Something I found. Car in a 94 EX. It has been throwing a code 22 intermittently. I could clear the code and it would come back. Finally it would not clear. I replaced the VTEC with a very clean one from an Acura CL but that did not help. I read online that it could be a bad ECU and saw pics posted of how they go bad. But finally when checking it again last night I found that the wire to the solenoid had broken at the connector between the wiring harness and the solenoid. This is the point where the wire flexes the most. The strands inside the wire were gradually broken until finally there was no contact. A piece of insulation was all that was connecting the two and I could tell that the two wires had been arcing. The insulation was strong enough so that I could take the plug apart and still not notice the damage. I didn't test the wire continuity with a light, but if I had, chances are the broken parts of the wire would have touched and would have looked OK. Anyway, I made a temporary connection and it works as it is supposed to. Just something to think about when checking error codes. And I almost ordered a rebuilt ECU for no reason.

 

Yeop, that's why before purchasing parts it is always best to back probe and check the connections to verify that the ECM itself is 'seeing' the signal.
Bad connectivity is usually the problem, especially with older vehicles.

Verify that the VTEC wire is correctly supported and not looped around or has excessive tension. If the loom has been opened/modified, it is always best to retape and loom the harness. Letting the wires float in space will accelerate degradation.

 

The car just had a transmission replaced and the mechanic probably disconnected some of the wiring to make it easier to get to the bolts. Of may have damaged it when removing the trans. But the wires were old and brittle so this sort of damage is to be expected. Not their fault. I had just replaced the VTEC thinking that was the problem and still didn't notice the failing wire. But as far as the cost of the VTEC unit, I got one at half normal price from the pick-and-pull (around $10) from a clean Acura CL with a lot less miles on it. And fresh gaskets from Honda and clean screens in the unit. So not a problem.