GV650 EFI Wiring issues

[whipflash191]

Bike Model = : 2010 GV650 EFI

Hi all,

I’ve been working on a GV650 I picked up as a non runner and have not been able to get it to spark yet.

I’ve already replacement the ignition circuit (new coils, caps, plugs, stator, pick-up, rectifier) with no dice so I’m leaning towards the ecu. Unfortunately however, its a daewoo and not replaceable and the pins have taken a hit. The D2 pin which is a black wire headed to the main relay has snapped and I’m leaning towards this being the issue with spark.

My question is this, what is the black wire *supposed* to do? My main relay doesn’t click at any point and a test light shows both red wires and the black wire being live with only the red/black wire not. I’ve tried grounding out the black wire at the relay and still nothing. No response grounding the other three pins either. The relay itself is functional. I swapped it with the side stand relay to test it there and it engages correctly.

Last question, does anyone have any tips on depining the ECU connector? Im trying to pull the wire so I can push out the remains of the busted pin but haven’t had any luck yet.

 

To answer some testing questions:

– No FI light, bike displayed generic Che error

– Fuses checked

– Pick-up, Stator & rectifier now within spec

– clutch switch bypassed by previous owner

– side stand switch works

– RO Sensor Checked upright as functional, need to check while bike is leaning.

[♠️ M77]

Hey, the link below:

Wiring Tables – GT650 / GT650R EFi ECU Pinout / Wiring Diagram & Speedometer

It may say GT650 , but considering you have a 2010 model as he does, the GV650 does share most of its similarities with the GT650, so use that link to look in to the wiring diagram Chris has made in the other post and let us know if it helped ?

Have you also stripped the harness down to find out where this mystery black wire goes ? Without pictures i am not able to verify what it does as Hyosung uses a lot of black wires in different places even as much as a horn! A solid black wire “could” be the fuel pump (as you said it is on a relay?) but again we can’t confirm until we trace it apart

There should be power going to the coils to spark? (Assuming the bike spins when pressing “start”) , also does the fuel pump prime nicely at all ?

I won’t lie , I have NOT dared myself to take apart a daewoo ECU plug as you said the harness or ECU can’t be ordered anymore , however, i was religious to use the “air duster” or compressed air” on the ECU itself (no liquids!) and also the harness plug

The harness = I used contact cleaner on every socket found on the bike, then compressed dry air on the smaller sensors such as injectors , lambda etc ,

The harness is the only thing that got soaked wet with contact cleaner but i let it dry overnight indoors to be absolutely sure (winters can get very damp outside here in UK, so best to do stuff in a dry area that’s warm) , you’re about to enter Spring season? So i will just assume outdoors are OK for you over there!

[whipflash191]

Hi Marcel,

Ive already traced the wire through the wiring diagram. It does directly from the D2 Pin on the ECU to the main relay and does not branch anywhere else. Ive confirmed its the main relay as all the relays match the wiring diagram from the service manual exactly however the relay never clicks. Ive tried grounding it and providing power to it and other pins on the relay but no dice. From my understanding I should expect this relay to click when the kill switch is off?

 

As to the bike turning over, it turns over happy and healthy just no spark. There is also power to the coils. The fuel pump does try to prime when the when the killswitch is flipped however like so many others from this year model, the outlet on my fuel pump housing has cracked off and I have yet to find a replacement that isn’t $300 from Korea. It was my understanding however that this should not affect spark.

[♠️ M77]

I fear that we may possibly have to clean the ECU connectors hard , then dry it off , but the ECU only having a dry clean (air blast only) and try to see if we can use the service manual to trigger a blinking red FI light. It’s that Fi blinking confirms the communication to the ECU and it will tell us the code by either telling us the number on the dash or doing a series of sequence blinks (most likely)

Can you also try to trick the ECU to throw an error code to see why it is not sending sparks ?

Or although the stator shows good readings but could we have an internal fault with the pulse sensor of the stator unit , in such that it can’t tell the ECU’s how fast the drum is spinning, thefore the ECU can’t send the pulses to the Sparking Coils to light up the spark plugs

The ECU should be alive , as only the ECU triggers the pump to prime => which should mean its ready to go? but you have power to the coils which is strange , i would also see if changing the HT caps & HT wires makes any difference incase of an internal fault with the HT wire or HT cap itself.

The last thing to do is a long process of stripping the harness and using a meter to very every “end to end” connection is verified and there is no lost readings in any of the wires you probe to test (incase of a short somewhere along the harness or a broken internal wire that is not visible but the meter would say zero (ie. Fuel Gauge Connector to Dash board – the yellow wire is dead , so explains why the fuel gauge is not telling what fuel level is in the tank etc or the pins have oxidized too much, so need some rescue)

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