Hondata

Hi everyone. Im having a strange problem with my ECU going into protection mode when ever VTEC switches on. Im trying to dial in the VTEC table but can never get it switched without the ecu cutting or entering lean protection. I have attached my calibration and datalog of the event. Thank you.

Check the engine grounds. It sounds like it is grounding through the solenoid.

Thanks for your response. I cleaned and sanded the ground at the t-stat. Car feels more responsive but unfortunately the vtec problem is still present. Is there any way I can trigger vtec output and check for problems?

Post pictures of all your engine grounds.

All grounds

The ground at the transmission looks to be rusty and may be bad.

The ground at the valve cover is not doing anything as the valve cover is rubber isolated and should not be attached to the alternator bracket.

I haven’t gotten around to the grounding situation as you mentioned because I don’t use the Honda during the week. But I did tinker around and saw this because you mentioned shorting to ground. These two copper wires were a lot closer when I discovered them. I’m going to replace the pigtail and report back for the ones in the future that may come across this issue.

ok, so I wire wheeled all the grounds, and replaced the VTEC switch pigtail connector and no dice. I've replaced both gaskets (with the screen), filled my engine oil to the top dot. I've tried both closed and open loop (if that matters)--no fix, engine still bogs when VTEC tries to engage. With VTEC off the engine will rev all the way to 8k no problems. Any advice would gladly be considered.

Try the ECU on a known working vehicle and see if the problem follows the ECU or is specific to your vehicle.

Ok so I swapped ecu and vtec worked. I removed my ecu’s top cover and found RM10 might be faulty. Is RM10 a component for vtec operation? I have donor boards to replace this component. Is it worth a shot? The zoomed in picture makes it look a lot worst than in person.

I do not know what that is for. You can try it and see.