I have this swap in my 94 civic hatch and it runs and drives great. some smoke in vtec but thats not my issue. My issue is the check engine light comes on almost every time I drive it. doesn't matter if im beating on it of driving it easy, same 2 codes everytime. code 6 (coolant temp sensor) and code 23 (knock sensor). both codes are set at the same time everytime. I replaced the coolant temp sensor and it didn't change it at all. please advise if possible, thanks

 

somebody please advise, I don't know whats causing this and really want it cleared up. would a bad knock sensor cause the check engine light to come on for the coolant temp code?

 

please help

 

You literally just posted it. People aren't just sitting here waiting to reply to your posts.

Onto your situation is your car overheating or anything when your CEl pops up for ECT? Have you checked your wiring?

 

no overheating and I didn't chase all the wires but did check for obvious problems with the wires at the sensors and the ecu and everything looks good. If I only had one code set it would be a lot easier to find the problem. just confused why both codes set everytime, not just one

 

Lol 2:01 2:02 2:09 very anxious. If both are coming in at the same time, I would normally say check what they have in common. However, the knock sensor is a single wire that works on piezoelectric effect of a crystal being compressed, and has no common wires/connections. Iirc. So the knock may be caused by actually having knock because of fuel issues stemming from the ect sensor issue. I would check for 5v and ground @ the ect sensor connector first. Either that or you have the connectors swapped because I think they have the same connector shape.

 

in his defence this was poted last night lol see the date just bad timing when he bumped it

 

Sorry, been drinking, and the troubleshooting school I'm in makes me feel pokey.

 

You literally just posted it. People aren't just sitting here waiting to reply to your posts.

 

Oh ok yea, that's perfectly bad timing.

 

it has a new coolant temp sensor. same problem with new or old sensor.

 

can you try another ECU ?

 

Yea, I have another p72 in my db8 I can try. I'll do that tonight and advise in the morning.

 

Little update here, I was able to unplug the knock sensor and it started right up and the check engine light is not on at the moment. I would figure it would kick on right away with the sensor unplugged. does this mean anything?

 

I didn't get a chance last night to try the other p72 that I have but I still have the knock sensor unplugged and the light has yet to come on. does this mean anything?

 

The knock sensor and ect may be shorted together in the ecu. I don't have ecu schematics (wish I did) but the fact they don't connect anywhere but in the ecu leads me to believe its inside. If the 5v and knock sensor shorted together the knock would always see voltage causing it to be wrong and the resistor circuit for the temp sensor to see a resistance that's out of range. If you can swap ecus go for it.

 

I still have the same story. I haven't switch ecus yet because the light still hasn't come back on again. every since I unplugged the knock sensor I haven't seen the check engine light come on again. and hows your awd teg going?

 

Slow and steady as always. I'm in maintenance school so I only get weekends to work on it, but at least now I get 2 day weekends.

 

the knock sensor is still unplugged and the light finally came back on

 

Is it still for temp sensor? I'd check the wires for continuity from sensor to ecu. Although I remember a lot of sensors sharing a green wire with white stripe that goes to ground. Do some wire checks and if that comes out fine, swap those ecus

 

temp and knock sensor. I need to take my head out of my *** and swap those ecus, just crazy busy all the time here.

 

If this is in a civic what harness did you use? Was knock wired in correctly?

 

Maybe you can use these to help you. I love em. I keep them on my phone.

 

Ok I noticed the second one isn't a fill pic, if you think something like that might help, I can see if I can scrounge up the full drawing. But its in a locked pdf so I'd have to send you the full manual. Its worth it if you don't have a manual.