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Discussion Starter #1
Does the ECU do anything other than light up the check engine light? Does it go into any kind of limp mode or anything? Im not sure if its me or my imagination, but when that light comes on (code 52) the car feels a little slower.
 

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Not ur jizz, not ur bizz
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the car does go on limp mode. Your car will be slower and you will lose gas milage and the car will run richer.

solve the problem and itll all go away.
 

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Discussion Starter #3
Johnny Dangerously said:
the car does go on limp mode. Your car will be slower and you will lose gas milage and the car will run richer.

solve the problem and itll all go away.
Ah, i thought the car became a total dog. Sometimes i start it up and can drive fine without the check engine light coming on. Then other times it comes on after just a minute of drving (always code 52) So when the light isnt on is the engine operating normally?
 

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yes


i bet you you have a loose wire in there OR a shitty sensor. I ended up having a shitty sensor.
 

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Discussion Starter #5
Johnny Dangerously said:
yes


i bet you you have a loose wire in there OR a shitty sensor. I ended up having a shitty sensor.
I'm hoping its just a loose wire. When i did the HG there was a wire from one of the knock sensors. We put it back on, but the other one or that could have come off. The car only has around 65,000 miles on it, so i doubt the sensor is fried.
 

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yeah, well on the plug and wire theres a rubber grommet type looking thingy-ma-bober that if comes loose..could result in the wire not hitting the sensor correctly thus causing code 52

push that bitch in with a small flat tip screw driver and see where it goes from there.
 
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kind of ot but with a bad oxygen sensor and the dummy light on would it be in limp mode?
 

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yeah i think so
 

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The engine will be out of limp mode as soon as the light is off. And it makes such a difference - before I did mine my best 0-60 was over 10 seconds. On the first try after fixing it, i went 0-60 in 7.5 seconds. I was pleased! Have you solved it yet? Rewiring is not nearly as daunting as it looks.
 

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Discussion Starter #12
purple_car said:
The engine will be out of limp mode as soon as the light is off. And it makes such a difference - before I did mine my best 0-60 was over 10 seconds. On the first try after fixing it, i went 0-60 in 7.5 seconds. I was pleased! Have you solved it yet? Rewiring is not nearly as daunting as it looks.
There is deffinately a HUGE difference. When the light comes on my car is a dog and doesnt like building boost it seems.


Is there a way to test the knock sensors to see if they are functioning.. i checked the wires and they seemed to all be ok, but i still get the code 52 randomly.. sometimes i can drive for 15 mins before it comes, sometimes its after just a minute.
 

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The wires themselves will not appear to be worn or broken in any way, but for some reason they are shorting out somewhere (assuming the sensors are ok, which according to the supras.com write up they almost always are).

My check engine light would come on after a few minutes of driving when I had the problem.

Have you seen the write up at http://www.supracentral.com/oldschool/htm/knock.htm

(I'm sure you have seen this).

I would bet it's faulty wiring, and since it only costs about $15 in wire/solder, it doesn't hurt. It took me and a buddy about an hour and a half, I was scared to touch the ecu but after we started digging around we realized how easy it was.

New knock sensors are something ridiculous like $200 each, so definitely try the rewire first. Do you have a pre or post 89 supra? Aparently with the post 89's it's hard to get to the second sensor, but some people say they can get it. With my 88 we did not have to remove the starter, although my buddy did have small and agile hands.

Good luck!
 

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Discussion Starter #14
purple_car said:
The wires themselves will not appear to be worn or broken in any way, but for some reason they are shorting out somewhere (assuming the sensors are ok, which according to the supras.com write up they almost always are).

My check engine light would come on after a few minutes of driving when I had the problem.

Have you seen the write up at http://www.supracentral.com/oldschool/htm/knock.htm

(I'm sure you have seen this).

I would bet it's faulty wiring, and since it only costs about $15 in wire/solder, it doesn't hurt. It took me and a buddy about an hour and a half, I was scared to touch the ecu but after we started digging around we realized how easy it was.

New knock sensors are something ridiculous like $200 each, so definitely try the rewire first. Do you have a pre or post 89 supra? Aparently with the post 89's it's hard to get to the second sensor, but some people say they can get it. With my 88 we did not have to remove the starter, although my buddy did have small and agile hands.

Good luck!
I have a 91T... its a little tricky to get at the sensors, but i think it can be done. All i need to do is get the jack to come off so that i can re-wire it, and i can easily do that. Thanks for your help.
 

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Discussion Starter #15
Well i got it all fixed. I recrimed the wire onto the connecter and re grounded it aswell. The ground was totally disconnected... the supra runs soooo much better now

Thanks guys
 
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