5.7 Vortec Excalibur Knock Sensor

[Daryl]

Is it possible that the wire or the connector isn't any good? - I'm a computer guy - not a mechanic - so it seems possible to me that a bad/corroded/broken wire might be possible.

interesting thread - good luck

[Muzzab]

Thanks Daryl for the tip.

I had already looked at the connector as a source of the problem and decided to modify the connector as I thought the original was lacking.
So I found a male bullet electrical connector that if you grind the end off makes a much better electrical connection.It connects over the outside of the sensor pin.
I have also tested the continuity from the sensor connector to the ECM plug J1 in 17 and checked the resistance which showed as zero/ohms

See the attached photo's .
Knock 3 shows the original vs. modified connector
Knock 2 shows installed into a sensor.
Knock 1 shows installed on a brand new Nautique. parts supplied sensor on the engine.

Please keep the suggestions coming to fix this problem.

[Muzzab]

More Checking - The below is and extract from the MEFI 4 Diagnostics manual ( page 259 of 337 ) for trouble shooting a Knock sensor DTC 44

I'm trying to figure if I have the correct resistance for what is specified in the test.

Leaving the wire connected to the sensor and removing the JP1 connector from the ECU from pin 17 I measure 3.85 k ohms resistance to ground.
This is nearly exactly the same as just measuring the Knock sensor alone on the bench.( see attached photo )

Does this indicate a fault that the wire is a problem and should have more resistance ???? ie 93 - 107K resistance as per the procedure ?











5.0/5.7/6.0/8.1L Diagnosis 5 - 117
MEFI 4 - PCM
DTC 44 - Knock Sensor (KS) 1 Circuit (Scan Diagnostics)
Step Action Value Yes No
5
1. Install scan tool.
2. Select the option to view the data list.
3. Select to view the knock signal 1 parameter.
4. Disconnect “J1” harness connector.
5. Connect a DMM from “J1-17” (CKT 467 - Knock Signal
to a known good ground near the knock sensor.
Is resistance between the specified value? 93-107K

[scottb7]

This is probably not going to add value but I found this post for a jeep. I clearly understand from all your work you want to fix this correctly. Go for it. But I have found that once in a while you gotta call it and move on.

I thought the use pvc tape because they can hear too well, and the idea to plug the hole and tie to firewall were interesting ideas.

PS. I was wondering as a work around if you could take the wire from the one throwing the code and simply spice into the side that is not throwing the code. It is a work around but then ECM gets a signal to both sides that is probably a valid signal.

http://www.jeepforum.com/forum/f12/k...-code-1497016/

[scottb7]

I found a few more posts - about cars - where they used one knock sensor to feed signal to both sides...You can probably make a pigtail so you don't have to cut any original wire.

[jhersey29]

The gt40 has a knock signal amplifier. If you follow the wire can you find something else inline that maybe amplifies the signal. Big difference being ford versus Chevy but maybe worth a look.
Sent from my RM-877_nam_att_205 using Tapatalk

[Quinner]

Is that Teflon tape on the sensor? If so lose that and try again.

[ski4evr]

I have discovered that for my 05 excal, parts from a 98 vortex 350 fit (except the plug wires). This article might shed some light, not sure. Looks like there are two different sensors.
http://www.fullsizechevy.com/forum/g...nce-specs.html

[Muzzab]

Happy new Year to all.

Well I think I have finally had some luck in trying to solve this Knock sensor problem.
I went to the lake specifically to try to solve this problem armed with the Diacom and various sensors and wiring harnesses.

I tried many combinations and was puzzled as to why I kept getting a "Knock Sensor 2 Inactive" on the Diacom. The 5.7 should only have one Knock Sensor.

The final solution was to run two knock sensors .No1 connected in the original lower block drain hole and wired to pin 17 on the ECU.
No2 connected to the bolt hole via a right angled fitting next to the harmonic balancer ( see earlier post ) and wired to pin 1 on the ECU.

This is totally against the wiring for a 5.7 but somewhat in line with the 6.0 engine.

The sensors I am running are different part numbers and " used " sensors as the " new " sensor from Nautique spares did not seem to work. This could have been because I believe with the duel set up that appears to be working the sensors need to be matched by AC voltage output and harmonics.

The triggering of the DTC fault was not from an extra load on the engine but specifically at around 3300 rpm. You could see via the Diacom that the ECU was doing it's job and as soon as the DTC was tripped the timing advance was retarded by 5 degrees from around 33 degrees back to 28 degrees at the 3300 rpm's.

With this set up the engine seemed to run strongly to WOT and not throw a DTC.

So we are heading off to the river for a weeks holiday which will be the real acid test to see if this is a long term solution .

Thanks to all for your suggestions and I will report back on return.

Cheers. MuzzaB

[8urchvy]

Ok. I've been reading about knock sensor issues and I'm having this same issue on my 2007 220 with the PCM 330 5.7L.

Ok. I Replaced the plugs and new knock sensors but the didn't fix my knock sensor warning from going at about 3,500 rpm maybe 25 mph.

The boat had some old gas in it from a previous owner (like 1/4 tank). I filled it with 91 octane and put in fuel conditioner. But the sensor still goes off.

Any ideas???

At the river now in Parker AZ !

[Muzzab]

Have you been clearing the code with the Diacom software.??
Torque the sensor correctly? No thread tape on the sensor to ensure a solid earth connection.
If you have access to the Diacom software , its worth checking your cam retard setting value.

Knock Sensors can be really difficult to fault find sometimes.

[obd666]

hey Muzzab, did you have to clear the code each time via the software? also, did you ever find a way to test just the wire & connector from the ecu? here is my thread, i changed out my knock sensor and now have the error ...

http://www.planetnautique.com/vb5/fo...-throwing-code

[Muzzab]

odb666.
In my experience you can only clear the code properly using the Diacom software.
If you check there web site I believe you can by a smaller plug in module to the ECU that will clear the diagnostic trouble codes. The method you describe in your thread buy holding the two buttons on the gauge will on clear the code temporally.

To test the wire, simply disconnect the main loom ( marked J1 ) on the ECU and find wire marked "17 " ( it was light blue in colour ) and check for continuity between the loom and the knock sensor plug with a multi-meter.

The connector for the knock sensor is not ideal and replacement with the modified "bullet" style connector described in the pictures above really gives a better electrical connection.

Let me know how you go!

[emjayem]

Just had a thought as I am reading this and trying to figure out my own issue, but, Knock sensor 2 may refer to the knock sensor being on bank 2. Also, is it possible that the additional KS you put in is on the intended circuit and the other may not be? Ever try unplugging that original one and running just the new one you put in? I assume you ran a new circuit for it, or is it just piggy-backed in?

here is my issue if you care to take a stab at it! http://www.planetnautique.com/vb5/fo...4-san-no-start