'04 '05 ABS Motor Fuse

[ionbeam]

When the meter is on the diode scale and the red meter lead is connected to pin 6 and the black meter lead is on pin 1 and the meter displays 0.690 it means that both the diode and the ABS motor relay coil are good since they are in series and you read through both items.

Now that you know the two relay coils are good you need to test the contacts of the relay by powering the coils. The process is spelled out in the FSM, but I will paraphrase the Good Book with the following instructions. The solenoid relay (c ) and the ABS motor relay (b ) are independent and can be tested one at a time. It would be best to perform these tests using real Test Jumper leads with insulated alligator clips to prevent accidental shorting of +12 volts to ground. I've got a bag of Jumpers that I use, they look like these:

The way the ABS motor relay (b ) is drawn indicates that the contacts are normally open, then when 12 volts is applied to pin 6 and ground is applied to pin 1 the relay closes the contacts. With the coil energized there should be <10Ω between pins 2 and 5.

The solenoid relay (c ) has two sets of contacts. When the coil is not powered there should be <10Ω between pins 3 and 4. When you apply 12 volts to pin 7 and ground pin 8 the relay will turn on and switch the relay contacts so that you should now read <10Ω between pins 4 and 5.

 

[RadioHowie]

"Just ahead on your right, folks....it's the 'Exploding Head Zone'!"

Keep at it, boys.

 

[daviddowns2000]

Good work digging into this problem! I have a comment about the high resistance between terminal 6 and terminal 1 ----->

Terminal 6 goes to the anode of a diode. To measure continuity you would have to set your meter to the diode scale, then put the red meter lead on terminal 6 and the black lead on terminal 1. General purpose diodes will read between 0.400 and 0.750 on the diode scale. Your reading may be a bit higher due to the relay coil being in series with the diode. If you still have an infinite resistance reading like this, then the coil is indeed bad. If you don't have a diode scale on your meter there are other tricks available, let us know.

I am pretty dumb when it comes to electronics. With that disclaimer, why do you think the FSM directs us to use the analog meter on the 1 Ohm setting to test the coil? The instructions are the same for testing both relays. Is there something special about the Yamaha test meter that makes it unnecessary to use a diode scale? Is the 1 ohm setting the same as a diode setting?

 

[daviddowns2000]

Failsafe relay appears to be functioning correctly to the extent that both relays operate when voltage is applied to their coils and continuity is achieved across their switched contacts as specified in the manual.

SH!T, I thought it was solved until Ionbeam told me about needing to use the diode scale on my digital meter to test resistance across the coil of the ABS motor relay. I guess I should try to cancel the failsafe relay order I made yesterday with Ron Ayers.

 

[ionbeam]

...why do you think the FSM directs us to use the analog meter on the 1 Ohm setting to test the coil?...Is there something special about the Yamaha test meter that makes it unnecessary to use a diode scale? Is the 1 ohm setting the same as a diode setting?

The FSM specifies that when testing anything electrical you should use Yamaha P/N "YU-03112 -- Pocket tester --This instrument is needed for checking the electrical system". When using the Yamaha multimeter the 1Ω scale will read through the diode. P/N YU-03112 is a needle meter, not a digital meter.

Needle movement meters have many characteristics that are very different from digital multimeters. When you set a meter to the OHMS scale the meter puts out a voltage on the red meter lead and measures the amount of voltage or current that is returned to the black lead and then calculates resistance from the drop on the black meter lead. The diode scale on a meter puts out sufficient electrical drive on the red meter lead to forward bias the diode or transistor allowing you to read the true junction voltage. Evidently the Yamaha meter puts out enough voltage on the 1Ω scale to turn on the diode. If you are having a Mr Wizard moment you can hook up a meter set on the volt scale to the leads of a meter set to the ohms scale and measure the voltage being put out on the meter set to to ohms. Each ohms range can put out a different voltage, with the highest resistance scale typically putting out 6 volts or more.

There are occasions where ohming a circuit can actually damage parts. If you were to ohm sensors like the TPS or Atmospheric Pressure Sensor while it is plugged in you would be forcing voltage back into the ECU. The ECU may not like having voltage sent into the output pin. It is always good practice to unplug connectors before ohming sensors.

 

[Donal]

It might help to visualise a diode as a spring loaded check valve. When you apply 'forward bias' to a diode it's the same as applying enough pressure to open a check valve

Don

 

[daviddowns2000]

One thing that puzzles me is that when I test the coil of the motor relay component of the failsafe relay using an analog meter set to the 10 ohms scale I get a reading of about 2.5 but when I set the scale to 10K ohms I get a reading of about 25. Seems like a few orders of magnitude off. Forget it, I was all messed up, need to use my close-up glasses. Readings are as they should be.

Assuming that the failsafe relay is OK, what next? Should I just continue to muddle through the ABS pump and ECU electronic checks in the manual?

 

[daviddowns2000]

...why do you think the FSM directs us to use the analog meter on the 1 Ohm setting to test the coil?...Is there something special about the Yamaha test meter that makes it unnecessary to use a diode scale? Is the 1 ohm setting the same as a diode setting?

The FSM specifies that when testing anything electrical you should use Yamaha P/N "YU-03112 -- Pocket tester --This instrument is needed for checking the electrical system". When using the Yamaha multimeter the 1Ω scale will read through the diode. P/N YU-03112 is a needle meter, not a digital meter.

Needle movement meters have many characteristics that are very different from digital multimeters. When you set a meter to the OHMS scale the meter puts out a voltage on the red meter lead and measures the amount of voltage or current that is returned to the black lead and then calculates resistance from the drop on the black meter lead. The diode scale on a meter puts out sufficient electrical drive on the red meter lead to forward bias the diode or transistor allowing you to read the true junction voltage. Evidently the Yamaha meter puts out enough voltage on the 1Ω scale to turn on the diode. If you are having a Mr Wizard moment you can hook up a meter set on the volt scale to the leads of a meter set to the ohms scale and measure the voltage being put out on the meter set to to ohms. Each ohms range can put out a different voltage, with the highest resistance scale typically putting out 6 volts or more.

Head exploding. Still don't understand if the fact that my needle meter is showing 230-250 ohms across the motor relay coil means it is higher than spec range (50 - 150 ohms), or if the relay is really OK. The relay solenoids both operate when voltage is applied, but the motor relay seems to stutter occasionally when voltage is initially applied. Could just be contact bounce from touching the test lead to the battery terminal by hand, but the solenoid relay didn't seem to do it. As you can see, I really want it to be the failsafe relay so I can get some sleep.

 

[daviddowns2000]

As dd2000 mentioned earlier in the thread, I too have the non-functioning ABS system on my '04, and as SkooterG has admitted to, I haven't diagnosed mine either, but I had a thought as I was re-reading this thread...

Perhaps something that might be done to REALLY exercise the ABS pump would be to go through the complete procedure Ionbeam outlined with one MAJOR addition....

Attach a bleed hose to the rear caliper, crack the bleed screw, and THEN proceed with the ABS test. This would still exercise the system AND force new fluid through the pump. Might be a way to truly flush the pump of old, grungy fluid and correct a "frozen" pump issue.

Any thoughts anyone???

Well, out of desperation, I did what you suggested...and the bike exploded. Actually, it didn't help at all, rear still locks up.

 

[RadioHowie]

As dd2000 mentioned earlier in the thread, I too have the non-functioning ABS system on my '04, and as SkooterG has admitted to, I haven't diagnosed mine either, but I had a thought as I was re-reading this thread...

Perhaps something that might be done to REALLY exercise the ABS pump would be to go through the complete procedure Ionbeam outlined with one MAJOR addition....

Attach a bleed hose to the rear caliper, crack the bleed screw, and THEN proceed with the ABS test. This would still exercise the system AND force new fluid through the pump. Might be a way to truly flush the pump of old, grungy fluid and correct a "frozen" pump issue.

Any thoughts anyone???

Well, out of desperation, I did what you suggested...and the bike exploded. Actually, it didn't help at all, rear still locks up.

Worth a shot.

 

[daviddowns2000]

Update on my ABS problem:

The front ABS seems to be working. I had tested it a couple of times earlier and thought it was not working. Today, after replacing the failsafe relay, I road-tested both brakes again and the front brake ABS worked. I can't say for sure whether or not it was working all along earlier and I just didn't detect it or if something has changed. It did feel kinda clunky, however.

In any case, the rear ABS is definitely NOT working. Obviously, if the front works at all, this makes a big difference in what the likely suspects are.

 

[Fred W]

Update on my ABS problem:

The front ABS seems to be working. I had tested it a couple of times earlier and thought it was not working. Today, after replacing the failsafe relay, I road-tested both brakes again and the front brake ABS worked. I can't say for sure whether or not it was working all along earlier and I just didn't detect it or if something has changed. It did feel kinda clunky, however.

In any case, the rear ABS is definitely NOT working. Obviously, if the front works at all, this makes a big difference in what the likely suspects are.

David,

Was just digging into the FSM and think I may have a possible cause for your problem. On page 98 of the '05 ABS supplement is this note:

NOTE:

_

• If the rear brake hose inlet and outlet connections are reversed on the hydraulic unit, the brake

pedal is pressed down to full stroke without responding and will be pushed back slowly without

pulsating when the final check in [D-6] is performed.

This vaguely sounds like what you were describing in Test 2, doesn't it? Of course this doesn't explain why you are feeling no pulsation in the pedal at all when riding, but do feel something during the test.

It's actually starting to sound like an ABS ECU problem. If you were nearby I would volunteer to swap ABS ECUs with you to test it. Maybe there is another 1st gen ABS guy nearby that will be willing to help you out?

 

[Donal]

Now you're getting somewhere What you have just done is to prove that the system is capable of detecting a 'lock-up' and activating the ABS.

IIRC when you 'functioned' the ABS using the test plug you got a strong reaction on the front brake lever and a very weak reaction on the rear brake pedal. This would indicate that the pump is working properly and the front brake solenoids are working. What you need to do now is get your rear brake solenoids moving again.

I would try 'functioning' the ABS using the test plug multiple times and would be very empted to use Ionbeam's solenoid activation technique. I would also replace the brake fluid.

Good luck with the next stage :clapping:

Don

 

[daviddowns2000]

Now you're getting somewhere What you have just done is to prove that the system is capable of detecting a 'lock-up' and activating the ABS.

IIRC when you 'functioned' the ABS using the test plug you got a strong reaction on the front brake lever and a very weak reaction on the rear brake pedal. This would indicate that the pump is working properly and the front brake solenoids are working. What you need to do now is get your rear brake solenoids moving again.

I would try 'functioning' the ABS using the test plug multiple times and would be very empted to use Ionbeam's solenoid activation technique. I would also replace the brake fluid.

Good luck with the next stage :clapping:

Don

Thanks. I did replace the fluid a few days ago. Have done tests 1 and 2 more than a dozen times so far. Tried Ionbeam's Bulgarian anesthestic approach a few times, not really slamming the pump, but striking with a steel bar firmly several times...no go, but I plan to go back and whack it (the pump) some more, if only to let out frustration.

 

[RadioHowie]

I did replace the fluid a few days ago. Have done tests 1 and 2 more than a dozen times so far. Tried Ionbeam's Bulgarian anesthestic approach a few times, not really slamming the pump, but striking with a steel bar firmly several times...no go, but I plan to go back and whack it (the pump) some more, if only to let out frustration.

David,

Did you do a COMPLETE flush of the system, i.e., running about an entire pint through the system, front AND rear each?

I'm thinking just a simple "bleed" leaves a LOT of old fluid in the system.

 

[daviddowns2000]

I did replace the fluid a few days ago. Have done tests 1 and 2 more than a dozen times so far. Tried Ionbeam's Bulgarian anesthestic approach a few times, not really slamming the pump, but striking with a steel bar firmly several times...no go, but I plan to go back and whack it (the pump) some more, if only to let out frustration.

David,

Did you do a COMPLETE flush of the system, i.e., running about an entire pint through the system, front AND rear each?

I'm thinking just a simple "bleed" leaves a LOT of old fluid in the system.

I didn't do the fronts. I did run through about three reservoirs through the rear.

Actually more, now that I think about it because I bled the back twice. Do you think that new fluid vs one year old fluid would cause this failure?

 

[Fred W]

I did replace the fluid a few days ago. Have done tests 1 and 2 more than a dozen times so far. Tried Ionbeam's Bulgarian anesthestic approach a few times, not really slamming the pump, but striking with a steel bar firmly several times...no go, but I plan to go back and whack it (the pump) some more, if only to let out frustration.

David,

Did you do a COMPLETE flush of the system, i.e., running about an entire pint through the system, front AND rear each?

I'm thinking just a simple "bleed" leaves a LOT of old fluid in the system.

I didn't do the fronts. I did run through about three reservoirs through the rear.

Actually more, now that I think about it because I bled the back twice. Do you think that new fluid vs one year old fluid would cause this failure?

No. Old fluid may have caused the problem. The new fluid may be fine, but the damage may have already happened in the past on some old fluid.

I don't see the point of flushing with so much fluid either. Once you flush the clean fluid thru, cycle the ABS a few times and flush it through again, there is nothing further to be gained, IMO.

 

[RadioHowie]

I did replace the fluid a few days ago. Have done tests 1 and 2 more than a dozen times so far. Tried Ionbeam's Bulgarian anesthestic approach a few times, not really slamming the pump, but striking with a steel bar firmly several times...no go, but I plan to go back and whack it (the pump) some more, if only to let out frustration.

David,

Did you do a COMPLETE flush of the system, i.e., running about an entire pint through the system, front AND rear each?

I'm thinking just a simple "bleed" leaves a LOT of old fluid in the system.

I didn't do the fronts. I did run through about three reservoirs through the rear.

Actually more, now that I think about it because I bled the back twice. Do you think that new fluid vs one year old fluid would cause this failure?

Not sure...just hoping/wondering-if a speck/chunk of splooge holding a spool valve open/shut might get dislodged.

The (supposed) reality might be that moisture that's formed/collected in the system over its life may have corroded the rear-control spool valve into immobility. If that's the case, then the ABS moduled might be fuxored.

But we are ALL counting on YOU to figure it out, and come up with a way to take that damn thing apart and FIX IT!!!

 

[RadioHowie]

I don't see the point of flushing with so much fluid either. Once you flush the clean fluid thru, cycle the ABS a few times and flush it through again, there is nothing further to be gained, IMO.

Fred, I'm thinking/hoping that guaranteed new fluid, combined with MANY ABS cycles might flush/clean/lubricate a stuck or immobilized spool valve. Especially multiple, forced ABS cycles, using the ABS diagnostic sequence. What could it hurt? Break the ABS system? It's already not working. The only cost is in time.

 

[ionbeam]

Living in Mymammy there is certainly the opportunity for water to get into the hygroscopic fluid and cause gut rot in the solenoid spool valve. Another approach to the solenoid block may be to freeze the sucker. Here in New England the inside of the freezer is sometimes warmer than the outside air which contracts everything and may help keep the solenoids from sticking and staying stuck in an unheated garage

.