I am trying to set up a k20 conversion harness for an 01 I sight. I've done cluster swap for it and based on the diagram coolant temp signal is a4 @ cluster. light green wire. I assumed it was on the engine harness that provided signal through the chassis connection. but I guess I was wrong and forgot to grab that plug from a wrecked insight. I have the complete engine barness so I was able to trace it all out.

but I can't find the coolant temp signal from ecu to cluster. I have the rest pretty much figured out.

 

On my swap an 04 TSX engine the engine coolant temp is on the CAN bus between cluster and ECU.

I am not certain but I think most of the K stuff the temp is on CAN bus.

So you could convert CAN bus to a voltage with something like Arduino or install another temp senor in the head for the cluster to read.

For the real advanced the 06+ S2000 cluster gets its coolant temp from a serial interface between ECU and cluster.

 

my rdx is the same but the temp fees comes direct to cluster. if there was a comm wire to the mcu (multuplexer) then yes. but here it's direct connected to the cluster.
I tried joining insightcentral.com but can't for some reason. I will recheck the shop manual tonight, hopefully I missed something easy.

 

I found it. was able to source out the ecu pinouts and full service/shop manuals.

you

 

Don't bother, they don't know what a K series is and they will ridicule you for not getting 70mpg.

Glad you got it sorted. You should post up what the engine came from and what pin is missing to help the next guy out.

 

mianly wanted to join because in a search it said the service manual was stickied. lol