ECU and OBD2 not communicating

FlashPro questions & answers specific to the 2006-2011 Americas Civic Si
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ECU and OBD2 not communicating

Post by Dynue09 »

Been having issues with hondata not connecting to ecu and my obd2 scanner not being able to read codes.

As of right now I have a k24a in my fa5 everything is ready to go the car just won't start and I believe it's because it can't connect to the ecu. Cranks just fine ill check for spark and fuel this weekend.

I tested my obd2 pins and found that only pin 16 was getting power which is the power from the battery so what should I do to figure where the problem is? I was thinking of doing the FCAN circuit troubleshooting but I'm not sure that that's what my issue is.

I've double checked my wiring, all my fuses are good and even put in a new battery. I also put the ecu in another car and it connected just fine so my guess is the power is being shorted on a wire or a module.
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Re: ECU and OBD2 not communicating

Post by Spunkster »

Based on what you have said there is a wiring problem, or a blown fuse somewhere. Also check all the grounds in the engine bay.
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Re: ECU and OBD2 not communicating

Post by Jacobx_ »

Did you figure this out ?? I swapped back to k24a from k20z3 after passing state ref and my ecu won’t connect to my odb2 scanner nor will it connect to my Hondata.

everything was working before

-2008 Honda Civic si
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Re: ECU and OBD2 not communicating

Post by Jayos07FA5 »

I'm having the same issue. Did you recently change your headunit for the stereo system? I replaced my factory head unit and I think it might be related somehow. But not 100% sure. It's frustrating because I just installed some nice upgrades and the car is running a bit rough. So just wondering if you resolved the issue?
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Re: ECU and OBD2 not communicating

Post by Jackfro5t »

Any update?
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