Code 43, Knock Sensor
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Car: 91 Z28, 2000 T/A
Engine: SBC 355, LS1
Transmission: T56, T56
Axle/Gears: 10bolt 3.73, 3.42
Code 43, Knock Sensor
Hey everyone, just wanted to throw my Code 43 experience up here. I read through alot of Code 43 threads and didn't come across this bit of info.
I have a 1991 TPI 350 car and all of the sudden started getting a code 43. Went through the factory manual troubleshooting flow chart and it says to test the knock sensor to ground and you should have 3500-4400 ohms of resistance. Did that checked good, then tested to make sure I had between 4-6v at the wire, had 4.98v. I basically followed the flow chart to the point of it telling me I had a bad Mem-Cal. Since heat effects resistance, I decided to test the sensor with it warmed up and throwing the code and the sensor was no good.
In short, make sure you test the knock sensor with the engine warmed up. Cold my sensor had a perfect 3900 ohms of resistance, but once the vehicle was up to operating temp the resistance was zero.
I have a 1991 TPI 350 car and all of the sudden started getting a code 43. Went through the factory manual troubleshooting flow chart and it says to test the knock sensor to ground and you should have 3500-4400 ohms of resistance. Did that checked good, then tested to make sure I had between 4-6v at the wire, had 4.98v. I basically followed the flow chart to the point of it telling me I had a bad Mem-Cal. Since heat effects resistance, I decided to test the sensor with it warmed up and throwing the code and the sensor was no good.
In short, make sure you test the knock sensor with the engine warmed up. Cold my sensor had a perfect 3900 ohms of resistance, but once the vehicle was up to operating temp the resistance was zero.
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