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Discussion Starter #1
So I have the code for knock sensors and I recently replaced the front one. or I assumed I did and I was trying to get to the one by the starter so I had to go under the car, and I looked and saw the front one I replaced and spotted what looks like another knock sensor next to it? under intake runner number 3 and I’m not sure if I replaced the right sensor now since they look exactly alike and the one plug fits in both sensors? Can someone tell me which one is the correct one? And what wires I might be missing? (The last picture is the old sensor I took off)
 

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other way around

7mge non turbo uses 1 knock sensor. the block has the boss for the 2nd but its not tapped

7mgte uses 2 sensors
 

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My bad......
Yes GTE has at least 2.
Actually, my late model, thick main web block has 3, all tapped.
The center was the GE location, front & rear are the GTE locations.

Mistyped by arthritic finger.
 

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Discussion Starter #5
My bad......
Yes GTE has at least 2.
Actually, my late model, thick main web block has 3, all tapped.
The center was the GE location, front & rear are the GTE locations.

Mistyped by arthritic finger.
So I have a total of 3 knock sensors? Would one not being plugged up throw a CEL?
 

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No, only 2, you may have 3 tapped bosses to screw them into.

All your questions can be answered by picking up a used MkIII genuine Toyota shop manual, or looking at the on-line version.
On line factory service manual

These manuals also have really easy to follow diagnostics.
Hard copies go for $35 to $60 on eBay.
 

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Discussion Starter #7
No, only 2, you may have 3 tapped bosses to screw them into.

All your questions can be answered by picking up a used MkIII genuine Toyota shop manual, or looking at the on-line version.
On line factory service manual

These manuals also have really easy to follow diagnostics.
Hard copies go for $35 to $60 on eBay.
alright cool thanks just was weirded out seeing another one just not plugged up. Now to get back to the top starter bolt...
 

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Speaking of Knock sensors.

has anyone been adventorous enough to remove the 1 wire sensor and put a 2 wire sensor in its place (wiring one pin to the stock knock pin on the TCCS and the other pin to 0V sensor ground).
 

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I have bought 2 of the Nissan/Bosch/Siemens style knock sensors to go along with my Infinity 6, and the required stepped stud to put them on the 7M, but haven't got it all together yet.
They are supposed to react to more actual ignition knock, and less of mechanical noise than the original Toyota sensors, giving a cleaner signal.

The Knock sensor itself is a Bosch sensor, part number 0-261-231-006.
(Toyota # 89615-20090, )

You use a Toyota stud, part number 90126-08046.
 

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I have bought 2 of the Nissan/Bosch/Siemens style knock sensors to go along with my Infinity 6, and the required stepped stud to put them on the 7M, but haven't got it all together yet.
They are supposed to react to more actual ignition knock, and less of mechanical noise than the original Toyota sensors, giving a cleaner signal.

The Knock sensor itself is a Bosch sensor, part number 0-261-231-006.
(Toyota # 89615-20090, )

You use a Toyota stud, part number 90126-08046.
You mean like this

20200217_091604_copy_3427x1622.jpg 20200221_201402_copy_1541x1976.jpg

:)
 

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Did your code get resolved? One problem these cars have is that the shielded wire for the knock sensor gets grounded somewhere along the line on its way to the computer. You can check for grounds by unplugging the knock sensor and also the plugs on the computer and test for continuity with an ohm meter. It shouldn't be grounded with both ends of the plugs pulled and there should be continuity when running a loop wire to both ends with the Ohm meter in the middle.(Confirms there is no open circuit also) The schematic for the plugs is available using the online Supra manual. It's best to have a year specific manual to be sure. The shielded wire is unusual and doesn't look like any of the others. It's kind of a thick clear plastic cable. I had to run a bypass wire from the computer plug to one of my knock sensors on an old harness that I had. I've since replaced it with a better complete harness. Using a shielded wire is recommended though to prevent erroneous signals. Knock sensors are easily damaged. I broke the plastic nose off of the one that's back by the starter. Since then, I use a U-joint socket extension to angle away from the knock sensor for safety's sake. Like what was said before: a turbo engine has 2 knock sensors. One near the front and one near the rear. A non-turbo has a single knock sensor in the middle.
 
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