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Discussion Starter #1
Need some help... Searched and read every thread and can't sort this out still...

2003 Rc51 12k miles. Bike has Power Commander and Satos. Aftermarket radiators with no cooling fan.

I bought it, only put about 1k miles on it when the FI Light came on.

Bike seems to run perfect which is confusing.

Light intermittently flashes and other times blinks. But always on in some way.

Tried jumpering the service connector and following the process as described in manual, but it just continually blinks in no pattern.

Looked for broken wires and inspected, cleaned and greased accessible connectors. Nothing abnormal noted.

Any ideas??
 

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With the bike running, in neutral, sidestand down, the dash will flash any active codes at you.


It could be a ground fault in the big grey connector. The FI lamp is illuminated when the wire between the dash and ecu is grounded.
 

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Discussion Starter #3
First, thanks for the reply!

Ok so check the big grey connector on the left side of the bike for obvious issues?

Any advice on how to check for a problem between the dash/Ecu wire (not sure which one you're referring to)?

Currently I have all the fairings, fuel tank and airbox off the bike to check wiring.

Thanks again.
 

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well what i'd do is unpin the FI lamp wire out of the ECU connector, then put my multimeter in its place and check for continuity to ground with the bike running. this would let me know if the ECU is actually calling for an FI lamp or if it's a circuit problem that's causing the lamp.


if it's a circuit problem i'd start digging, if it wasn't then i'd look into codes.
 

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Discussion Starter #5
Thanks again for helping me out.

Went through every connector and inspected again and greased. Found/Fixed a coolant leak at the thermostat. Found a poor seal on the Dan Kyle pair block off plate, (prior owner poor install) cleaned that up and resealed.

Found A kinked vacuum line at the throttle body, repaired that.

Cleared codes and the MIL seems to be acting properly. I have a code "10".

Went through diagnosis had to make a makeshift test harness and I've got 5.1v DC at the ECU. Range per manual is 2.7-3.1. seems to be a bad map (BARO) sensor. Application of vacuum nor pressure changed the current at the ECU.

Ordering one tomorrow and I'll update the thread incase other people are searching for answers in the future.
 

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code 10 is a very common one.

the baro sensor wiring lives in a separate connector that runs in parallel with the large grey connector to the front harness.

having a full 5v back from that sensor sounds more like a harness short than a sensor issue. if you unplugged the sensor did the input drop to 0v?
 

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Discussion Starter #7
Just unplugged sensor and tested.... Still 5V. Guessing it's a wire problem after all?
 

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where are you measuring 5v?

the yellow/red is the 5v positive feed
the green/orange is the analog common (basically just 0v)
the light green/black is the signal wire back to the ecu. it lands on pin 8 in the grey connector.

if you probe light green/black to green/orange, you shouldn't get 5v. if you do, you may have a short between the yellow/red and the light green/black. if unplugging the baro sensor doesn't clear this up, try unpinning the yellow/red from the ecu grey connector pin 1 and check again. if it's gone you can check continuity between the yellow/red and light green/black with the ecu connector unplugged, then start unplugging connections in the harness till you get an open circuit.

that's all i can offer right now man.
 

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Discussion Starter #9 (Edited)
Made an edit: added a picture with blue line that's more clear (I hope)

Maybe I'm measuring wrong, sorry for the back and forth.

Measuring yellow/red (bottom right grey plug at ECU)

And

The open hole (8th from top left) of black connector.

Tried attaching a picture with highlight.
 

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no... that's not right at all.

the yellow red is +5 volts. this is precisely regulated voltage source to all the sensors in the bike. if this was dead you'd have codes galore.

you should be measuring the signal input from the baro sensor.

you need to measure the voltage between the light green/black and the green/orange as i said before. i have no idea why you're measuring to an empty slot on the ECU



baro by William Glancy, on Flickr
 

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Discussion Starter #11
Ok my apologies. I thought the diagram on 5-26 of the manual was was showing the pin locations I needed to check.

light green/black and the green/orange has 5v. I (mistakenly) thought it was supposed to be as the manual said 4.75 to 5.25 was normal.

I'll have to do some searching to learn how to unpin the wire from the connector and finish what you said to do.

I did unplug the ECU and check for continuity from yellow/red to light green/black and there was no continuity.

Thanks again, none of the stealerships in town will even work on the bike because it's "too old". Your help is appreciated.
 

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sorry man i fucked up my diagram.

you want to measure between the light green/black and green/orange. per the manual A22 to B8

baro2 by William Glancy, on Flickr



this should be 2.7-3.1v (That's a normal input range for the sensor). when you are testing be sure your key is on and kill switch is set to run.


if this is 5v with the sensor connected, what i'd try is to pull the MAP sensor off the throttle body and swap it for the baro and check again. they are identical.
 

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Discussion Starter #13
I couldn't figure out how to unpin the wires... didn't want to take the tank off again...

Bought a new sensor and codes are gone! I think I was having multiple issues before, but once I massaged everything this was the only thing outstanding.

Thanks for all the help. Everything you provided was awesome. Hopefully all your posts will also help other people in the future.

I have a power Commander question, but I should likely start a new thread for that I guess.
 

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It's likely possible you just had a bad , possibly slightly corroded connection through a plug and you got rid of it temporarily by unplugging and plugging them back in. Get yourself a tube of dielectric grease and give every plug you can get at a dab in the holes of the female side.
 
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