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Discussion Starter · #1 ·
I've a low mileage UK model GSXR-600 K7, used mainly for track events.

At my last event the bike failed. No power to anything mid-session, mid-bend. Parp.

Traced to blown main fuse and then to blown reg/rect. Reg/rect was badly scorched with melted connecting wires.

Replaced the reg/rect with an RMStator unit. Changed fuse. Got power back. Now have working instrument panel, lights etc.

Then saw the classic symptoms: no engine turnover when pushing starter; constantly clicking fuel relay; CHEC shown in display & no dealer mode available. Faulty ECM suspected.

Checked power & ground lines to ECM. All okay.

ECM unit not visibly damaged. Did notice some faint scorching on a couple of the pins.

My best guess is ECM was toasted inside when the reg/rect failed.

So I'm looking for a replacement ECM. Here's where the problem starts.

The OE unit new from Suzuki is an eye-watering £1,100. Adding to the pain, the UK model has an immobiliser feature. The service manual suggests my keys will only work with their factory paired ECM unit. I guess if I try replacing with another UK ECM, I'll also need to replace with paired keys and so also need to replace the ignition switch. A quick look at eBay shows UK ECMs are hard to find.

I was hoping instead to bypass this whole headache and replace with a used US ECM for about $400. I understand from these pages there's no immobiliser feature in the US ECM. So I can use my keys and ignition switch as they are now.

Before I jump in and maybe waste $400, does anybody know if swapping a US ECM into a UK model will work?

Thanks guys.
 

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Welcome.

Well the good news is that the R/R shorting and popping the main fuse is not uncommon and that I've never heard of it causing any more damage beyond the fuse.
It's funny that my track bike also did the same thing just past the apex at my local track. Beyond the bike dying and hoping no one is on your tail, the cloud of smoke was fun.

Here are some observations from the symptoms you describe.

The ECM is not needed for the starter to work so if it is not, there is something else going on.

The clicking fuel pump relay is a good sign as the fuel pump not working is a classic sign of a damaged ECM.

Showing "CHEC" is a bit puzzling as it means that the ECM is not sending data to the cluster. I'm wondering if the ECM is not booting up.

My guess would be to look for faulty power to the ECM. Some areas would be, faulty battery, bad battery cable connections, bad ignition switch, bad kill switch, loose or corroded pins in the connectors.

The unknown part to me is what the immobilizer does in this situation.

Regarding using a US ECM, the main harness is different because of the immobilizer. I just don't know how that would play with a US version. I wonder if you can get the ECM flashed to get rid of the immobilizer function?
 

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Discussion Starter · #3 ·
Thanks for the welcome & for your suggestions!

I checked the battery. It seemed good enough a couple of days ago. Today it is very unhappy. Will try again with a fresh one.
 

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Get the battery & charging system sorted out before doing anything more. That might be what CHEC and no dealer mode is about. However "faint scorching on a couple of the pins", if real, is not encouraging.

The wiring harness and ignition switch differences between immobilizer and non-immobilizers complicate swapping ECMs. A US ECM won't work unless you alter the leads associated with the immobilizer to incorporate the resistor in the US ignition switch. I think there are two leads, R/Y and O/Bl, plus Br/Y for indicator light for the immobilizer and a single O/Y lead for the resistor. I'm not sure but you might be able to leave the immobilizer leads in place and just add the resistor lead. However the antitheft feature has three settings, Immobilizer/Resistor/Disabled, so it's possible to just turn it off by a flash. This is OK for a race bike but not for a street bike. Check if there are legal or insurance requirements for a functioning immobilizer on a street bike before disabling.

This might suggest that you could just turn on the immobilizer in a US ECM. But the immobilizer key chip codes are stored in the same area where the fuel trim values are and you'd have to add them. I'm unaware of anyone ever doing that.
 

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Discussion Starter · #5 ·
Here's a snap of a scorched pin. The other connector has a similar scorch on one pin.

Automotive parking light Automotive tail & brake light Automotive lighting Hood Motor vehicle
 

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That looks like the grey connector. What are the wire colors of the scorched pins? Off hand it looks like the W/Bl ignition coil #1. Not good if that's what it is.
 

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Discussion Starter · #7 ·
That looks like the grey connector. What are the wire colors of the scorched pins? Off hand it looks like the W/Bl ignition coil #1. Not good if that's what it is.
Yes, it's the grey plug, pin 68. From the service manual pin-out, pin 68 is ignition coil #4.

The black plug had similar marks on pin 34, ground.

The old battery was totally shot. Maybe there was just enough juice to run lights & dashboard & fuel pump relay. And not enough juice to run ECM or starter.

(Or maybe both battery & ECM are dead...)

I should be back at it with a fresh battery next weekend.
 

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Discussion Starter · #9 ·
Ouch.

I took the ECM unit off the bike when I was checking it for damage. I wondered whether I could give it a simple bench test?

Something like: feed the ECM 12v power & see if the instrument panel serial data line (pin 6) sends any data signals.
 

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Ouch.

I took the ECM unit off the bike when I was checking it for damage. I wondered whether I could give it a simple bench test?

Something like: feed the ECM 12v power & see if the instrument panel serial data line (pin 6) sends any data signals.
I would not be comfortable doing that, 12v brushed to the wrong pin for a second and I don't think the ECM would be happy. As I recall, there are at least two power wires to the ECM plus you have to connect up the data wire and ground. I'm not sure what you are gaining by not just plugging it in.
 

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Discussion Starter · #11 ·
Tried a fresh battery today, Much improved although things are not right yet.

Now get: ECM showing "CHEC" then "---" when ignition & kill switch turned on. Can hear fuel pump priming.

Also get C00 code with dealer switch.

This is good news for me; looks like ECM is okay after all.

When starter switch is thumbed: starter motor does not turnover & cannot hear starter relay click.

Expect to be checking starter relay next.
 

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When starter switch is thumbed: starter motor does not turnover & cannot hear starter relay click.

Expect to be checking starter relay next.
The most common reason the starter does not work is the clutch safety switch. This switch provides the ground for the starter relay.

It is located just under the clutch lever pivot bolt and you should see the lever full release the plunger on the switch with the lever pulled back.

You can also follow the wires down to the connectors and temporarily jump the connection to eliminate the switch. You can't leave it this way as it is telling the ECM the clutch lever is back and it reduces performance.
 

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Discussion Starter · #13 ·
Good news. Bike starts and is running fine.

I didn't really change anything with the switches or their connectors; just wiggled the wires & this was enough to get it to start.

I'll do a more thorough check of these areas & find the dodgy connection.

The main thing is the bike starts & runs without needing to swap its ECM.

Thanks guys! Your good advice has saved me barking up the wrong tree & wasting a bunch of cash. Really appreciate it.
 

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That’s good news you’ve got her running.

The fun part is to trace the bad connections/possibly broken wires. Once you’ve sorted that out, she’ll be a rock solid bike.

Please post up pictures if you find any weird issues.
 
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