f4mdtwr

How would I know if my knock sensor module is not functioning? Is there a test I can can run? I think I narrowed my issue down to the module, but before I change it I want to check if it's still working.

defaultexistence

iTrader: (11)

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

f4mdtwr

MODULE, not KS. The module that is located in the PCM.

shbox

I would imagine that the KM would have to be working for you to get any knock counts. Knock can usually be simulated with some hammer raps on a solid part of the engine.

pboxfun

iTrader: (2)

Well if you find out that you Knock Module is bad I have one I can sell you for real cheap. Works perfectly fine. Just PM me.

I hope you figure out what the problem is!

f4mdtwr

shbox,

I followed all of instructions, I check for the 5V (checked out), I check for ohms on the KS (checked out), I even check a new KS at the local parts store and I got the same reading as the KS that is in the engine... I even check to see if the knock sensor was counting knocks by putting a multimeter at 2V AC and got no change in the meter when I hit the block. I don't know where else to look. Am I missing something? I know the code is still there because when I ran the scanner again and it's still showing DTC43 (ESC). This is what the scanner read...

Codes Present: Yes
A.I.R pump: off
AC Clutch: off
AC Evap (F*): 20
AC Press (PSI): -11.28
AC Press (V): 0.04
AC Request: off
Baro ("HG): 30.08
Baro (V): 4.86
Battery (V): 13.8
LT Fuel TR CL: 16
LT Fuel TRM L: 128
LT Fuel TRM R: 128
Evap Duty (%): 0
Coolant (F*): 206
EGR Duty (%): 0
EGR VLVPOS: 2
Engine RPM: 550
KS Counter: 4829
FC1 Relay: On
FC2 Relay: On
IAC Position: 12
Idle Req RPM: 538
Inj L PW (Vm): 0
Inj R PW (Vm): 0
Knock Ret (*): 0
Loop Status: Clsd
MAF: 0
MAP (HG): 10.03
MAP (V): 1.25
IAT: (F*): 72
O2 Left(Vm): 932
O2 Right(Vm): 937
Run Time: 10:59
Skipshft Ena: No
Spark Adv: 20
Throttle (%): 0
TPS Sensor: 0.63
Vehicle Speed: 0

shbox

If the "KS counter" on your scanner never increments, I think I would change the KS anyway. Or try someone else's KM.

f4mdtwr

shbox,

If the complete PCM was fried would the engine turn on and stay on? Just trying to weed out potential issues. I know the knock counter is ticking away and the "knock count" increase the longer I leave the scanner on, so that leads me to suspect the knock sensor is working properly (at least that's what I think). I just want this issue to go away and I can't seem to pin point where to go to make it go away.

Thanks,
Jimmy

Gojira94

iTrader: (4)

A little more detail about the car? What year and what mods have you made to it? I see it's idling at 550 with 20* of timing. Has someone been fiddling with the tune?

ESC modules ("Electronic Spark Control") were phased out by GM around late 92, early 93, IIRC. So that leaves the knock sensor, wiring issues (pinching/ chafing somewhere), and possibly ignition module.

Lastly, have you tried clearing the code and seeing if it comes back? Sounds like there's an issue here and it probably would, but just checking.

f4mdtwr

Go94,

It’s a custom rock crawler buggy. Engine is completely stock, minus all the smog BS. Nothing was performed to the engine other than re doing the wiring harness and removing all of the BS in the PCM to allow me to turn the engine over.

As far as the (ESC) module. This is part of the message code that is displaying when I run the scanner. It states DTC43 (ESC) “Electronic Spark Control”. I installed a new pigtail because the old one looked like it was in its last few days. I first soldered the 2 wires, but I did not work very well so I crimped the 2 wires together with a crimp butt. Everything is getting very good contact from what I can see. Please excuse this stupid question… How is there a connection between the ignition module and the knock sensor? The engine turns on and stays on, it’s not erratic, it idles just fine.

Clearing of the code… Done! Every time I run the scanner I clear the code before I run a error code scan and it keeps reappearing.

NOW WHAT?

f4mdtwr

Sorry, It's a 1995 LT1 F Body... The computer was adjusted by LT1wiring.com to make it a standalone.

Gojira94

iTrader: (4)

Ok, much clearer...

The PCM is the link between knock sensing and spark control. More knock = more retarding of the spark timing to avoid detonation, module delays command to discharge the coil by a few thousandths of a second.

What pigtail did you splice in? the one for the ICM or a different one?

Of course, you might be looking at needing to adjust the tune to desensitize the reading for that code in your application so it doesn't register under otherwise 'normal across the board' readings in the PCM.

f4mdtwr

I spliced in the "OEM" looking pigtail. Tom at LT1wiring.com is telling me that it's still the knock sensor. I am thinking it's not, but I am going to go ahead and change the knock sensor since it's under warranty. I don't think it will hurt anyway. If I continue to get the same error code, then I'll look into reprogramming the PCM to desensitize the knock sensor. By the way, if I desensitize the knock sensor will that hurt the engine? I am really frustrated with this freaking code, it needs to go away soon or I will need to burn and trash the LT1. This can't be that difficult.

I'll ask the question again. Is there a way to test the knock module to see if it's working? My guess is that the knock module is done.

Last question. If the PCM was fried would it allow the engine to turn over and stay on? I am just trying to weed out things here. I am also getting desperate.

Thanks to everyone who has responded.

mguidry629

iTrader: (6)

I had the same error code and it was the knock sensor. Switched it out and no more code. Of course, I had different results when I tested the volts and ohms. Wish I had more to offer. Hope you figure it out.

Gojira94

iTrader: (4)

No need to desensitize the knock module unless you run roller rockers. Guys do this or run a KM from an LT4 (came with RRs) when they add RRs so the knock count from false knock (added RR valvetrain noise) doesn't cause a problem.

Since you have a stock valvetrain, no good reason to desensitize the KM. That would just increase the potential for detonation. I agree with your move on changing the knock sensor (bottom of the block right side, just above the oil pan, in front of the starter). If you want a spare KM (inside the PCM) for troubleshooting I'll send you a stock LT1 KM. No reason to suspect your wiring job if it's sending knock increments to the PCM (working).

Make sure the knock sensor isn't one from a 96-97, btw. Different part from the 93-95.

f4mdtwr

Go94,

Cross referenced the OE part number to the autozone part number so i am hoping that I it's the same one. I'll change it today and report back with results.

f4mdtwr

Has anyone ever been lucky and removed the knock sensor the first time they turn the ratchet? This is the second time I change the knock sensor and it has never come out using the socket/ratchet. Used PB blaster and still nothing. Now onto the vise grips or pipe wrench... Always a mission to get this off.

f4mdtwr

To all,

Is there a torque spec for the knock sensor?

RamAir95TA

iTrader: (2)

Tight enough so it doesn't fall out.

f4mdtwr

Changed the KS and still getting the same error code DTC43 (ESC) electronic sensor control. FFFFFUUUUU%%%%%KKKKKK! What the hell is wrong with this engine?

Now what?