code 52 knock sensor

[red90turbo]

I recently rebuilt my 7mgte with a new turbo, head gasket, water pump the whole shabang and i wasnt getting boost after i let the engine break in, went ahead and checked the check engine light and it came up code 52 knock sensor, could that be why im not getting boost?

 

[hvyman]

Yes. You need to fix that asap.

 

[Whosoever]

I had a broken connector on the KS closest to the starter and that prevented boost for me. Replaced it and I was a happy man!

 

[mk3_7m]

Yes, the ecu is playing safe and has the engine de tuned. Make sure you didn't mix the grey plug sensors with a pre yellow plug loom or vice versa. Thats what gave me code 52.
Now it's back again after a few years might be that the sensor is just too old now.. or might have to check my wiring.

 

[OfnaRcR4]

99 percent of the time its wiring. Search "knock sensor rewire" and you'll find pleanty of threads on how to do so and what's going on. Common problem on supras.

 

[red90turbo]

how long does it take to rewire the knock sensors, and should i just get the knock sensors to avoid taking the intake manifold off again because ive taken it off 4 or 5 times cause of the fuel rail o-rings

 

[OfnaRcR4]

http://oldschool.supracentral.com/htm/knock.htm#rewire
http://www.toyotanation.com/forum/showthread.php?t=280210
http://www.duanesmith.net/87tknknew.html
more spoonfeeding

 

[CajunKenny]

My car threw a 52 because of the forward most KS getting soaked with oil from a leak. Not that your problem is this, I'm just throwing out another experience...

 

[JNasty]

ive read all these rewire write ups and i still dont get it! do you wire both knock sensors to one coax cable or is it two individual coax cables that you run from each KS to the ecu because in the pictures it looks like one coax with each KS spliced into it? and do you run the coax all the way into the sensor or splice it in to a regular wire that goes into the sensor..

 

[Wayne G.]

There is a seperate wire for each sensor that runs to the ECU. And yes the coax runs all the way to the sensor plug that goes on the sensor. As several have stated the knock sensors rarely go bad it is usually the wire. The factory only grounds the shielding at the ECU however, one write up says to ground both ends. Stick with what Toyota does and only ground one end (ECU).

 

[JNasty]

i got a shielded wire it has a blue wire,white wire, and a bare wire inside it i know the colored wires run to the sensors and the bare runs as a ground ( all on the block side ) but im confused as to where they run on the ecu side ... i know that they splice into the harness wires but what i need to know is do i remove the old wires from the harness and run these new ones into the harness or just splice them into the old wires. and where do i run the bare wire cause if i ground both ends of it then that is defeating the purpose..and also would cause "ground loop" wouldnt it? one more thing does it matter witch sensor wire runs to witch port in the ecu?

 

[mk3_7m]

It might tell you in there.

http://oldschool.supracentral.com/htm/knock.htm#rewire