Logo
FULL SITE MENU

Tilt trim sending unit

Garygin

Garygin

Regular Contributor
I just put a trim sending unit on today. When I hooked it up it just pegs the needle on the gage. Any suggestions on what to look for?
Thanks for your help
Honda 225
 
Hi,
I haven't worked on one but I looked it up in the service manual.
I couldn't find much other than it says to check resistance between the Light Green/Black wire and Black (ground) wire and it should be:
3.8 k ohms to 5.8 k ohms

Then check resistance between the Yellow/Blue and the Black (ground) wire and it should be:
2.7 k ohms to 4.3 k ohms.

That is the basic check to see if the sensor is good. I know it's new but lots of new parts are bad these days.

Other than that, all I can say is that the Light Green/Black wire connects to the vcc 3 terminal on the ECM and I believe that is a 5 volt signal. So, checking that terminal for 5 volts with key on to verify the operating voltage is correct might be the next step.

If that stuff checks out then maybe start looking for a possible rub through in the wire harness maybe causing a short to ground. Just guessing though.

Sorry I don't know more.

Good luck.
 
Hey jgmo!
Thanks for the info. I checked everything and it is right where it should be . Still doesn’t work. The question I have for you is , when I turn the key on and check voltage and such I’m getting continuity between the signal wire and ground at the gage. Is that right?
Thanks Gary
 
Hi Gary,

Well, I don't really know for sure.

I have never "troubleshot" one of these and have no hands on experience with the 225.

I don't understand how you're testing either.

Continuity means Ohms testing to me.

But, in this case, you're looking for volts.

Do you have 12 volts at the Black/Yellow (Bl/Y) wire at the back of the trim gauge with ignition on? The gauge, being digital, needs that voltage to "turn on" and be ready to work.

Do you have 5 volts at the VCC3 (voltage common control) terminal at the ECM? Light green/Black (Lg/Bl) wire with ignition on?

IF SO....

.....With ignition on, you should be seeing a PORTION of the 5 volt signal from the trim sender to the Yellow/Blue (Y/Bu ) wire at the trim gauge terminal.

The portion should likely be between 0.5.v to 4.5v depending on the trim sensor position and should change as the sensor angle changes. I can't give you specific voltages but that should be fairly close.

When you probe the Y/Bu wire at the gauge, put your red test lead on the wire terminal and the black lead on a reliable ground. Don't use the the Black (Bl) wire at the back of the gauge for connecting to ground because you don't know if it is reliable yet.

Make SURE the ground you choose for testing is a good one by testing for 12 volt power at another location using that ground. Many times a poor ground will invalidate your testing.

if you don't have 5 volts from ECM with Key On Engine Off (KOEO), try starting the engine and check again Key On Engine Running (KOER). Make certain that you're using a good ground!

If no 5 volts at ECM in either condition, I would have to say the ECM may be faulty. But, again, I have no experience with this and very limited service info.

If you find that you have the portion of the 5 volts signal at the trim gauge Y/Bu terminal that changes as the sender angle moves AND you have 12 volts at the Bl/Y wire then either the gauge is bad or the ground for the gauge is not a good one.

You could use a jumper wire to provide a reliable ground for the gauge to see if that's the problem.

I hope this is understandable to you....
...if not, my apologies.
But, I'm sorta wingin' it using my phone and a free pdf service manual wire diagram which is fairly difficult to read.

But always happy to discuss the issue and answer questions.

Let me know what.you find.

Good luck.
 
Hi jgmo.
Well I did everything you suggested. It all checked out perfectly. I do have a service manual, but I can tell you , you were more of a help than the manual. After I checked everything I decided to call Auto Meter and ask them what they thought. Long story short they said that the gauge works off of ohms, not volts. So that’s why when the gauge is energized it pegs the needle.
Thanks again for all of your help. I would still be trying to figure it out.
Best, Gary
 
Back
Top