loosen the 17mm banjo bolts using a wrench. Then only remove the banjo bolt on the sensor side. These connections have two crush washers on each side and they will need to be replaced, so four in total. Crush washers are intended to only have a single-use.
To remove the sensor, the one currently in the truck is a 20mm and a deep socket is needed. A 6 inch extension can also be used.
Remove the sensor, there will also be a crush washer which needs to be removed too and the new sensor should have a new washer.
As you can see, here is the new sensor. Using the new sensor as an example, while I am doing a dry test, a coolant temperature sensor should be tested in hot water with a specific temperature. Based on that temperature, you will see a specific resistance rating. Based on this chart, you’re able to see what the resistance rating is at a certain temperature.
Another way of testing the sensor or circuit is by using an OBD2 code reader which can monitor live data. While the vehicle is warming up, you should see the temperature of the engine increasing. However, this doesn’t test the sensor specifically but instead the whole circuit.
The new sensor also has teflon tape preinstalled.
Install the new sensor, this time around it uses a 19mm deep socket. The torque specifications for the sensor is 14ft lbs or 20nm.
Reconnect the electrical connector for the sensor.
Reinstall the connection on the fuel rail, make sure those new crush washers are installed, there is two on each bolt which does on both sides of the connection. Crush washers can be purchased online, at the dealer, your local parts store, farm equipment, or hydraulics supplier. The torque specifications for these bolts are 25ft lbs or 34.3nm.
Reinstall the timing belt cover with the 10mm bolts.
Reinstall the clamp for the coolant hose and tighten.
Clip-on the spark plug wires.
Start the engine and finally check for leaks around the sensor, fuel rail, and coolant hose. If leaks are found, make adjustments as needed.
Thank you to all those who watch my videos and support my content. Don’t forget to subscribe to my channel for future tutorial videos and like my video if you found it helpful. New videos are always being uploaded every week!
© 4DIYers 2013
All Rights Reserved
No part of this video or any of its contents may be reproduced, copied, modified or adapted, without the prior written consent of the author.
){kind=link}
Very awesome video. I have a 99 and it's idling high with code po505. I cleaned the IAC but only helped a little. Think new coolant temp sensor will fix?
Because if the clean and straight to the point videos you make I am new subscriber
Would this give off a P0115 code?
Very helpful! Thanks!!!
My sensor dont have any white stuff on threads.. what do i use? Or install like it is
What is the temperature supposed to be on these engines?
THANK YOU!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Hello,
What material are crush washers? Copper or aluminum? mm? Thank.
I just changed the Coolant Temperature Sensor, but now my 2001 4Runner won't start. I unplugged the EFI fuse for 30 minutes to reset the fuel delivery and still nothing. Any help is appreciated.
Thank you so much for this video. The instructions are spot on; and only for me to find the wiring had been split. So using your instructions, I removed the plug, soldered the wiring, & all is well!
Couldn't get new washers in my small town. The mechanic at the auto parts store said look at the washers closely, if they are just slightly scarred sand them gently with high grit paper, no less than 400. He almost always reuses them. He said they usually fail to seal because someone fails to clean the grit from all the surfaces. Also, be careful taking off the plastic top it's dark down there and with poor eyesight it's difficult to see that a narrow screwdriver will release the plastic prong that fits down into the sensor. You don't want to break that plastic apart.
My check engine light just came on and this is the code showing up.. It took a few tries to get my truck started first thing in the morning once it started the check engine light came on.
Thank you, 4DIYers! This was exactly what I needed. A real public service you are doing! …Funny, I copied down the instructions as your video went along, and then I saw that you had written it out. Well, now I know the procedure real well before I get started!
Part number for the sensor?
My gauge goes to red after changing sensor but the engine is not over heating. Any advice please
Can I splice into these wires to run an aftermarket temperature gauge?
I just bought a 96 s10 with a 2.2 liter v4. My temperature gauge didn't work at all so I replaced the engine coolant sensor. Now with the new sensor after the engine runs for about a minute and a half the gauge goes past redline even though the engine itself is cold. What else should I do? Did I purchase a faulty engine coolant sensor?
Just changed mine out, successfully. Thank you for the video. It was very helpful. If anyone cares, the torque value for the #1 timing cover bolts is 80 inch lbs. And I was able to do it without removing the lower left bolt on the timing cover. It's the hardest one to get out and back on. But if you are careful, it doesn't need to be removed. Thanks again, great video!
I can't even find a video on how to replace on in a 2.7L Tacoma, mine needs replacing and I want to make sure before I go and replace it.
My temperature gauge reads a little high on a cold start but then drops to about center after warming up a bit. Could doing this fix my problem? I recently purchased a Tacoma and just discovered that there is only water in my cooling system. I'm planning on doing a flush as well as changing the coolant temp sensor and the thermostat.