salimshah

Just wanted to share that one member pmed me about getting the CEL after the sensors were replaced.

There has been another thread on after replacing sensors by a dealer the CEL is back on.

Please update this thread on any findings.

Thanks

Salim

imherenow

i got knock sensor light on my es300. so i would assume similar method? but i was wondering where does the wire harness connect to that is visible when i open the hood without taking anything apart. Is it possible to see that or even the harness connection is located inside the engine too. thanks

salimshah

I would strongly suggest that you post this question in ES300 forum and reference this thread. This will keep this thread clean and you will get the right answer.

For RX you have to remove all the intake stuff to get to the harness which is less than 3ft long. The location of the connector becomes evident once you remove all the air-fuel plumbing. Can you tell or reach the connector without removing the intake-stuff ... well I could not. Maybe some one who has replaced quite a few can tell.

Salim

2KHarrier

Has anyone ever looked into splicing into the Knock Sensor wiring harness and mounting the sensor in a more accessible place? I have a 1994 300ZX, and a common DIY for the knock sensor is to remount it in a different location because of the extensive work to get at the factory location
It appears the 2 sensors are wired in series, so are they redundant or do they read separate sections of the engine?

Just wondering...

salimshah

The right people to answer the question would be the engineering team who designed the engine. Anything else would be a hack and you may get a false negative information and never know if you have a problem or the ecu may never adjust timing.

Keep in mind that the knock sensors are not a frequently serviced item. Maybe 2 or 3 times in the life time of the vehicle. People who have done it more than once claim that it can be done in less than 4 hrs. So it is not so bad.

I think there are 2 return wires, one each from a sensor in RX.

Salim

imherenow

salim, have you looked into this thread. would bypassing to the other sensor create any problems in driving or to the engine?
https://www.clublexus.com/forums/rx-...ck-repair.html

salimshah

Warning ,,, Salim getting on a soap box.

I have not commented in there as I think I am not qualified to comment. I have shared my opinion about sensor outputs in "Having problems ,, start here Mega thread".

If it works for people and they are happy, who am I to tell them not to do it. Would I do it .. No, as one of the consequence is false negative. Engineer is supposed to design the most cost effective solution and if they have 2 sensors then in their wisdom there has to be a reason. With the same token they can make mistakes too.

Ethically, I am against the hack and passing it to the next buyer as nothing is wrong. There is a strong possibility of this to be abused in second-hand market. But then again I am not going to be self appointed moral police.

Hence ... No Comment.

Salim

Cooldaddy

I agree might as well do it right the first time and ill post the part numbers as I make sure I have the right ones.

Cooldaddy

Allow me the opportunity to understand this completely. I have the knock sensor code and my OD is gone and when driving in the 3rd gear seems it shifts in and out of 3rd hard like when I let off going down a hill then when I get back into it. Shifts hard. Is that the behavior you guys are reflecting on. Hope the knock sensor replacement fixes it all like you guys say.

salimshah

It was some what strange for me ...

On the first onset the od was fine.

After few weeks the od was locked out, but would reset after I switched the ignition off

After couple of weeks, the od would only comeback with OBDII reset (disconnecting +12v would have worked too)

Salim

Cooldaddy

Ok Saturday picked rx up from shop did plugs timing belt and water pump 2 bad coil packs and got her inspected. Driving home got the knock code and a timing code. My thought is if they got the timing off one tooth then seems that error would come up. The did a diagnostic test before the inspection and supposedly fixed all know problems. I called them today and taking it back before I spend $500 in parts for what could be a out of time engine. Ill let you guys know what is found.

salimshah

Yes, get the timing thing fixed first. I dont think you will save any by preemptively doing the knock sensor fix.

Salim

uncle

What are the issues if you do this job without removing the wiper assembly? Does it make sense to remove the strut tower bar? When people remove the 14mm hidden bolt, do you approach it from the right side after the throttle body has been removed? If you do not change the cooling hose, do you still need to drain the coolant? Does coolant run thru the manifolds?

salimshah

There are more than 1 hidden bolt. The one I dread about and complained about was the one next to the engine lift hook ,,, near the firewall.

Members have claimed that they were able to get to the knock sensors without removing the wiper + cowl. Removing them increases the access, but keep in mind the firewall still limits the access to the hidden bolt.

I dont recall removing the strut bar and there is no mention of it in the DIY.


Hidden bolt: Follow the steps in the DIY. I accessed it from the front and right side (passenger side).


Yes, you need to drain the coolant, as stated in the DIY. I did not change the bypass hose.

Salim

uncle

Salim, Thanks for your help. So with the wiper assembly removed. you approached the hidden 14mm bolt from the 12 o'clock position or from 9 o'clock? I have attempted to access it from the passenger side of the car at 9 o'clock and haven't come up with the correct wrench to do so. Can you add additional comment or explanation on this bolt, and the other hidden bolt.

Has anyone used any of the aftermarket knock sensors?