Knock sensor wiring issue

mpg

New member
Greetings,

I'm in need of help in figuring out out how to get the wiring right for the knock sensor, 88 ST-165, please.
The CEL shows code 52, I clear it by disconnecting the power - When the car is started, all is well, the CEL stays off until I press the gas and about 1400RPM it comes back on, stop the engine, short T-E1,check, and code 52 is back.
The knock sensor was replaced with a new one,the code was present with the old one. and wiring to it looks like crap. It has one black wire stuck firmly into it, a splice with what look like a secure plastic housed crimp connection, and about 2 inches of exposed stranded wire (exposed after I took the electrical tape off it). There is a 1/8 inch bit of braided wire sheath hanging that I thought is supposed to be the ground? I have no idea what the connection off the plastic plug is supposed to look like. I did a continuity check at the plug end that goes into the knock sensor and back to the KNK terminal (with the wiring block removed from the ECU) and it is good. I was told that what is needed to be replaced is the wire with RG-58A/U coax braided cable and run the outer braid to ground, inner to the sensor. Your help as always is greatly appreciated.
 

Anoo21

New member
Hey I meant to get back on this because I had the same problem new sensor and I replaced the wire directly from the ecu to the sensor. Used just a regular cable"rg" wire, the copper wire directly to the sensor and the shield was to ground. I will see if I can get my pictures back up, i thought it might be in my build thread. Good luck, I was very very happy once I fixed the problem.
 

underscore

Well-known member
That wiring sounds pretty roughed up, and the knock system on these engines tends to be very picky (bad motor mounts have been known to cause knock codes). I'd suggest replacing it with properly shielded wire and go from there.
 

mpg

New member
I got the RG 58 wire in the mail today, found it for $1.20 per 3 feet on ebay it looks good quality and same gauge inner wire as what little is left from the original, going to run a length direct from the sensor to the wire block on the ecu plug as you mentioned to make sure it's good, but may need to go with a high temp lead.
It's just a really hard to reach fix, can't go in from the top, and the hole on the passenger side front with the wheel removed gives me 1 hand with a view or 2 hands blind, with the car on jackstands.
I'll let you know how it goes, you guys/gals are the best!
 
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