I've been trying to track down a random hesitation for a while now and I think I may have a lead on what's happening. I've been logging some driving for a while (using TTS Datamaster) and noticed I'm getting an almost constant amount of knock retard. It's been pegging out an 8* retard through most of the driving. I've also found the computer throwing a code 43 - ESC failure. I checked Shoebox's website and it says Knock Circuit failure. I followed his instructions to test the knock sensor and everything seems fine. I get 4.7V at the wire harness with it disconnected and 2.6V with it connected. I have about 4200 ohms of resistance on the knock sensor. I was also running an LT4 knock module and swapped it out for the desensitized one that came with my tuned ECU. same results with either KM. I also reset the PCM and cleared the code. About 20 seconds after starting it back up, the code set again.

How does a code set if nothing in the ciruit seems to be wrong? I'm wondering if the ciruit is bad, is that possibly why it's pulling so much timing? can false knock cause it to throw a code 43?

 

Are you measuring the voltage between the single wire in the harness and the engine block? Are you measuring the resistance of the sensor between the single pin on the sensor and the engine block?

Once the code it set, the PCM calculates knock retard internally from the engine operating parameters, and ignores the knock sensor. It's almost always a large number varying from 3-12deg.

 

I checked the voltage at the end of the harness (sensor end) the resistance was checked from the pin to the block and I got about 3800 ohms and then 4200 ohms when I checked from the pin to the sensor.

 

I just deleted my thread in LT1/LT4 engine tech because it is about the same thing. I replaced my KS because the stock one wasn't reading at all (resistance). I get 4.75 V from the wire and 3900 ohms from the sensor. I know it is grounded because I tested from the sensor to the block. Is it possible to have a bad connection somehow? I didn't mean to jack the thread, but I'm having the exact same problem. What else is there to check in the system relating to the code 43? Maybe my LT4 KM is bad, but how would I know that? Will that throw that code?

 

DTC 47 = Knock Sensor (KS) module circuit or module missing

Another possibility is some sort of voltage being induced in the wire by a nearby high voltage wire, like a plug wire, running parallel to the KS harness wire.

 

Would there be a variation in the voltage (if indeed voltage is being induced in a nearby wire) if we were to test the wire with the car running? It should still put out ~5V, correct? I appreciate the help Injuneer, as always.