Spastic tach

[Cooter]

In the very beginning of your service manual:

http://buellmods.com/content/downloads/manuals/xbslightning/2004_lightning_manual.pdf

Page B-17



The pink wire that drives the tach comes directly from the ECM.
BECAUSE you said your bike runs fine while tach is spastic, all the signals TO the ECM are fine.
the signals TO the ECM are fine.
the signals TO the ECM are fine.
the signals TO the ECM are fine.

BECAUSE you said the speedo is NOT spastic at the same time, it eliminates any power or ground supply issue externally feeding the dash.
it eliminates a power or ground supply issue
it eliminates a power or ground supply issue
it eliminates a power or ground supply issue

SO

You have an issue internally in the power or ground or signal to the stepper motor that the tach needle is on inside the dash. Replace it*.

OR

You have a intermittent open in the pink wire circuit that goes between the ECM to the dash. Replace it.

Period.

Screaming into the abyss:indecisiveness:




* Buell XB mileage is held within the dash itself on a 'count-up' chip. So buy a dash with similar mileage.

 

[kz6fittycent]

I have no idea what you just said. I'm here to trouble-shoot my Kawasaki.

 

[mriulvr]

Cooter, thanks. That helps. I will try replacing pink wire first. If issue is stepper motor, may just live with it.

 

[Cooter]

Or instead of hacking into a OE wire harness unnecessarily, use a DVOM to check continuity while wiggling the wires and connectors. Can't afford a DVOM?
Heres a free one:


If you can't find an issue there, it's the dash. Can't afford one?
I'll send you the perfectly functioning guts of one to replace yours, for free. It's got about 32k on the Odo.

PM me if you want it.

 

[mriulvr]

PM sent
Appreciate the coupon and offer on dash guts. Have a DVOM and checked continuity of pink wire. Will double check with wiggle test. Weird part is that it is inconsistent. When it does start spazzing it is after riding about 15ish minutes and then starts happening above 3kish rpm then calms down below 3k. Doesn’t flash a CEL, produce a code, or cause any noticeable issues other than my becoming OCD about it.

 

[mmcn49]

Or instead of hacking into a OE wire harness unnecessarily, use a DVOM to check continuity while wiggling the wires and connectors.

If you can't find an issue there, it's the dash. Can't afford one?
I'll send you the perfectly functioning guts of one to replace yours, for free. It's got about 32k on the Odo.

PM me if you want it.

I have an ongoing similar issue. Checked the wires, grounds etc and have found nothing.

Where can you purchase a stepper motor?

 

[mriulvr]

Well, replaced the the dash guts with the one from Cooter. Took her for a ride and had the same issue although not as spastic as before. So, back to chasing a a wiring issue or a possible ECM issue. I did have a CEL after she had warmed up that only lasted about 20 seconds. Got back from the ride, connected ECM Droid, read error codes, and nothing showed up. This is driving me crazy.

 

[Cooter]

Got a way to get a video?

Will it do it in neutral?

 

[Barrett]

Well, replaced the the dash guts with the one from Cooter. Took her for a ride and had the same issue although not as spastic as before. So, back to chasing a a wiring issue or a possible ECM issue. I did have a CEL after she had warmed up that only lasted about 20 seconds. Got back from the ride, connected ECM Droid, read error codes, and nothing showed up. This is driving me crazy.

I did have a CEL after she had warmed up that only lasted about 20 seconds.

There's your confirmation. CEL in conjunction with NO stored historical. CEL momentarily saw voltage or resistance activity it didn't like. Failing ECM. Mentioned this years ago.

 

[mriulvr]

Got a way to get a video?

Will it do it in neutral?

Have not had any tach issues in neutral. Typically only happens
1. after riding for 10-15 minutes (possibly coinciding with engine getting to temp and ECM moving out of cold start enrichment?),
2. Above 3k rpm, and
3. Not consistently twitchy.

Not sure if it is just differences between my original dash and the Cooter dash (differences in model or year), but the Cooter dash tach is less sensitive to small RPM changes. For example, at idle it sits steady at 1k while my original would be at 1k with very slight movements. Almost like the original was showing a continuous RPM feed while the replacement is sampling or disregarding small fluctuations.

As for video, I might be able to set my phone up on my rammount so the camera captures the dash. Will have to check and might have to move it around to get it to work. If that works, I will get and share video as soon as I can.

Weird that no error code stored. Wish I had been data logging to see what showed up. However, as mentioned a few posts back, I keep losing connection between my Buelltooth dongle and ECMDroid soon after starting a ride. Can’t figure out if this is a separate issue or somehow related to tach issue.

 

[mriulvr]

I did have a CEL after she had warmed up that only lasted about 20 seconds.

There's your confirmation. CEL in conjunction with NO stored historical. CEL momentarily saw voltage or resistance activity it didn't like. Failing ECM. Mentioned this years ago.

Anyone have a functioning ECM for an 04 XB12S they would like to sell? Looked at IDS and they want $500 for a new one. Would trust someone on here more than eBay.

 

[mriulvr]

Located and purchased an ECM from a 2007 XB12 (which is suppose to be compatible with 2004), installed it on my 2004 XB12S, reset the TPS, flashed the maps that I saved from my ECM before uninstalling, and went through the EEPROM settings to make sure they were the same.

Before I do anything else, I have a question. The EEPROM from my original ECM is BUEGB and the EEPROM in the replaced ECM is BUEIB.

What I was wondering is if the flashing of my maps and the TPS reset is all I need to do or are there other settings or changes I need to make to the ”new” EEPROM? Any differences between these two EEPROMs that I should be aware of and change?

Have been out of town the last two weeks to be with family in Indiana after my dad passed and am now scrambling to get caught up at work. We had an ice storm here in DFW last week that shut everything down. So, have not had been able to get back to this for awhile but hoping to get her out on the road soon to see if this fixed the tach issue.

 

[mriulvr]

I downloaded the EEPROM directory for BUEGB and BUEIB from the ecmspy website, imported them into a spreadsheet and compared them. There are differences that I would assume would preclude the BUEIB EEPROM from working with my 04 XB12S. I have read the the ECMs for 2004-07 are the same but the EEPROMs are different. So,
1. is there a way to erase the BUEIB EEPROM and flash my BUEGB EEPROM, or
2. edit/reprogram the BUEIB EEPROM so the correct data has the correct offset and type, or
3. do I need to buy a new ECM and EEPROM update from IDS for $500?

I am familiar with ecmspy, have a wide-band O2 sensor installed, have tuned, etc. but actually changing the EEPROM itself, if possible, is new territory for me.

 

[mriulvr]

If anyone would like to have or find the BUEGB vs BUEIB spreadsheet helpful, IM me and I will share it.

 

[Cooter]

I don't know about ECMSpy. But I know that EEPROMS are not compatible. Thats where the 'you're gonna brick your ECM' came from. ECMDroid has a safety built in to disallow different EEPROMS from burning and bricking your ECM. Will ECMSpy do it? I dunno.

You can (maybe) get a flash from HD but that will make your ECM a BUE2D firmware version and include all the OE latest mapping (from 2010 lol), and it will now be compatible with every other BUE2D tune.

I have more ECM's, some I have never opened, so I have no idea firmware version they are. I'm travelling now, but if your latest guess is to replace the ECM, I'll see what I can do to get you one.

 

[mriulvr]

Thanks Cooter. As always, appreciate your help. If you don't have a compatible ECM, no worries. Just let me know and I will either get one through IDS or St Paul HD.

Thinking of giving her a new nickname, Scarecrow. If I only had a brain.

 

[mriulvr]

Update: Here is information that I had not been able to find elsewhere. Tim at IDS told me that the 2007 ECM with the BUEIB eeprom I bought will work on my 04 XB12S. He said that I f I sent them my ECM, they would actually upgrade the older/original BUEGB eeprom to BUEIB.

I had already installed the 07 ECM, used ECMspy to check settings, and did a TPS reset. Still need to update the maps to the Drummer/Hawk maps I got from Buelltooth. Will get that done this weekend, cold and rain this weekend anyway. Will get her out this week and see if the spastic tach issue is resolved. Curious to see if the newer eeprom makes any noticeable differences. Fingers crossed.

 

[mriulvr]

Barrett, gotta give credit where credit is due. Replacement ECM seems to have done the trick. Just got back from a 40 minute ride. No stutters, no CELs, and tach was solid. She’s alive!

 

[Barrett]

Barrett, gotta give credit where credit is due. Replacement ECM seems to have done the trick. Just got back from a 40 minute ride. No stutters, no CELs, and tach was solid. She’s alive!

My pleasure Sir and glad you resolved the BUE and EEPROM lingering questions. I have virtually no understanding or knowledge of anything related to those ECM aspects, but knew a long time ago as mentioned, that it was your ECM failing. Occasional ghost-type rideability issues...random CEL activity with no stored active or historical fault codes...erratic tachometer needle action...occasional irritating long-to-start cranking times....NO start when hot....all symptoms of a failing ECM.

 

[optomist]

Hello all, been away from here for a long time time. Traded the Uly for an XR1200 Sporty. It was OK but just OK--didn't really handle that great plus blew out my wrists. HD just bought it back (they were low on inventory) so was able to get out from under it. Now putting around on a Suzuki V-Strom 1200--which is a good all arounder.

Anyway--whats with the new www.buellmotorcycle.com ? Looks like an EBR Hodgepodge--taking orders for 2025?

Any gossip, news on this?

Sorry to hijack this thread but couldn't figure how to start a new one

Optomist