B18C4 - HONDATA S300 V3 - Pin A4 Floating Current

[MiniMojo]

Whilst testing to try and get my VTEC to engage I noticed that Pin A4 of the ECU (VTS - VTEC Solenoid) has a constant 12V reading with a multimeter. However, this isn't a true 12V as it won't light a test bulb. I believe it's called a floating current. (Tested with ignition on)

is this normal?

if not, what could be causing it?

Any help would be appreciated.

[Spunkster]

Ignoring the reading and test light what is the issue you are having?

[MiniMojo]

Hi.
VTEC not engaging.
I've bench tested solenoid and can hear it clicking.
I've tested wiring continuity.
I've got good oil pressure.
ECU has been tested and had a few bits replaced.
I've borrowed a second ECU and same result. No VTEC.
I've tried jumping pin A4 & D6.
I've run out of ideas.

[Spunkster]

I would recommend that you try the ECU on a known working vehicle as it sounds like there could be a wiring or mechanical issue on this vehicle.

[MiniMojo]

ECU tested on another car.
ECU not the issue.
I'd still like to know if anyone else gets a voltage reading from Pin A4.
I'd assume that there should be no voltage unless the vtec is trying to engage.

If there's not supposed to be a voltage I wonder if I have an earth issue?

[Hondata]

Without a load then the output transistor might show 12V. It also could be the internal circuit which checks the A4 output. Either way don't place any value on the result of using a high impedance multimeter to measure the output.

If the ECU works in another vehicle, then a ground in your vehicle would be a good place to start looking.

[MiniMojo]

Update.
VTEC now works!
Minimum Throttle was set too high at 40%, turned it down to 5% to test and now it kicks in!