dirt im sorry for not being totally detailed. thank you so much for your time. yes i do have 12v on both black wires on fuel relay. just did (5.00 a.m.) total test, here are the results. without the ecu connected key on stop switch on (red) stop relay 4 wires 2 r/w, 1 bl, 1 b/w, fat red 12.1 v, small red 0.6 v, bl/w 12.1, bl 11.7 , fuel cut relay 4 wires,, 2 bl/w, 1 br, 1 br/w, br to fuel pump 0, br/b 12v, 2 bl 12v . now w/ key off stop switch off stop relay fat r/w 12.7 v, small r/w 0 v, b/w ground, b 0 v fuel pump relay br ground (guess from fuel pump cause it is grounded) br/b ground, both black/ground. now with ecu hooked up and key on and stop switch on, stop relay fat red 12.6v,small r/w 0.6v, 2 bl 12v. fuel cut relay fat brown 0v shows ground(from fuel pump?) br/b 11.2v, 2-bl 12v.!!!!!!!! hope this totally describes everything i am stumped studied wiring diagram 100 times and checked everything. HELP thanks

 

without the ecu connected key on stop switch on (red)

stop relay 4 wires 2 r/w, 1 bl, 1 b/w

fat red 12.1 v, Normal, means 20A fuse is good, wiring good.
small red 0.6 v Normal, means Bank Angle Sensor in proper position providing ground for Engine Stop Relay operation.
bl/w 12.1 Normal, Output of Engine Stop Relay, provides power to Fuel Cut Relay
bl 11.7 Normal, proves Engine Stop Switch is on and wiring good and 10A fuse "D" is good.


fuel cut relay 4 wires,2 bl/w, 1 br, 1 br/w

br to fuel pump 0 Normal (based on ECU not connected) output of Fuel Cut Relay to power Fuel Pump
br/b 12v Normal, This is the control line from ECU, it turns the Fuel Cut Relay on/off. With ECU disconnected, no control possible.
2 bl 12v Normal, power coming from Engine Stop Relay


now w/ key off stop switch off

stop relay

fat r/w 12.7 v Normal, 20A Fuse good
small r/w 0 v Normal
b/w ground I'm assuming you mean 0v, (0v does not mean ground, which would be a short)
b 0 v Normal

fuel pump relay br ground (guess from fuel pump cause it is grounded) br/b ground, both black/ground.

now with ecu hooked up and key on and stop switch on

stop relay

fat red 12.6v Normal
small r/w 0.6v Normal, Bank Angle Sensor in proper position.
2 bl 12v. Normal, output for Fuel Cut Relay

fuel cut relay fat brown 0v shows ground(from fuel pump?) Should be 12v for a few seconds when Ignition Key Switch turned on.

br/b 11.2v Should be <1v for few seconds when Ignition Key Switch turned on
2-bl 12v. Normal, 12v supply from Engine Stop Relay


Questions I have

Have you checked the Brown/Black wire on Fuel Cut Relay at the moment you turn the Ignition Key Switch on to see if it goes from 12v to <1v to 12v ? (should happen for few seconds) ?

Are you currently getting any MIL indicators on your Gauge ?

Have you checked the Ohms (continuity) from the Green wire/pin 12 of ECM to frame ground ?

The ECM that you installed, did it come off a running bike ? How do you know ?

 

I re-tested the "now w/ key off stop switch off" to clear up the ground that I stated I had on the B/W. I must have had the ECM connected to get those readings (sorry it was early).

OK so here we have it...

ECM connected w/ key off & stop switch off

Stop Relay:
-Fat R/W = 12.7v
-Small R/W = 0v
-Bl/W = ground
-Bl = 0v

Fuel Cut Relay:
-Br = ground
-Br/Bl = ground
-Both Bl/W = ground

ECM NOT connected w/ key off & stop switch off

Stop Relay:
-Fat R/W = 12.7v
-Small R/W = 0v
-Bl/W = nothing; no ground and not 0v
-Bl = 0v

Fuel Cut Relay:
-Br = ground
-Br/Bl = nothing; no ground and not 0v
-Both Bl/W = nothing; no ground and not 0v


Now for your questions:
1. With the ECM plugged in and the key/stop switch to ON, the Brown/Black wire (coming from the ECM) jumps directly to 11._v. It DOES NOT hold a low voltage for any length of time, therefore the pump will/does not prime.

2. There are currently NO MIL indicators on the gauge. I cleared the old one (8 blinks = TP sensor) because I was only getting that code from unplugging the TP sensor to do a check. I re-checked for codes after clearing them and nothing. When I jumper the diagnostic harness the MIL stays lit. The service manual states that with the diagnostic harness jumpered, the MIL will light up if there are NO diagnostic codes. I've tried cranking the bike in hopes that the bike will throw some codes, but I still get nothing.

3. I checked for continuity on PIN-12 to a good chassis ground and I get steady continuity. I also checked for continuity on the other 2 PINS that the manual says to check and they also tested good.

4. I bought the ECM from a guy on this forum (Honda125 358). He said the ECM came from a good running bike. I personally did not see it running. This is the thread I bought it from, but he has, since then, edited it. https://cbrforum.com/forum/parting-o...f4i-pa-132668/


Do you have, or know anyone with, an 01-03 F4i? Maybe I could send you my ECM and you could test it out?

Thank you for all your help!
Ed

 

Update:

I went into the garage to see if the bike would start with the "new" ECM and with the fuel cut relay jumpered. The bike STARTS like this. I shut it off immediately incase i have some sort of short that friend the ECM last time. Like I said in the beginning of this thread...the bike used to start with the old ECM and the fuel cut relay jumpered, and then all of a sudden it wouldn't start anymore with the fuel cut relay jumpered. Does this give anyone any clues as to what might be causing this?

Something that I should also point out. WITHOUT the ECM plugged in, the pink wire from the ignition harness (zener diode) reads 10.1v. When the ECM IS plugged in, the pink wire reads 8.7v.

Does this seem normal?

Thanks!
Ed

 

The voltages you're getting while the Ignition Key Switch is in the off position are not really important.

Unfortunately I don't have access to a F4i otherwise I'd be glad to test it for you. Maybe someone here might step up, who knows.

Do you have 12v at the ECM on connector B6 ?

Everything here points to the ECM not functioning correctly. Make sure you've checked the other fuses. Unfortunately we don't know what the programming in the ECM says to do if another unrelated circuit is not operating properly.

Your Bank Angle Sensor is working fine because the Engine Stop Relay is providing 12v to the Fuel Cut-Off Relay. All voltages are present with the exception of the ground path that the ECM provides on the Black/Brown wire to the Fuel Cut Relay to energize it and turn the Fuel Pump on.

 

Yea I get 12v to PIN-B6. That proves that there is no open circuit between that pin and the engine stop relay.

I will recheck all my fuses next time I go back out there.

Yea...If only we knew the logic of the ECM. My problem would be solved weeks ago!

So you don't think there is anything odd with the zener diode reading 10.1v when the ECM is not plugged in?I ask because this is the anti theft feature of the bike and if the ECM thinks the bike is being stolen...maybe it cuts fuel and nothing else?!

 

Yes, it's possible that if the v coming in on that Pink wire is wrong, the bike won't start. I've searched through the documentation and I can't find what it's supposed to be. This certainly would be the symptom you'd get, no starting.

Check this thread/post. It may be your problem. https://cbrforum.com/forum/f4i-main-...e2/#post356316

 

Yea the manual doesn't say a thing about it because it's the anti-theft system. If they said things about it then it would be a general knowledge of how to steel the bike.

Thank you for the thread. I've checked that diode and mine is not blown like he says his is. I'm thinking about switching it out with a 2.2kOhm resistor anyways to see if anything changes.

Does anybody know:
If the voltage seen in the pink wire is 9v with the ECM plugged in, or 9v with the ECM unplugged? When my ECM is plugged in I get 8.7v and when it is unplugged I get 10.1v.

Is there anyone here that I could send my ECM to to test on your bike or possibly meet up with (zip 08731) and test it out?

Thanks!

 

after 2 or 3 fail attempts at starting up the bike. Does the FI light blink? does it have fresh gas?

 

Nope. No codes at all. I even jumpered the fuel cut relay and took the bike for a ride in hopes to get some code(s), but still nothing.

Yea it has fresh gas. When I replaced the pump I got rid of what was in there and put fresh stuff in.

That shouldn't have anything to do with it though because my pump won't prime. I know the fuel cut relay is good because i tested it. My problem is that the ECM is not grounding the fuel cut relay. For what reason, I do not know.