2003 Z150TRLB ECM Main Relay Issue

[99yam40]

you just need to find the proper people that know what is required to make this system work properly.
Boscoe has already asked if the ground is being provided for the main relay when the Key is turned to the on position( Blue/yellow wire).

I would check at the relay and back at the ECM to see
need to make sure there is not a bad connection or wire

do not start chasing rabbits down holes others send you to.

Rodbolt is a Yamaha master tech, and Boscoe is the master of finding info on these things.
do what they ask

[Mr. Nice Guy]

I have a feeling he is thinking of a different motor ignition system, but since it will crank, fire, and run by bypassing the relay, you need to find out why that ECM is not providing the ground to pick up that relay

I agree! There must be a reason (perhaps the ECM is trash,... but my understanding is that is very rare)

[99yam40]

not all outboards use a charge coil and a CDI ignition system which you are describing

[rejesterd]

I have 4 relays - tried them all (in various iterations)

I'm not 100% certain on the process to test the ECM and Pulser coil peak voltage - is there a write up somewhere that explains it?

I'm surprised it's not in your service manual, but it's a very common test like I described earlier. It's the same basic test for all modern engines. The manual should at least give you the specs for output peak voltage when cranking. There's usually a whole section on just specifications. I don't have your manual, so I don't know what the values are. But a peak voltage test is a universal thing.. not specific to any Yamaha model.

[99yam40]

I have a feeling he is thinking of a different motor ignition system, \

but since it will crank, fire, and run by bypassing the relay, you need to find out why that ECM is not providing the ground to pick up that relay

[Mr. Nice Guy]

If it starts and stays running when you bypass the relay, then I wouldn't bother with the starting fluid.

How many relays have you tried? Just the one? I've bought bad relays before. I would try at least 2 if you haven't. Then if it still doesn't work, test the ECM & pulser coil peak voltage.

I have 4 relays - tried them all (in various iterations)

I'm not 100% certain on the process to test the ECM and Pulser coil peak voltage - is there a write up somewhere that explains it?

[rejesterd]

If it starts and stays running when you bypass the relay, then I wouldn't bother with the starting fluid.

How many relays have you tried? Just the one? I've bought bad relays before. I would try at least 2 if you haven't. Then if it still doesn't work, test the ECM & pulser coil peak voltage.

[Mr. Nice Guy]

So you have an unmounted 2003 Z150TLRB that would start and run if the relay was bypassed. So you replaced the relay along with the entire fuse block, and now it will crank but not start. The original owner also said it could start and run if starting fluid is sprayed into the air intake. (Hoping this is all correct)

All correct (sorry, I know the info wasn't quite clear... my fault)
I haven't tried spraying starter fluid for start - but, I can give it a try if it helps diagnosing.

So if you bypass the relay now, does it stay running?

Yes, engine will start and run smoothly if I jumper the relay. (but, I don't know how it will run under load)

[rejesterd]

I went back and re-read your posts on this thread, as the info kinda trickled down slowly (not criticizing you, it's just how these threads go sometimes).

So you have an unmounted 2003 Z150TLRB that would start and run if the relay was bypassed. So you replaced the relay along with the entire fuse block, and now it will crank but not start. The original owner also said it could start and run if starting fluid is sprayed into the air intake. (Hoping this is all correct)

If it's never been mounted (or was mounted for a very short time and taken off), then I would believe the 25 hour reading you got from YDS. The reason I suspected the ECM is because 25 is extremely low for a 2003.

The injectors will start operating before the main relay is actuated to prevent them from sticking.. so that's why you're hearing the clicking even with the main relay removed.

So if you bypass the relay now, does it stay running?

[Mr. Nice Guy]

I am guessing your red meter lead was used to prob those spots, but I am not sure where you landed the black meter lead.

Tested alternating ground/hot leads to and from battery ground vs positive.

[Mr. Nice Guy]

Also, I meant test the relay itself, not the connection points in the fuse box.

Yes, both relays have been tested as good.

[rejesterd]

Ok, so we don't know if it's running perfectly under load or not. We just know it runs.

Get a peak voltage adapter for your multimeter (or buy a multimeter that comes with one). You hook it up to the ignition coil wires and and crank the engine. The manual should have specs for the voltage when cranking and at other running speeds. If it's too low, it's probably damaged. But you also should measure it at the pulser coil coupler as well to see if it's too high. That would require a special adapter from a dealer or you'll have to get creative and make one on your own. Again, the manual should show the wiring for it.

Also, I meant test the relay itself, not the connection points in the fuse box.

[99yam40]

I am guessing your red meter lead was used to prob those spots, but I am not sure where you landed the black meter lead.

And this was with the key in the on position

Boscoe99 shows a #9 to check for ground , but your numbers are not even close to what his print shows for some reason

[Mr. Nice Guy]

Another interesting note, if I pull the relay out and turn the key... the Injector Driver Relay (right next to the ECM relay) makes an audible click (closes). When the ECM Relay is in place - the Injector Driver Relay closes no matter if the key is turned or not.

[Mr. Nice Guy]

I tested each of the relay connections - the results are as follows:
30 = ground measured 12.69v
87 = Hot 12.69v
85 = Hot 12.69v
86 = Ground 8.18v

Haven't run the motor under load (as it's not currently mounted on a boat)