Suzuki GSXR Forum banner

Engine suddenly dies

4K views 29 replies 7 participants last post by  Jimmy boy 
#1 ·
Hey guys, I’m having a weird issue with my 03 K3. Bike has lots of miles (152k) started acting up a few months ago. Cruising around 80 mph and suddenly dies .full bog. Lights and instruments fully lit. Engine dies and I hit the right on/off switch and clutch it since I’m still rolling and it fires right up . I thought maybe kick stand switch , so disconnected it. Then I thought maybe fuel relay, so replaced it. Now I’m thinking may right hand on / off switch? I don’t know why else something would shut the fuel pump off. I thought maybe pump, but when I restart it , it runs perfectly. Pump is a brand new oe with maybe 10k on it. What else would stop the fuel pump from running??
Thanks in advance
Jim
 
#3 ·
Good question. I’m going 80 on freeway and all I’m trying to do is restart the bike w/ out gettin killed. I will say if you hit starter or try to jump it when it dies , it won’t unless you flip the on/off switch on right handlebar. I’m going to have to try to look at the dash.
What if there is or isn’t? What could it point to?
Thanks
 
#8 · (Edited)
Is this a 600, 750, or 1000?

John may know better but as I understand it, the TOS only produces a FI error (C23) if the sensor is producing an out-of-spec voltage. If it's in a tip-over state but otherwise functioning normally, the engine will turn off without an error. So make sure that the TOS hasn't come off its mount.

It's fairly easy to rig up an indicator light to tell if the ECM is losing power. You can run leads from the O/W and B/W leads on the dealer mode connector forward to a 12 V LED located somewhere around the cluster. This doesn't have to be pretty, just use some duct tape to hold things in place. If the light goes out, the ECM is somehow losing power. That normally would be related to the interlock relay or kickstand switch. If the light stays on but the engine dies, that's normally due to the fuel pump losing power; either it's bad or isn't getting power (bad electrical connection or ECM is turning it off). You could move the LED over to the fuel pump relay (Y/R lead) to check that out. But you'll have to find somewhere for a ground connection, which could be the dealer mode connector.
 
#10 ·
Your comment about the starter cranking the bike but will not run till you recycle the kill switch sure sounds like a possible TOS issue as billyv mentioned.

But I also thought that there should be an FI fault code if the ECM is not happy with the TOS condition.
 
  • Like
Reactions: Jimmy boy
#11 · (Edited)
^My service manual says that the C23 error is produced if the sensor voltage is less than .2 or greater than 4.8 V. It goes on to say that the voltage is .4-1.4 V normally and 3.7-4.4 V when leaning more than 65°. I was curious and measured mine. It was .98 V until roughly 45° when it suddenly jumped to 4.4 V. That's what led me to believe that a tip-over will turn the engine off without the error. There's some circuitry, probably Hall effect, inside the sensor that's responsible for the bi-stable behavior.

The sensor is located beneath the tank and just ahead of the battery bulkhead. See 4-12 or 9-6 in the service manual.
 
#12 ·
I'll disagree. On his bike (a K3 600, 750 or 1k they are all the same) the TOS voltage only goes to the ECM which interprets it. If the ECM sees a value it does not like, it shuts off the fuel pump relay causing the bike to stop and since it sees this fault, it ports the C23 fault code to the cluster. The TOS does not shut the bike off directly.
 
#13 ·
^I'm not saying that the TOS shuts things down by itself. All it's doing is sending a signal to the ECM. If the voltage is outside of .2 to 4.8 V, the ECM will send the C23 error to the cluster. Don't know if it will also shut the engine off under those conditions, i.e. a faulty sensor. But a properly functioning sensor can send a signal to the ECM that will trigger an engine shutdown but, as best I can tell, not be an error condition.
 
#14 ·
^I'm not saying that the TOS shuts things down by itself. All it's doing is sending a signal to the ECM. If the voltage is outside of .2 to 4.8 V, the ECM will send the C23 error to the cluster.
True. And the computer (ECM) monitors the voltage and if it's out of range than it does two things 1. shut off the fuel pump relay 2. send the fault code to the cluster. It does not do one without the other.
The C23 is not a faulty sensor check, just monitors that the values are in range. It could be bad, unplugged or..... tipped over.

Don't know if it will also shut the engine off under those conditions, i.e. a faulty sensor. But a properly functioning sensor can send a signal to the ECM that will trigger an engine shutdown but, as best I can tell, not be an error condition.
Easy check. Start your bike, lay it over, the engine will stop in a few seconds, the red FI light will go on and "FI" will flash in the temp window indicating the C23 fault.
 
#16 · (Edited)
"C23 is not a faulty sensor check"

C23 is a malfunction code. A tip-over is not a malfunction. The 4.4 V tip-over voltage is in range. There's no mention of it here (K9 1000):


If C23 actually does come on in a tip-over, then the service manuals are in error. I've thought about trying it but tipping it over 45-65° is not to be trifled with. The red LED will come on because there's no oil pressure. I think a better way to test is to put it in dealer mode, start the bike, and tilt the sensor by hand. Either the manual is wrong or it should turn off without showing C23.
 
#19 ·
Rode it about 150 miles. First 75 it was flawless. 2nd day 75 started cutting in and out just a couple times. Totally different from before where it would fully shut the motor off. I’m starting to think ecu . It’ll probably start to get progressively worse and show it’s ugly head.

Does any know if a ecu can be tested off the bike?
 
#21 ·
Without reading everything from a month ago. Did you check the kill switch itself?

The reason I ask is that I would not think a failing ECM would immediately come to life again after cycling the kill switch. But an intermittent kill switch will do just what you describe.
 
#23 ·
If "CHEC" came on when the bike stalled, then I think we came eliminate the fuel pump as being the problem. Have you thought about doing what @billv said further up the page? Hooking up a 12v led/voltmeter to the dealer mode plug and running it to the front so you can monitor 12v feed to the ecu when it dies?
 
#25 ·
I recently bought this for use on a manual fan controller and am impressed. It's small but brighter than hell, runs off of 12V so current limiting resistors aren't needed, only draws 12 mA, and is cheap. Shipping will cost more than the part. The only thing that someone who's electrically challenged would have to watch is the polarity, the longer lead is positive.
 
#26 ·
Latest update. As I said in my last post it started cutting out left and right. Yes every time I cycled the on/off switch on right switch gear it would fire up. Never had any codes.
I put a used ECU on and so far nothing and bike runs very well.
This has taught me that if you’re going to have a older bike or higher mileage bike, that it makes sense to have a spare ECU as it is a complicated to diagnose all the different things that happens. Also spending money on the little things add up a lot. In the end extremely time consuming and I needed a ECU anyhow.
The only problem with used ECU is that I don’t know how many miles are on it , and only know that it’s just as old as the one I pulled out. New ones are 1,200 dollars. I’m not against buying a new one since my bike at 152,000 miles doesn’t owe me anything ?

Also want to thank all who helped me get through this .
Thanks
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top