Hi folks, as with all things on this car, you fix one thing and another thing pops up! Still not used to it after 26 years of ownership.

Was doing some data logging today and realized that I'm not getting any speed information from my Power FC. I definitely used to. The main gauge cluster displays correctly. I am getting RPM, temps, etc... to the FC Commander. The speed reads 0 km/h the whole time. I tried to research this and very little came up specifically troubleshooting this, other than to "look at the connections" on the main plug going into the Power FC.

Does anyone have a pin diagram, or possibly some additional information to point me towards where I might trouble shoot this. Looking like it's on the ECU side of things.

Sorry that I can't provide much more info than that at the moment. Appreciate the help!

Stephen

 

Speed is input to the cluster and then output to the ecu. Theres some magic that happens in the speedo that converts the signal for the ecu to understand. Your issue may not necessarily be an ecu one. It could be a speedo issue. Although it works correctly, it may not be outputting correctly. Worth a check at least before you start going crazy looking for stuff.

In the fsm, there is some information on what you should be looking for. It would be in the section where it outlines what each individual pin on the ecu is looking for. The wiring diagram also shows what's going on between the speedo and ecu.

 

Is your instrument cluster having any other issues? You could be getting due for a rebuild on the cluster.

Dale

 

Appreciate the responses. I have had some intermittent issues with the cluster. For a while it was the RPMs dropping out, but that's been stable for quite some time. The speedo was flaking out last summer, but that suddenly coincided with some full on electrical issues that I was able to resolve with a new battery and new alternator. I just got the car "fully" on the road after replacing my coolant temp sensor (ECU side)... fun times there. Speedometer on the gauge cluster works consistently, and only just now noticed that I don't have Speed reading on the PowerFC - I typically only display a few key measurements.

Out of curiosity @Dale, when you say "Rebuild on the cluster". Is this a DIY or can you recommend someone who does this? I do have an extra one that I stopped using a while ago because the RPMs crapped out.

Thanks!

 

Michael Gagne is the man on this - you can find him on the Facebook RX-7 group, he mainly works through FB Messenger. He has fixed hundreds of clusters and has a full on test rig to verify everything. He will also not only fix any issues but fix all the problem spots - new capacitors, etc. - so you won't run into problems down the road. I've had my cluster done by him and had friend's clusters done, top notch work and super fast turnaround.

All the clusters have kinda crap 90s electronics in them and they WILL fail at some point.

Dale

 

Thanks Dale!