new knock sensor, still code 52

[Turbo Goose]

Hi guys, fitted a new knock sensor and still getting code 52. Low resistance in cable between knock sensor and ecu

Cheers guys

[JayJ]

Did you replace it with OEM Toyota sensor?

[Turbo Goose]

Yup and im £160 lighter for it, rip off bastards

[mikey4410]

Will just be damaged cable/sheild.

had the same thing with mine before a few times.just got hold of sheilded cable did the repair and problem solved no probs.

also repaired a friends knock sensor wire and went perfect also

[Turbo Goose]

Its got a block connector half way down so presume the shield and inner have been shorted out ( not my doing)

[JayJ]

Put in a completely new wire without any extra connectors :-)

[Turbo Goose]

Might be a misson doin the end at the plug into the ecu, theyre tiny crimp connectors

[daniel_g]

Check the wire for continuity, if its all good then solder the joins and insulate it.

[mikey4410]

Theres absolutely no need to go anywere near the ecus wiring.

there should be NO extra connectors whatsover, and u can replicate ure own sheilding by using copper wire wrapped round multiple times whilst at the same time being SOLDERED to complete the sheilding earth circuit.

[Turbo Goose]

Does the knock sensor wire not go straight to the plug that goes into the ecu?

[mikey4410]

The knock sensor wire goes to the ecu yes.it has a sheilded outer thats earthed somewere down the line.

[Turbo Goose]

Right, so i have to take the pin out of the ecu to solder a new wire to it. Ive got sum shielded cable from work ready

[Turbo Goose]

The ecu plug i mean

[mikey4410]

No !!! U NEED to source the issue, which in ure case is a connector added in were it shouldnt be from what ure saying. Fix that piece.

Doin it your way is a BIG painfull job and needless.

[Dean_mc88]

I had this same issue new wire and new knock sensor but still code 52 after reading this it needs to be earthed? I asked a lot of people who said it doesn't ?

mikey be nice to get a little run down on running a new wire or fixing the earth etc if you could

Edited July 9, 2014 by Dean_mc88

[mikey4410]

The earthing/sheilding around a knock sensor on a starlet IS ABSOLUTELY IMPERATIVE i assure you.

whoever says differently hasnt a clue what they are on about.

the shielding stops interference/tapping or vibration of the wire going to the ecu and giving an error (ie making the ecu think knocks happening constantly)

I promise you I have been through all this agro with knock sensors as I said and I have repaired not only my issue but somebody else's when nobody could figure it out.

Edited July 9, 2014 by mikey4410

[_shaun_]

Surely its earthed via being bolted to the block?

[Dean_mc88]

cheers mate very helpful I have bought a complete new loom so I hope that sorts the issue as it has the original wire for the knock sensor

[mikey4410]

Wether its bolted to the block or the boot or the exhaust it still needs continuity along its whole sheilded length lol

[Turbo Goose]

Cheers mikey really helpful ill get on it see what i can do

[Stu]

As said above, the signal wire from the knock sensor must be completely shielded from just before the plug on the engine all the way through to about 100mm from the ecu where the shielding is earthed to signal ground from the ecu. If you have any joins etc then that will not be helping. The shielding should only be grounded at the ecu end where it runs to the signal ground pin on the ecu. I've fixed this issue on quite a few starlets and its always been a fault with the shielding in the section from the injector wiring covers to the knock sensor so there should be no reason to pull the whole loom out to replace the whole wire unless your really unlucky

Also take note the shielding is also grounded to the oxygen sensor shielding (again SIGNAL GROUND) so it pays to make sure its not grounding to the gearbox as again it should only be grounding at the ecu end

[Turbo Goose]

Sorted, the center wire wasnt even connected! It was about 100mm down the inside of the screen.

[Stu]

Awesome! Sometimes it can take a ecu reset to make the code go away but sounds like your all go!

[_shaun_]

see am getting error 52 aswell but its only when the engines reved am assume thats pointing to be actually knocking? as id assume a broken wire would just give me the code all the time

[Turbo Goose]

Think knoch sensor only works past 3k. Reckon i read that sonewhere

Mine wasnt connected at all and i only got lighy past 3k. So urs will probs be wiring as well