gixxerpimp

maybe im an idiot but i still dont understand my code 52 knock sensor fault. 94 pickup 3.0. engine cranks and runs perfect. if you put motor in a strain or going say 45 mph in 5th gear it will throw a code 52. you can turn off and back on to clear fault and gear down to stay at a higher rpm and it wont come back on again unless you put a little strain on it. if the wire or sensor were bad wouldnt it throw the code all the time? i have changed plugs wires cap and button. put 2 tanks of 93 in it so far too. everything ive read nobody really says whether theyre having a fault all the time or just when the motors in a strain like i am having. PLEASE MAKE ME UNDERSTAND!! thanks

scope103

Remember that code 52 does NOT mean that the engine is knocking or not knocking, it means that the ECU hasn't heard from the knock sensor is a few seconds. So I don't think changing ignition components or fuel makes any difference to the code.

Since the most likely cause of a code 52 is a problem with the wiring, I think you just have the good (bad?) luck to have wiring that doesn't open up until you get the right set of vibrations. It is possible that your ignition timing is so retarded that the engine never knocks at all in the timing swings put in by the ECU, but I don't think that is really how the sensor works. Nonetheless, I would verify that your ignition timing matches the under-hood sticker.

gixxerpimp

thanks pal. i know you cant change the sensor without pulling the intake. any hope im "lucky" enough to just change the wire to it without pulling anything?

HappyAdventure

I think the pigtail that goes from the sensor to the wiring harness is what tends to go, and no, there is no way to get to it with out pulling the intake. It snakes through a little groove in the head, under the intake gasket. PITA to get to, could check your harness back to the ECU though.

FleshThorn

My experience rewiring a KS proved that the wire has to be shielded and the shield grounded. I am not sure exactly where the OE wire shield is grounded, but that connection could be loose. Just my $.02.....

shaeff

Check the link in my sig.

gixxerpimp

thanks for the advice guys. pretty sure i understand it now finally. pretty simple concept to be so damn confusing at first!! LOL. gonna order a new pigtail and sensor. im thinking ebay should be fine?

FleshThorn

They are not that much from a Toyota dealer, I am thinking around $13-$15.

shaeff

My dealer only charges about $10/ea.

3-BALL

I just went through a knock sensor problem. I put in a KS from Kragen and it still threw the code replaced it with one from the dealer no more code...I did the pigtail with the first KS so it was not that. I would definitely buy Toyota

WestCoastMoose

Well, I've been reading the threads and posts on the code 52. Weird how it happens on rebuilds, but not swaps.
I got the code today.
I just finished (Feb 6th/11) putting together a 3vze. Picked up a short block with 100,00km on it(60,00miles),put on brand new heads, ported the plenum,intake, heads and exhaust ( done myself) and the Weasy2 cams top it off . Had the valve adjustment done properly @ an engine shop( didn't want to screw up on such a precise tolerance) Actually added .002 on the #6 ex valve to allow for the later years when they tend to close up.Also added a heat shield the the crossover pipe near the problem area.
I also did the pigtail wire.The truck fired up fine and have been running it for the last week and it was absolutely awesome! During this week, I was constantly looking at the RPM's when idling, because the damn engine was so frickin quiet!!!

Sooo, question here is, if the knock sensor requires a certain frequency to work, and all is working well, will the sensor throw a code if it is not reading any "vibrations" Seriously, this engine purrs.All that is heard is the injectors clicking, and all week I was fine tuning it( air filter, timing etc.)
The code doesn't go on until after accel about 5 seconds later. To me, that means the ECU hasn't received a signal after 6 revolutions.So at idle, it feels the vibes from the cams,and no light, but when the air starts flowing and parts moving,engine running smooth, light comes on.
A short in the wire from the connector to the ECU would throw a code @ idle.The pigtail is new, and the knock sensor should not have gone in 5 days of driving.
I am pretty well versed in this truck. 2nd engine in one year. The one I just took out is a perfectly good runner I will do HG's and resell. It did not throw a code last swap....
Thanks so much guys.

sam333

The computer is looking for the signal 1200 rpm and above.

WestCoastMoose

So it is possible that the wiring from the connection the the ECU has a crack/short then.

sam333

yes its possible

WestCoastMoose

Just thinking about it, and I am sure the light is coming on well after 1200 rpms.