Hey everyone. I just purchased a 97' EK hatch and have a question to ask, but I figured I would intro here first (2 pics at the end, more pictures after back from some "touch-ups").

I bought the car to do some of the GRIDLIFE events here in the mid-west. It has seen a few autocross events several years ago and then sat for a while in a garage. 79K miles on the chassis. NO rust anywhere, except a small spot of bubbles where the back passenger fender meets the bumper that is being cut out and replaced as I write this.

It is running an F20B with it's matching T2T4 LSD trans and OBD2B ECU. The previous owner did the swap and the wiring, and the car runs very strong. The wiring is where I think I have an issue. Onto my question;

My speedometer does not work. I have done all of the troubleshooting and have determined it is an open in the signal wire to the speedo (blue/white). Based on wiring diagrams, I should have continuity between the VSS connector signal wire (blue/white), pin 5 if (I remember correctly) on the B connector for the instrument cluster and the VSS input on the ECU (Connector C, pin 23 in this case).

I do have continuity from VSS signal on VSS connector to VSS input on ECU. VTEC works and no CELs. I do not have continuity from the speedo signal wire (blue/white pin 5) to either the VSS connector or the ECU. I have traced the existing wiring, but the swap has modified some of it and I cannot find the junction point/split. I assume it was rewired during the swap (not converted to OBD1, is full OBD2B with matching ECU).

So really... 1.) Where would the signal wire from the VSS split and go their separate ways (ECU and speedometer) for a stock Civic CX with a d16y7?
and 2.) Am I better of just saying "screw it" and tapping in near the ECU and running a new signal wire to the cluster?

Thanks! OH.. and yes, I did try a new VSS and two clusters just for fun (staying with a CRV cluster now actually). I also have the appropriate voltages and signal when testing at the VSS connector.

-=Mike G.

 

Since you truly have no idea how the entire chassis was wired, running a wire from the VSS input location at the ECU over to the blue/white wire at the gauge cluster solves your current issue.

 

It comes through the firewall from the VSS and into C130, the brown power/ground distribution connector near the grommet on the cabin side. From there it splits, one wire goes to the ecu and the other should go to C131 (the green connector near the ecu) pin 18. If you have a blue/white wire on the cabin side of that connector but not on the engine side, you've found your culprit, but being that the PO rewired the car there's not guarantee of anything.

 

It goes into a brown dead connector that splits the signal to the ecu and to the dash. So its inside the cabin under the glove box just before the main harness goes into the rubber boot to come out in the engine bay under the battery

 

Also the connector at the sensor always breaks. My issue was the connector broke and I got a new plug and messed up the order of the wires going into the connector at the sensor. Finally figured it out by testing continuity from the ecu blue white wire to the sensor blue white wire

 

That's a good point actually. Quick check is to see if the ecu is reading speed or not, easily confirmable in your ecu data. But you should also get a code 17 pretty quickly if the ecu isn't getting signal. My $$ is on a missing connection at C131

 

This is what I was looking for... where it splits.

I have continuity between the ECU and VSS. I wanted to find where it split and see if I have continuity there at all. This will tell me if the PO completely bypassed it, or something is just old/broken.

BTW.. I wait a few days, come back.. and BOOM lots of info and response! THanks everyone! The car has been at the body shop since last week. As soon as I get it back I will check this out and update here.

Thanks again, and more to come. Trying to get the car 100% for my first track drive ever... the October, GRIDLIFE event at Gingerman (HPDE beginner).

-=Mike G.

 

Good idea! I assume the OBD port works... lol This car was OBD2A, but it's got full OBD2B everything in it (ECU, dist, intake mani, etc.).

VTEC does work, and no CEL. I just don't know if this ECU allows VTEC without VSS or not (37820-PCB-004).

 

It's rare for someone to completely convert a car running obd2a to obd2b. I would check the wiring at the ecu.