Code 52 Knock Sensor and won't start

[89gte]

Hello. I have a 89' 7MGTE that will no longer start and reads code 52. I have used the search function, and I think I've found all of the information I need to go through the rewiring process for the knock sensors. However, I still have a couple questions. If these have been answered before, I'm sorry if you know where or how to find them just tell me what to search.

This is my first supra and I purchased it about a week and a half ago. It had a rebuilt engine put in back in 2008. Almost everything has been running great (even came with original toyota tool bag and supra mats) until this Friday when I was heading out to a lake for the 4th. I stopped at a restaurant went inside, ate and came back out and the car would turn over but wouldn't start. Also looked like a little coolant leakage from overflow, but i topped it off. I messed with the wiring, checked lines and distributor but couldn't get it to go. Towed it back and got code 52 - knock sensor circuit. I am ready to rewire, but just wondering if the code will cause the car to not start ( retarding the timing)? From most of the threads I've looked at, I think i'm reading that most code 52s will still allow the car to start but cause performance issues. If that's the case, is there something else going on with my car? Code 52 is the only one the ECU is throwing.

Also, something that may not matter...the other day my shroud i think somehow came back and caught a fan blade breaking the shroud in half and taking one blade with it. In the process of replacing both but engine was still cooling fine.

 

[shipkiller]

52 will not prevent the car from starting. you got anonymous problems

 

[T3rril79]

That's right code 52 just gives you crappy gas milage (result of the added fuel) and retards the timing. I just go rid of my code 52 issue but it ran fine. I would start my diagnosis by trying to figure out if you are getting any type of spark

 

[89gte]

Thanks for the help. I will get on that right now. Also...code 52 is only to be caused by faulty Knock sensors (rare) , sensor wiring (transclusent), or bad ECU correct (even rarer)? Is there anyway my anonymous problem could be throwing the 52 code at me or do I have a unknown issue and faulty knock sensor too?
Thanks Joe

 

[jetjock]

The no-start and code are unrelated. 52 can not be set unless the engine is running. In fact not only does it have to be running but a bunch of other things also have to happen.

 

[T3rril79]

The issues relating code 52 are generally isolated to the sensors or the wiring going to the sensors. The chances of an ecu being dead is rare. Basically most likely you have 2 separate issues you are dealling with most likely.

 

[92TealSupra]

A lot of Code 52's happen because the wires at the plug starts to wear away or break. Check both knock sensor and see if the plugs are attached correctly. I had Code 52 once, it was my rear knock sensor wiring that went right to the plug.

 

[89gte]

Ok I figured out my anonymous problem. It was the wiring for the cam position sensor. For the moment, I just cut the old tape and made a better connection and it has started every attempt, but I'm going to redo it tomorrow. I have a new question though...I've driven it a couple days now for a while each day and the Code 52 has not come back since I cleared it. Could some other malfunction cause the Code 52 to go off? Or the previous owner have it happen and then fix, but never cleared it? Is it supposed to come back immediately? I have not noticed a difference in performance. Thanks.

 

[hvyman]

You just have not set the trip. Certain things need to happen for the trip to set. Unless since youve only had the car for a short time the po fixed it and never cleared the code. Could just be stored.