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I'm making this post in an attempt to get my bike running again. A few weeks ago, I took my bike to work and when I tried to start it up to go home, the fuel pump didn't prime and therefore the bike didn't start. The engine will still turn over, but will not start. I have read through many forums but can't seem to determine the problem with my bike. When turning the key, the engine stop relay under the cowling clicks, but the fuel cutoff relay under the seat doesn't click at all. I know it should turn on for about three seconds to pressurize the fuel system and then back off, but it doesn't turn on at all. I have checked all of the fuses in the fuse box and they look good as well as the 30A main and it looks just fine too. Went ahead and cleaned the contacts to be sure they weren't the cause. I removed the front cowling to test the bank angle sensor and it is working properly. When turned on it's side, the engine stop relay clicks of. I have also applied 12V to the fuel pump and it works. I have also checked all four of the relays that are compatible so I know it isn't due to a dead relay. For some reason, the fuel cutoff relay isn't being triggered and I believe this to be the root of my problem. Unfortunately, this leads me to believe that my ecu/ecm is dead since all of the leads for that relay go to the fuel pump or computer. I took some voltage measurements but can't recall exactly what they were. I remember one of them was around 12V and another around 300mV which seems off, almost like a bad ground or something going on. According to the FSM, I need a special testing harness to properly test the computer, but this harness doesn't exist online or on ebay. Does anyone know what the voltages at the relay plug should be since this will help zero in on the computer? I also have not tested the continuity between the relay and ecm which could be a problem. I'd rather not buy a used computer to find out it's not the problem. Thanks for any input! I love this bike but it really has got me pulling hair out right now!

TLDR; I suspect my ecm is faulty and is not activating the fuel cutoff relay, therefore not priming the fuel system.
 

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have you checked the 20Amp Fi fuse, also check the 12Pin Blue connector Harness side of the BAS in case burnt, can you back probe the Black/White wire at the ECM for battery voltage , also back probe the Green wire at ECM for continuity to Earth, are you USA or UK
 

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Heeza Y Zasch
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I have also checked all four of the relays that are compatible so I know it isn't due to a dead relay.
I appreciate how thorough your troubleshooting technique is, as well as your post :thumb: Have you "swapped" relays, or just "tested" them?

Also, have you investigated the two-wire connection at the clutch perch and/or the connection by your shifter for the neutral safety switch? I haven't the schematics memorized, so I don't remember where those components are in the circuit (before or after), but they're worth investigating before investing in another ECM.
 

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I'm making this post in an attempt to get my bike running again. A few weeks ago, I took my bike to work and when I tried to start it up to go home, the fuel pump didn't prime and therefore the bike didn't start. The engine will still turn over, but will not start. I have read through many forums but can't seem to determine the problem with my bike. When turning the key, the engine stop relay under the cowling clicks, but the fuel cutoff relay under the seat doesn't click at all. I know it should turn on for about three seconds to pressurize the fuel system and then back off, but it doesn't turn on at all. I have checked all of the fuses in the fuse box and they look good as well as the 30A main and it looks just fine too. Went ahead and cleaned the contacts to be sure they weren't the cause. I removed the front cowling to test the bank angle sensor and it is working properly. When turned on it's side, the engine stop relay clicks of. I have also applied 12V to the fuel pump and it works. I have also checked all four of the relays that are compatible so I know it isn't due to a dead relay. For some reason, the fuel cutoff relay isn't being triggered and I believe this to be the root of my problem. Unfortunately, this leads me to believe that my ecu/ecm is dead since all of the leads for that relay go to the fuel pump or computer. I took some voltage measurements but can't recall exactly what they were. I remember one of them was around 12V and another around 300mV which seems off, almost like a bad ground or something going on. According to the FSM, I need a special testing harness to properly test the computer, but this harness doesn't exist online or on ebay. Does anyone know what the voltages at the relay plug should be since this will help zero in on the computer? I also have not tested the continuity between the relay and ecm which could be a problem. I'd rather not buy a used computer to find out it's not the problem. Thanks for any input! I love this bike but it really has got me pulling hair out right now!

TLDR; I suspect my ecm is faulty and is not activating the fuel cutoff relay, therefore not priming the fuel system.
Anyone near you with a 954 to test their ECU?
 

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Discussion Starter #5
have you checked the 20Amp Fi fuse, also check the 12Pin Blue connector Harness side of the BAS in case burnt, can you back probe the Black/White wire at the ECM for battery voltage , also back probe the Green wire at ECM for continuity to Earth, are you USA or UK
I have heard that's inline between the battery and a relay, but I'm not sure what it looks like or where it really is. I will check the blue connector and voltages when I can this week. I am in the USA.


I appreciate how thorough your troubleshooting technique is, as well as your post :thumb: Have you "swapped" relays, or just "tested" them?

Also, have you investigated the two-wire connection at the clutch perch and/or the connection by your shifter for the neutral safety switch? I haven't the schematics memorized, so I don't remember where those components are in the circuit (before or after), but they're worth investigating before investing in another ECM.
Thanks! I physically swapped them all the the engine stop relay location and cycled the ignition to test each one. I took a look at the connectors that attach to the clutch perch but have not looked at the connection by the neutral safety switch. I'll take a look at that too.


Anyone near you with a 954 to test their ECU?
Unfortunately no one around has another 954. I'm in a small town at the moment.
 

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Hi 20amp FI is in the fuse box , but also while your there check the diode just in case ,although the 20amp Fi fuse shows as "F" on the diagram could be some ambiguity as to position "E" but as long as all 3 20amp fuses are ok there's no problem
Diode check , also a diagram to show positions of relays
 

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Also check the master ground my friend had the same problem literally had the bike for sale when at one last atempt located the master ground was loose everything except his fuel pump worked fine he even took it in to professionals and they couldn’t find anything wrong it was a nightmare anyway im no super tech just felt I needed to mention that because it reminded me of that situation.good luck and God bless .
 

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Hi 20amp FI is in the fuse box , but also while your there check the diode just in case ,although the 20amp Fi fuse shows as "F" on the diagram could be some ambiguity as to position "E" but as long as all 3 20amp fuses are ok there's no problem
Diode check , also a diagram to show positions of relays
Yep, I checked all of those fuses and they look just fine. Also no corrosion on the terminals. I forgot to check the diode but I'll do so tomorrow. Are you sure that diagram with the fuel pump is relevant to the 954rr? The wiring diagram in the sticky looks different and the wire colors do not match. For example, the engine stop relay in the sticky diagram has black/white, red/orange?, black, and red/white while the diagram posted has colors black/pink, black, red/green, and black/white.

Also check the master ground my friend had the same problem literally had the bike for sale when at one last atempt located the master ground was loose everything except his fuel pump worked fine he even took it in to professionals and they couldn’t find anything wrong it was a nightmare anyway im no super tech just felt I needed to mention that because it reminded me of that situation.good luck and God bless .
Yeah I checked the ground. Unbolted it, inspected the the contacts, and put it all back together.

Today I had some time to mess around with it and it still won't prime. I got the multimeter out first to begin testing for continuity referencing the wiring diagram posted in the sticky. The ground wires on this bike are mostly green. I had continuity from the fuel pump metal to the green pin on the fuel pump side of the plug, and then i had continuity from the green pin on the frame side of the fuel pump connection to the main ground and frame. This proves that the fuel pump is properly grounded. There was also continuity in the following connections:

Fuel cutoff relay plug black/white to ECM black/white (light gray plug)
Fuel cutoff relay plug brown/black to ECM brown/black (black plug)
Fuel cutoff relay plug brown to fuel pump plug brown
Fuel pump plug green to frame (as said above)

This is all in accordance with the wiring diagram as posted and shows there is not an issue in continuity. I'm not exactly sure how the fuel injection system on this bike works, but it seems that the green is the ground for most components to the frame. Then it seems that the black/white wires are a common ground to the ECM/ECU for relays, servos, valves and fuel injectors. I took some measurement from the fuel cutoff relay to determine if the ECM is at fault. Assuming the black/white wire is a ground, I measured 120-150mV between the brown/black wire and black/white wires. The relay plug has two pins with a black/white wire and the measurement was the same from either one. If I'm not mistaken, I was expecting 12V here since this circuit should be activating the relay to power the fuel pump for 2-3 seconds before starting. I cycled the ignition and kill switch. In the off position, i measured 0V and in the on position, 120-150mV. It did not decrease after 3 seconds so something is definitely up with the computer unless I'm measuring this wrong. I have a basic understanding of relays so maybe I'm getting this wrong. Please chime in if i should measure it differently. Looking at the diagram, the fuel pump plug has three wires, the brown wire which goes the the fuel cutoff relay, a green grounding wire, and a brown/black wire which I beleive is unrelated to the brown/black wire on the fuel cutoff relay as it goes to the instrument panel to display the low fuel light. I feel like I'm exhausting possible faults. There is good continuity in my wires, all fuses and relays look good, the fuel pump works when wired directly, the bank sensor works, etc. I want to take a voltage measurement between the brown and green pins at the fuel pump plug to see if it's getting any voltage, but forgot to. Unless I'm missing something, this seems like an issue with the ECM. Thoughts?
 

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Hi the wiring diagram I sent you was only for showing the position of the relays, and was from the Honda PGM-FI manual, wire colours could be different , but the Black/White wire is not a ground, have you had the spark plug out to see if they are producing a spark, reason I'm asking is to make sure of the ignition pulse generator, check the red 2 pin connector from the pulse generator is ok, also checkout sidestand switch and neutral switch page 19-18 of the manual , dont like to give up on the ECU not really an item that fails readily,and here is the Honda PGM-FI for you.Did you take the Relays off the bike to test them? :wink
 

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Ive got the exact same problem with my 2003 954. i stopped for gas one night and it took a couple of flicks of the kill switch to get the pump to prime. then about 20 min later i stopped to use my phone and that was the last time it ran. no start, no fuel pump on, no spark. ive REPLACED the relay for fuel cut off, a new oem ignition, mtested and cleaned every connection on the bike, kill switch looked fine, clutch contacts are fine, fuses are all new, sidestand and neutral switches are good. the little diode in the fuse box is the only thing ive NOT replaced although it tested ok. WHAT THE F*** ELSE COULD IT BE EXCEPT THE ECU? I LOVE THIS BIKE!!! I dont want to part it out or junk it , but i dont need a red and black 375lb paperweight in my garage!! i was literally in tears over the frustration of NOT being able to fix something as loved as y 954, but ive REALLY reached the end of my rope and patience with it... any suggestions would be appreciated. im really bummed over this crap and ive owned 3 900rr in the past and this is the only bike ive enjoyed more than those, but FUUUUUUUU** ME!! im about to meltdown over this issue. the ecu is just a little pricey for it not to be the problem. youd think honda would have a solution for this problem since all of these forums are packed with this EXACT same problem with this particular bike. thats all i have the energy to rant about for a minute....lol....then crying! like i said i really dont want to get rid of it in any way. and im open to any suggestions atp. thank you to whoever made it this far through this sob story.
 

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Well i got the damn thing fixed!!! I cant believe it...lol. literally the night before i was going to go buy a new bike with money my gf gave me cause i was so bummed about it. But it turned out to be the CAM PULSE GENERATOR. IM NOT SAYING ITLL FIX EVERYONES "NO START" , but it fixed mine when everything on the bike trsted out as ok. All wiring was good, i joined and soldered all grounds, all new relays, new fuel pump, new ecu (ended up w old one back in), new handlebar switches (r & l), all components of the starting circuit were good. New ign also...lol. but it was the CPG on the front left of the cylinder head looking from above towards the front of bike. About $130 amazon. Hope it solves some problems for any body.. good luck all, I'm going riding again! Lol
 

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just in case someone else wonders into this thread looking for possibilities to a non priming fuel pump.

few days ago went to ride and fuel pump wasnt priming.

was all set to start swapping relays to test when i pulled the main wiring loom from the right side of the bike under the air duct cover, two connectors, a gray and a light blue set.

i had a burned/melted wire within the blue connection point.

tabs were black, cleaned them up and put some dielectric grease in and viola.

i feel lucky. wiring issues can be tough to track down and here i stumbled onto the issue the very first place i look. just by looking with my eyes. :)

anyway, if your fp isnt priming, start at the easiest spots to inspect first! you might just get lucky.
 

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Just wanted to add for anyone else fighting with this -- Just went through the hassle of replacing my entire pump because I tested and saw 12v @ the harness and ground tested good; Applied 12v directly to the pump wires and no go.

Replaced the whole f'ing thing and same shit. Looks like out of the 3 wires in that harness, the 12v pump wire is no good -- still wont run w/ 12v & ground directly from the battery -> connector coming from bottom of tank.

...and of course, the old pump powers up in my hand w/ 12v directly to it's terminals. I probably should have checked that before I swapped it and put the whole thing back together ... or at least checked that the new one worked through the harness.

But then again, who expects a wire to randomly go bad?

For some background, did a bunch of maintenance the week before last, rode it twice that week, three times last week. Took it to a friends on Wednesday, hung out there for a bit, fired it up and rode home ... and come Thursday, turn key and fuel pump doesn't prime. I still can't explain this one ... but I guess I'm lucky it happened sitting in my garage vs. the alternatives...

edit: meant to, but didn't say - it's an 03 954rr, 16k-ish miles on it
 

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Believe it or not, it was the wierdest, most unexpected issue ever -- Tracked down a youtube video with one guy who had the same problem --

Unreal the pain in the ass this fix was, but tracking it down ... Once I installed a new pump and same crap ... that's when it became a bit more obvious where to look...

...but still, how -- that, I don't know. Both ends of the stock connection are ring terminals around a solid piece of either copper or bronze or some gold-colored alloy -- and were still connected. How this stopped passing current will be a mystery to me forever ... especially since it still conducts current on my desk.

Grrr, this one was bad.
 
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