Valkyn71

Have been getting an intermittent SES light, usually at idle when im at a stop light or whatever.

Hooked my laptop up today and saw the only DTC code was MALF 43: ESC, So i did like on Shoebox's website and tested the voltage going to the knock sensor.

The volatage between the pin on the harness connector and the block was 4.9 volts (should be 5), the resistance of the same was 4300 ohms (supposed to be 4400 +/- 1000).

So what does this mean? I just put a LT4 KM in when i did a cam swap not long ago.

Could it be that the sensor isnt grounding to the block well? I didnt try grounding it to the outside casing of the sensor.

Any ideas?

Valkyn71

Just tested the resistance through the housing of the sensor, was right at 4200 ohms.

shoebox

Your results sound good. If your trouble is intermittent, it will be hard to track down. Could be that the wire is going open or you might have a spark plug wire too close to it.

Valkyn71

One thing i noticed was where the plastic harness plugs onto the KS, the piece it clips onto can pivot around in the sensor. Is this normal?

If i took some datalogs would i be able to tell if the KS was working correctly?

What kind of knock retard does the engine pull if this code is active?

shoebox

The clip will spin around on the sensor-not a problem (unless just making real poor contact).

Data logs will probably only tell you when the failure occurs (if it does).

I think up to 10° retard is what the PCM will do.

Valkyn71

So what do you suggest i do about it? Any thing else i could test to narrow things down?

shoebox

Ask any mechanic. Intermittents are the worst to track down (and even worse if electrical). If it would stay broken, you could probably fix it. You just have to keep trying things and ruling things out.

Valkyn71

Do you think i should replace the knock sensor to start?

Should i try clearing the codes, then driving awhile and see if it comes back?

shoebox

You can try what you think might help (personally, I hate to replace parts I don't know are broken). Yes I would clear the code or else you will never know if it is repeating.

Russtebo

I have this same problem. Though what was briefly intermittent is now constant. I was reading 0 volts, even directly from the PCM (Bypassed the wire itself, it wasn't fun to setup). I have a feeling the PCM is bad.

I had replaced the knock sensor when it first happened and it went away for a day or two. The part is only $15

Let me know if you find a solution.