WTF!!!

[Gregmckenna]

so to make a long sotry short I have a knock sensor code flashing (22) ... I have replaced the knock seonsor an in the process noticed the fool who owned the car befor me had the cam crank and knock sensor wires all spliced woith no original clips or harness;s.... so fair enough I took it all apart (1 at a time) an spliced em together... saullders... shrink tube... an still a code 22... is there 2 knck sensor wires or just 1... does 1 act as a ground.... what am I missing Im so fed up with this car I want to send it to a junkyard Ive tryed searching Ive beat walls Ive yelled an pulled my hair out Ive had 3 lisenced mechanics under the hood an they cant explain it Ive owned the car 6 months with this code... Im tired of 5 psi so could somebody please try to help me!!

[93Leg-c]

IIRC, my knock sensor only had one wire. This is on a '93 ss.

[93Leg-c]

Oh, one more thing, after replacing my knock sensor and clearing the ecu, code 22 still came up. That surely was frustrating. So, I unclipped all the engine wiring and re-connected them. The flashing code 22 went away. I'm talking about disconnecting and then simply reconnecting, not just the knock sensor wire, but other engine wiring connectors too.

I mentioned this to one of my buddies today. He's an aircraft mechanic. After replacing sensors and stuff on airplanes, he says sometimes the codes still come up. So, he (and other mechanics) disconnect the wiring harnesses and re-connect them. Quite a bit of the time, the codes then go away.

I don't know if that will help but it's worth the try.

[Gregmckenna]

well the batery was out for 4 weeks during paint an stuff an alot of the clips were screwed but when I get home from work Ill try that... do I unclip from the ecu to

[NuclearBacon]

the knock sensor has one wire but its a "shielded" wire. this means the "inside" inside of the wire has the information (being resistance in this case) and goes to the ECU. the "outside" inside of the wire is actually the "shield" which runs to ground. if you look at the wiring diagram you'll see a diagnoal back and forth wire zig zagging over it....

i actually was chasing a code 22 for many many moons....

found out i had a broken wire. I ran a wire from the inside inside wire to the ECU, grounded the other... check engine light went away... and has been out for 5000 miles.

hope that helps!

[93Leg-c]

I didn't disconnect/reconnect any ecu clips. They're usually very tight. But the engine wiring harnesses gets vibrations, dust, etc. so they are the ones that are more likely to have a marginal/bad connection.

NuclearBacon's post has good advice to follow, too!

[Gregmckenna]

yes! thanks alot... I havnt had a chance to try these however the chelded wire was whatI was wondering about as it is just sorta dangling in the wind an I wondered if the sheild didnt need some sort of ground... do I ground the cheld to the body or is it grounded to the ECu an suposed to be in tact to the knock sensor... as for resistance if the ecu measures the wire in resistance then shouldn't the splice somehow throw the resistance level off through corosion and such... I work at a shell service station as a cashier an one of the mechanics told me he figured I would end up replacing the whole engine harness because it runs off of resistance and I had to add a section of wire... thanks guys

[93Leg-c]

You might have read this thread already, but vrg3 suggested how to do the rewire from the knock sensor to the ecu: http://bbs.legacycentral.org/viewtopic. ... elded+wire

[91legacyawdturbo]

i know this problem quite as well. when i bought my car the wiring to the knock sensor was shorting out, a dealer ship wanted to replace the whole harness but they want 1700.00 just for that harness! I've gone through the whole harness and have replace the connectors, now after my tranny had blown up the knock sensor light has come up again new knock sensor but still the lights on, know im back at the same problem! good luck

[Gregmckenna]

holy F@UK these things have so much more out of limp mode... my guage still doesnt read 8.7 psi it only reads barly 7 but its steady

[QuickDrive]

I take it you got rid of your Code 22 then.

[Gregmckenna]

oh yes

[93Leg-c]

What was it that made the code 22 go away?

[Gregmckenna]

its a coaxle cable... take the mesh sheeath.... pull it back so the inner wire is sticking out covered about an inch.. splice it into the original knock sensor... take the sheath... splice a peice of wire tomit an screw it to ur firewall.... it grounds an bam that was her... now I got an 02 sensor code

[kleinkid]

I wonder if I have a similar problem. On my '91 SS, about two inches from where the connector on the knock sensor plugs into its mate, headed to the ECU, there is a cut in the insulation. You can see bare wire inside. Have already replaced the knock sensor, and the code is still there. In addition, might be related or not, can't start the car with the black connectors and green ones hooked up. What do you make of this? It has been like this for several years. Need to figure it out now.

[NuclearBacon]

Simple as can be... go to the junkyard and get a spare connector (Harness side) and cut as far back as you can. Cut around the outside of the wire and get the shield and pull it to one side, twist it into its own wire, and attach another wire (to extend it) to make it a ground....

..ground it.

Then take the inside wire, Attach it to enough wire to reach the ECU pin...and splice into it.

Plug into your Knock sensor... you're gold man.

I tried fixing the wire... i tried looking for the wire.... and its really that simple. looking up the wire type in the electrical manual and then reading about it for 5 minutes means all what is said above... its wierd.... but not as wierd as it seems.

It works Great. did it on my 87 GL-10 and my Touring Wagon. Not a CEL in sight for miles and miles:)

[kleinkid]

If I was smarter I would have done this before I put the IC in.

What harness piece are you talking about? The one attached to the knock sensor or the one it plugs into?

Also, at the ECU there is a wire for the knock sensor signal(white) B56-5, and one for knock sensor shield(black) B56-4. Are you saying splice the white one only and forget about the black one at the ECU because it is going to get grounded somewhere else?

I rarely do electrical work, so I can use some coaching. Thanks.