My celica has been throwing code 52, Knock Sensor, for a while now. When the code first came about I replaced the ATS knock sensor that was on it with another ATS knock sensor that I bought from ATS. Due to the code not going away I first checked the connection to see if it was connected properly, everything checked out fine. I had enough of it so I took the car to a real good electrician in my area. He said that the problem doesn't lie with the sensor, but with the ECU; it isn't reading it. He told me to find out what was used to program the ECU and then he could help me. This is what led me to question, is it really my ECU that is doing this and how can I figure out for sure where the problem?

This post has been edited by cibrit-: Apr 27, 2013 - 4:20 PM

Check your wiring, there is a grounding shield on the sensor that if cut could lead to issues or loose wires coming apart somewhere, maybe even an ECU going bad.

I stay away from that electrician, because he is not an electronics technician.

This post has been edited by soulshadow: Apr 27, 2013 - 7:53 PM

have you checked to see if the engine is actually knocking?

Open up the case on the ecu and check for any blown capacitors. Thats about the only thing that goes wrong on these ecus.
If that looks good, then check on mr2oc. There is someone on there that sells a really nice knock sensor wiring kit that will replace the wiring going to the knock sensor with brand new, properly shielded wire.

This is normally a wiring problem caused my cutting/splicing the shielded factory wiring.