ECM problem?
Thread Starter
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6th Gear
Joined: Sep 2016
Posts: 13
Likes: 4
From: Homestead, Florida
ECM problem?
Looking for advice on a starting problem on my 2008 Street Glide? I have good spark, no pinched/corroded wires, good clean fuel, and 60lbs fuel line pressure that holds for several hours so nothing with fuel appears to be the issue. My bike is a 2008 SG, 107ci, SE hi flow air cleaner, ported-flowed heads, 10.5 Carrillo pistons, Rinehart true duals, 259 cams and a ThunderMax ECM. One day the bike was starting just fine and a few days later it wouldn't start even though it's cranking over real good. So for ***** and giggles after checking the things I mentioned (spark-fuel-electrical wires) I took the air cleaner cover off and spayed starting fluid into the air filter so it would migrate into the cylinders and boom the bike starts.
After that initial start, "sometimes" not always, I can restart it a few minutes later without introducing any fuel manually (starting fluid through the air cleaner). I've changed the MAP on the Tmax thinking maybe that was the issue but that didn't fix it so I installed my original HD ECM and the bike starts up just fine without any starting fluid (of course I only used the HD ECM to do a start test and only to idle the bike for a few seconds) but what's important with that OEM ECM is that it starts up every time without me introducing fuel into the throttle body. So, the bottom line is in my thinking that there must be problem with my Tmax ECM not communicating with the injectors to spray fuel for a start up? Anyone got any other suggestions?
After that initial start, "sometimes" not always, I can restart it a few minutes later without introducing any fuel manually (starting fluid through the air cleaner). I've changed the MAP on the Tmax thinking maybe that was the issue but that didn't fix it so I installed my original HD ECM and the bike starts up just fine without any starting fluid (of course I only used the HD ECM to do a start test and only to idle the bike for a few seconds) but what's important with that OEM ECM is that it starts up every time without me introducing fuel into the throttle body. So, the bottom line is in my thinking that there must be problem with my Tmax ECM not communicating with the injectors to spray fuel for a start up? Anyone got any other suggestions?
Last edited by too many scooters; Mar 6, 2025 at 11:27 AM.
Stellar HDF Member
Joined: Jan 2017
Posts: 2,650
Likes: 2,052
From: Massachusetts
Did you try this?
This step is required for new module installation, or
when interruption of 12v power to the ECM takes place.
Example: battery change, removal of battery, ECM or
maxi fuse, etc. Turn the ignition switch on with the
handlebar rocker switch to the run position for 20
seconds, uninterrupted. After 20 seconds, cycle the
ignition switch off, repeat 3 times. Then turn ignition on
and start the engine. Let the motorcycle idle on its own
for 15 seconds. Cycle the ignition off and restart the
motorcycle
This step is required for new module installation, or
when interruption of 12v power to the ECM takes place.
Example: battery change, removal of battery, ECM or
maxi fuse, etc. Turn the ignition switch on with the
handlebar rocker switch to the run position for 20
seconds, uninterrupted. After 20 seconds, cycle the
ignition switch off, repeat 3 times. Then turn ignition on
and start the engine. Let the motorcycle idle on its own
for 15 seconds. Cycle the ignition off and restart the
motorcycle
Last edited by jake24lt; Mar 6, 2025 at 12:39 PM.
Stellar HDF Member
Joined: Jan 2017
Posts: 2,650
Likes: 2,052
From: Massachusetts
Not sure if you can setup the tmax module and record the cranking issue and send that to tmax.Ive done with a running engine, but not on a no start.
Thread Starter
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6th Gear
Joined: Sep 2016
Posts: 13
Likes: 4
From: Homestead, Florida
I'm 99.9% sure the problem is within the Tmax. I'm just waiting on a reply from Tennessee if they can locate the problem if I send them the module.
I've had the Tmax close to 7 years now and I know how to download MAP's and reinitiate the module to the bike. If the problem was some other mechanical or electrical problem it would act the same way with both ECM's not just the Tmax. The OEM ECM starts the bike every time after 3 cranks just like it should.
I've had the Tmax close to 7 years now and I know how to download MAP's and reinitiate the module to the bike. If the problem was some other mechanical or electrical problem it would act the same way with both ECM's not just the Tmax. The OEM ECM starts the bike every time after 3 cranks just like it should.
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Thread Starter
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6th Gear
Joined: Sep 2016
Posts: 13
Likes: 4
From: Homestead, Florida
Yes I tried that too with a new crank sensor and there was no change, the bike starts fine with the 2008 OEM race tuned ECM without any assistance. The bike doesn't start normal with the Tmax unless I introduce starting fluid into the throttle body via the air filter which tells me it has to be a Tmax issue since the OEM ECM starts the bike just fine. The ECM was sent back yesterday to Tmax support to figure out the problem. I'll update this thread once I find out what they have to say about or what repair they do to the ECM.