The set-up:
1998 EK4 (Civic Sedan)
JDM B18C 98, Spec ITR
JDM 98 Spec P73 ECU

here is the situation. for the longest time i have been using a P28 chipped ECU with a Spoon Program from Japan. recently i decided to use my JDM 98 ITR ECU for better fuel economy, and just to run it on the Autobahn.

I plug it in, let the car idle and adjust to the new ECU. well i start to drive the car and before i even get to the end of my street the check engine light comes on. so i am like WTF?!?!

pull the code and find out that its a knock sensor code. how can that be when JDM ECU's dont look for knock.? well i put a brand new OEM knock sensor in, reset the ecu, and wait. start the car and the same thing happens. check engine light and knock sensor again.

anyone have any info or ideas on what this could be?

thanks in advance.

 

JDM ecu do look for Knock, did you run the wire for the knock all the way to the ECU, I am not sure of the pin location for OBD2 but for obd1 it would be D3 on the ecu plug

 

List the actual code.

 

damn guess I was wrong. feel like a clown now. did some looking around and was told on several occasions the JDM versions didn't look for knock. " palm to my fore head "

 

I was under that assumption as well, which is why I thought the code might not actually be for the knock sensor.

 

yeah that my help actually.

CEL 23

I have already checked for continuity and it checks out. I am actually using a modified 98 CTR RHD engine harness as well, so everything plugs in no problems.

 

double check and make sure you have it in the right spot looks like it changed between obd2a and obd2b

obd2a pin outs
http://technet.ff-squad.com/wiring.obd2a.htm

obd2b
http://www.ff-squad.com/tech/wiring/wiring.99-01.jpg

i think in jdm land they are a year ahead of us in the USA at least


PS I have a JDM p30 and know for sure it looks for knock

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/autozone-duralast-knock-sensor-3187875/

still no code 23 on mine since replacing the sensor

 

I think in obd2 format they did start having the knock sensor, the p2j ecu for the d15b 3 stage vtec actually has the input for one. Plus the engine itself has the knock sensor. Maybe the obd2b format and not the obd2a.

 

with the harness and ecu both 98 its most definitely obd2a. checked the lines and pin outs again and it checks out as the right slot. the only modifying I have done was removing the loom for more space.

like I said its weird. I always use 93 Octane or above here in Germany as its readily available everywhere. so I shouldn't have any issues with how the fuel burns.

 

I don't believe the knock cel will come on if it detects knock, I think the ecu will just pull the timing.

also you may try running a new wire from the ecu to the sensor to test

when I removed my knock sensor wire from my JDM harness to add to my USDM z6 harness, the knock wire was shielded from the sensor for about 3 feet the shielding was tied into another ground then then the unshielded wire was run to the shock tower then to the ecu, also check the plug on the harness that connects to the sensor for corrosion and make sure the sensor is tight to the block because thats where it get the ground from.

If possible test with another ECU if you know for sure the wiring is good

 

i actually checked the plug the other day to make sure it was good. no corrosion or damage. i know my timing is good cause i had my water pump and timing belt done by Honda this past April after i got back from Afghanistan.

unfortunately i don't have another ECU to check this with. i do have a D16Y8, but that's no good to me.

i did tighten down to the OEM specs as well, 23ft lbs., or am i supposed to go tighter or loosen this bad boy up?

thanks for all the help so far

 

Did you test the knock sensor?

 

did all the appropriate steps for troubleshooting the knock sensor. apparently I need to swap out ecus and test that as a last resort. if all else really fails its to the dealership

 

if the wiring checks out, then all that is left is the ecu and the sensor.

when i installed mine, I hand tightened it then snugged it up with a wrench, didnt use a torque wrench, might be worth taking it out and then reinstall.

the failed knock sensor I had the plastic part of the sensor was loose and would move, the replacement had no movement at all

I don't know what else it could be

keep us posted

 

thanks for the heads up. I am going to get an alignment today. so I will loosen it up, reset the ecu, and keep my fingers crossed.

 

well I got my alignment done and the 1st thing the Technician noticed was the check engine light on. so we discussed it in German/English and checked it out.

had him loosen up the knock sensor and we pretty much put it back in hand tight, pretty much similar to the oil filter tightness. reset the ecu and once again followed the steps in the Honda shop manual.

check engine light popped back on before even getting to the main street. so now I am going to hunt down another JDM P73 or JDM OBD2 CTR or SiR ecu and try that out.

 

So im understanding you took out the knock sensor, then put it back in and got the same code??

 

yes. that is correct. so now I am wondering if my ignition timing may be off.