4A-GE Knock Sensor

[Raikom]

Hey guys new to here i have a question that ive googled and can't seem to find the answer my AE111 Trueno 4A-GE 20V blacktop is popping error code 52 which i understand to be the knock sensor am i right in thinking that it is located under the intake? which is the best way to get access to it? removing the front pipe and starter moter to get my hand up in there or removing the intake and going from the top?

thanks for any advice given

Raikom.

[Lloyd]

[Raikom]

Thanks for the reply so would you recommend going from the top or bottom to access it?

[Raikom]

also im under the impression its torqued on? anyone know what it needs to be torqued to when i put the new one in?

[ALES_AE111]

Per blacktop service manual, torque is 45Nm / 450kgf.cm / 33ft.lbf.

Never taken the knock sensor out myself, so not sure what the best way to it is.

People on another forum seem to recommend removing the plenum from the top.

[Raikom]

awesome thanks!

[Kiwi-Corolla]

Changed mine once. When you remove the plenum you'll have more room to move, but it's still a bitch of a job. You'll need a long ass extension and a big 27mm deep socket. It's much easier to see the sensor from the bottom, so if you've got a mate handy get them to put the socket on from the top as you direct them from the bottom, otherwise you could be poking around for a while trying to get the socket on.

[Stu-]

It would pay to check the wiring as of all the knock sensor issues I've solved for people its always been the wiring. The shielding needs to be intact and run all the way to the end but not be grounded at the sensor end.

[gepsk8]

On 16v you can remove from under the car, a lot easier on hoist. Can't see 20v being much different, 27mm deep socket or don't waste your time.

[Raikom]

i think ive found the knock sensor though it was in a little bit of a different spot than that picture it was more between the the 2 middle throttle bodies orange ring on it also how do you test if the sensor is malfunctioning?

[Kiwi-Corolla]

Yeah the knock sensor is almost right in the middle, the other photo above looks like a 16v block. You can test it using a multimeter by putting one side on the terminal inside the sensor and the other side on the body of the knock sensor (the head). If there's no continuity it's fine, if there is it's stuffed. If you're getting code 52 then chances are the sensor is definitely poked anyway, but just give the wiring a bit of a wiggle just incase it's a loose connection.

[Raikom]

awesome thanks! So if i run the multi meter on it and i get no reading its fine? but if i do its stuffed im just a little bit confused as electrical is really my weak point

[Kiwi-Corolla]

Yep, if you get a reading on the multimeter then it means the sensor needs replacing. The knock sensor on the 20v is the same as a wide range of other Toyota engines, including the ever so common 4A-FE/5A-FE engines, so it would likely be easier to just grab another knock sensor from Pick-A-Part and see if the problem disappears.

[Raikom]

sweet as ive got connections with a Toyota New Zealand parts manager so ill likely go new and get it through him as i got a few other parts i need for it too

[Raikom]

I seem to have lost my torque ratchet do you guys think i could get away with just using a power bar and making it tight as $&#$%? or anyone out west auckland have one i could borrow for tomorrow?

[GDII]

45Nm is less than half the torque of a wheel nut of 110Nm. A power bar with one arm can do well over 110Nm. Either get a proper torque wrench or don't do it up really tight.

[Raikom]

im getting this reading from the sensor is it stuffed? the number fluxuates also

[Raikom]

also does the wire thats not covered just before it goes into the plug need covering

[Kiwi-Corolla]

I'm no auto sparky but the Blacktop repair manual specifies that if the sensor has continuity then it should be replaced, so based on that I'd say it's definitely in need of replacement if you're getting any reading other than zero. The sheath doesn't need to cover the whole wire, a lot of plugs in the engine bay are like that. That's how it comes from factory

[Raikom]

only when the multi meter was on that setting i would get a reading im not sure what setting to have the multi meter on to check it but toyotaspares has a sensor for $58 with a student discount so might just grab one of those and test it before forking out for a new one