red 95 z28 lt1

help me im getting code 43 which is esc fail, what exactly is involved, if its the knock sensor, i replaced it 3 months ago with a brand new ac delco one, could it be the wire, how can i test it out, my spark retard is 9.0 right now. please help

shoebox

http://shbox.com/1/4th_gen_tech2.html#knock_sensor

red 95 z28 lt1

ill give that a try tommorw, i am pretty sure i have 5v to the wire becaues i tested it before i last changed it but ill look into it

red 95 z28 lt1

update

ok checked for 5volts to ground on connector terminal w/ key on engine off, 4.9v.

checked when it was plugged back in checked wire to ground and i get 4.9 volts as well

where do i begin, could it be a bad wire or knock module maybe

Injuneer

What about the rest of Shoebox's test procedure? With the wire off the sensor, measure the resistance from the single pin on the sensor to the block (ground). Should be in the range of 3,500-4,500 ohms. I suspect yours is going to read close to infinite ohms, which would confirm a sensor failure. None of these tests have anything to do with the knock module. There is a separate code (DTC 47) for the knock module.

red 95 z28 lt1

ok this may sound stupid but on my digital multi meter where on ohms do i set it at i have; 200, 2k 20k 200k and 2m

red 95 z28 lt1

ok with the meter set at 20k i get a reading of 3.88 ohms. does that mean i have aprox 3900 ohms?

red 95 z28 lt1

ok just logged my car on datamaster, at idle i get as much as 9 deg knock retard, but when i rev it over 2500 rpm it goes to 0 then when i go back to idle it will climb back to 9

Injuneer

Do you still have DTC 43? If so, the PCM is using a default calculation, and applying knock retard liberally to protect the engine. It is no longer using the knock sensor input.

If you have 3900ohms across the sensor, when you hook the single wire back up, you should see ~2.5V between the single pin on the sensor (make sure you measure the voltage on the sensor pin if you can reach it) and the block. The PCM sets DTC 43 when the voltage on the circuit is outside the limits of 1.5-3.5V. If you probed the wire and not the sensor pin and got 4.9V, you may have confirmed that the harness connector is not contacting the sensor pin.

red 95 z28 lt1

so i could be having a connection problem? because im still reading 5v probing the wire while connected.
i cleared the dtc and it came back. ill check again but how do u get to the pin when its connected to check voltage?

red 95 z28 lt1

anyone?

red 95 z28 lt1

its been a while but im still having the same problem checked my connections at the knock sensor and i am still getting 4.88 volts with key on from pin d22 to ground, i probed the wire, is it possible that the wire is touching another wire that is going down that area like a starter wire or an o2 wire, i repaired them before because they were burnt, knock sensor reads 3900 ohms, i get same voltage when unplugged (4.88v)
still have code 43

i tried using edit to desensitize it and wiped out the pcm so it went back to madz28 for repairs and he made the adjustments, still getting same code same problem

just realized no matter how much i desensitize it i will still have problems because its a circuit problem. Correct?

Injuneer

Are you saying that the end of the wire with the connector is reading 4.88V whether it is connected to the knock sensor or disconnected from the knock sensor?

red 95 z28 lt1

update

ok i found the problem, i decided to go for a drive at first the check engine light was going on and off randomly and the car was running good then poor randomly, went and got gas and went home car ran fine the whole way home no check engine light nothing seemed wrong

checked voltage right away while everything was connected and got 2.4 volts key on

Injuneer you are right its a connection problem either a bad splice when the wire was burnt up and repaired or a loose or bad connection at the sensor.

thank you for all your help