23 CEL - Knock Sensor - Honda Prelude Forum

akio74 · 07-31-2005, 03:15 PM

I had the p28 ecu which did not utilize the factory knock sensor, so my mechanic had "disabled" it. Now I have put the stock ecu back in and am getting CEL 23 for knock sensor. I'm sure it's because it was "disabled" but when I checked all the connections to it, everything seems to be in tact.

How else can the knock sensor be disabled?

sharkcohen · 07-31-2005, 04:07 PM

You're going to have to find out what exactly your mechanic did to your knock sensor. Considering the p28 doesn't know anything about the knock sensor, I'm not sure why he would have done anything to it. Sounds like you may now need a new one, though.

akio74 · 07-31-2005, 06:02 PM

shark - ive been reading that CEL 23 - knock sensor isnt the problem code throw from reading knock, but rather a circut problem with the knock sensor, or damaged unit. is this correct?

however this thread...http://preludeonline.com/showthread....ghlight=cel+23, speaks about several resolutions to a cel 23, most of which diagnose problems causing knock.

im confused, does the cel 23 tell you are getting shock knock or a problem with the unit's circuit?

sharkcohen · 07-31-2005, 06:20 PM

It means there is a problem with the sensor, the wiring, or the ECU, not that there has been knock.

akio74 · 07-31-2005, 06:49 PM

thx shark, im also throwing abs code 81 - ecu.

im going to start there w/a known good ecu tomorrow. ill let you know what happens.

blk97ludeSH · 08-01-2005, 10:29 AM

^^ hey tyson did you get everything you needed for ur car?