Electrical or ECM issue?

[foreignrider]

Hi guys. About a week ago I was riding and the check engine light came on, rode for a little bit and then the light went out but when i came to a stop the bike shut off completely and started clicking (as if battery was dead) when I tried to start it up. I did all the necessary tests... Alternator and stator passed. Got the battery tested at Battery+ and it failed the load test got a new battery (Duracell DURAGM-14-US) While hooking it up I shorted it though the ratchet into the body. I ended up hooking up the battery and calling it a night the next day the roommate tried to start the bike, it turned over and the fan turned on and stayed on so he shut off the bike and didn't think too much of it. I charged the battery fully and hooked it up, the fan started running right away and the gauges (speedo and tac) maxed out and came down, turned the key to the on position, the gauges all did their thing and then the check engine light started giving different trouble codes (11, 15, and 44. TPS short to ground, Intake Air Sensor short to ground, BAS short to ground).. tried getting them cleared with ECMspy, still there. Tried waiting for the fan to stop, instead the bike started turning the fan, check engine light and priming pump on and off) so I unplugged the battery. So far I've checked the fuses, diode and the relays in the faring, all ok. Checked the fuse under the seat it's fine too. I have no idea where else to look or where to start or what the problem might be. Fried ECM? (That's codes in the 52-55 don't have those) Do TPS, BAS, and Intake Air Sensor share anything (wires, fuses, etc... one place where all three connect where it all went bad) Any help would be appreciated.

 

[user_deleted]

a year or so ago 2 board members posted up virtually identical scenarios. one inadvertently shorted positive post to ground during battery install....the other inadvertently connected the battery cables to incorrect terminals during install. in both instances they bricked the stock ecm units. before you anti up for new consider seeking out another buell owner either on here or in your area who might lend you his matched ecm for trial. as you indicated with codes, all the sensors and tps going to ground sounds ecm related.

 

[foreignrider]

I checked the wiring diagram to see if I could make sense of all and the three (TPS, BAS and IAT) do share a wire (BK/W) which goes into the "sensor ground" in the ECM, but that doesn't explain why the fan runs constantly (changes RPM hi to low). The four only share the ECM. There are other components on that wire, (VSS, CMP) but the ECM doesn't have codes for those. IF the ECM is fried, makes sense why the fan would go off when the battery plugged I would guess and why it shuts the bike down and turns it on. I'll check on the FB page if there is anyone who lives in my area and would trust me with their ECM.

 

[WIGGLE2]

What are you riding?

 

[foreignrider]

I ride an XB12R 2006. Some mods; D&D exhaust, K&N Filter, remap of the stock ECM, HID headlights, breather reroute and a right side scoop.

 

[WIGGLE2]

Ahhh...shoot. I have an ECM for an '03 '9'. I bought it, but can't use it....I'd have left you try it. Sorry!!

 

[foreignrider]

Thanks Wiggle.
I decided to check the "BK/W" wire that the three share to make sure it hasn't rubbed through and it grounds to the bike somewhere, also I'll check the BAS, TPS and the intake air sensor to make sure they aren't fried. Still not sure why the fan starts up when I plug the battery in but my guess is either the wire is shorted, engine temp sensor busted ot the ECM fried. (I honestly think it's the ECM but I want to make sure before I spurge on a new one)

PS I forgot to mention on Sunday when I got the battery and after I charged it for a while I threw it in the bike and it started normally, so I shut it off to get my gear on. When I came out to the garage turned the key the fan kicked on right away and it went back to giving me the trouble codes... Could there be an intermittent short? Possibly. IDK I'm really confused. [confused]

PSS
Couple questions.
1) In the schematic I'm looking at (pg 4-97 of the manual, 366 in the manual PDF) it shows there are 3 grounds. Are all three by the battery on the negative wire or are the other 2 hidden somewhere else?
2) The race ECM vs stock. If correctly remapping a stock. Any difference between the two? Does the race add anything?

Thanks guys. I appreciate all the help!

 

[foreignrider]

Also I noticed my tac and speedo do the max-min thing when I plug the battery in with the bike being in the off position...

 

[WIGGLE2]

As for the re-mapped stock ECM vs. the EBR or 'RACE ONLY' ECM.....*IF* it was done properly, a re-mapped stock ECM should be comparable or better, depending on HOW it was mapped. The EBR and RACE ECM are nice 'generic' plug and play ECM's that work quite well for a lot of combinations out there.

 

[foreignrider]

Update: checked the wire the three share. It has continuity and it doesn't ground to the body. The IAT Sensor has the correct resistance for the ambient temperature. I'm trying to figure out how to test the BAS w/I a breakout box. I'll plug ECMSpy to check the voltage of TPS. I did a resistance test on the BAS and it responded like it was sticking but I don't have a clue how it actually works except for the basic (I did see in the manual that the bike is rideable with a failed sensor though pg. 4-84).

 

[ReadyXB]

Couple questions.
1) In the schematic I'm looking at (pg 4-97 of the manual, 366 in the manual PDF) it shows there are 3 grounds. Are all three by the battery on the negative wire or are the other 2 hidden somewhere else?

I have a 2006 Ulysses wiring harness for comparison. The two ground wires from the ECM (Black Connector[2,11]) each have their own ground terminals but they ground at the same place in the tail. Not sure if the 2006 Firebolt merges those two ECM grounds into one ring terminal, but regardless, they should ground at the same point in the tail area.

Have you tried clearing the codes, and then unplugging the TPS, IAT, and BAS sensors from the harness to see if the code(s) change or go away? If the codes stay, it sounds like the ECM may be shorted internally.

 

[foreignrider]

Hey ReadyXB. I just unplugged the TPS, IAS and BAS... one by one, clearing the codes every time. Nothing changed. I believe that all ground in the same point at the tail.

 

[foreignrider]

Also I hooked up the ECMSpy to see the voltage at the TPS and it was not responding. I assume that ECMSpy gets all that information from the ECM and if the ECM is shot then it doesn't see the positions, voltage, etc. from the TPS.

 

[ReadyXB]

Yes - ECMSpy requests live data from the ECM, and the ECM reports back with all sorts of engine and sensor parameters.

Here's another simple test: unplug both ECM cables. Set your multimeter to 200K ohm scale. On the gray ECM connector, check the resistance between ECM (not the cable) pins 2 (TPS input) and 7 (sensor ground). You should get around 180K ohms. Be sure to check the correct pins! It's easy to get lost with the cables removed, lol.

 

[foreignrider]

2-7 on the ECM side with the ohmmeter set on the 200k scale it was reading 115.9 to 116.3 the positive of the ohmmeter was set on 2 and the negative on 7, also tried it vice versa because I was curious and it read 65. What do those numbers mean?

 

[ReadyXB]

If you had much less resistance to ground on Gray connector pin 2, the results would be more definitive.

Super easy: Unplug both BAS and IAT sensors. With the ECM connected, turn on ignition and run/stop. You should have 5 volts at the BAS harness connector Lt. Green/Gray wire pin. Note: this is NOT the Red/White connector pin, which also has 5V. Also, you should have 5V at the IAT sensor harness connector Lt. Green/Yell. wire.
On both of these wires with no load, the ECM apparently has them internally pulled up to 5V. That is what we are checking for, since the ECM says they are shorted to ground. When checking these pins, use the same ground as the ECM for your multimeter negative lead.

 

[foreignrider]

Just checked it. I'm not too familiar on how to use the multimeter, but when I set it on the 20 scale on the DCV (10 MegOhminput) side both plugs read 0.03. But when I put it on the side where I check the car battery if it's dead or not it doesn't register on the 1.5V scale. (I assume the bike runs on DC except for the voltage reg) [confused]

 

[foreignrider]

This is what I got for a multimeter.
http://www.equus.com/Product/3310

So The yellow side (20) it read 0.03 and green side (1.5) it read 0.00 and that's the same for both with the key in the on and off position.

 

[ReadyXB]

I'm glad you posted the link to your multimeter. You don't want to use the Battery (green) side for our purposes! Only DCV (yellow) is needed for that last test. But your results showed 0.3V on the 20V scale.

It would seem that they are shorted to ground inside the ECM. I checked a DDFI-2 ECM and it measured 5V on the specified connector pins with no sensors attached. Additionally, the ECM reported "BAS short to supply voltage/open" and "IAT short to supply voltage/open" (expected). Note these are opposite of your codes - short to ground.

I would say with 95% certainty your ECM was damaged by the ratchet mishap. The final confirmation would be to unplug both ECM connectors and check the following ECM *harness* connector pins (at the end that plugs into the ECM) for short to ground. Leave the IAT and BAS sensors unplugged at the other ends.

Set your meter to the Continuity function (7 o'clock position). Touch both meter leads together and be sure you hear a beep (sanity test). Put negative meter lead on a good ground, and positive lead on the connector pins below, testing each one separately:
- Black connector pin 10
- Gray connector pin 10
- Gray connector pin 2
You should not hear any beeps, meaning the sensor wires in the harness don't have any short to ground. Again, you're checking the harness-side ECM connector, not the ECM's connector itself.

 

[foreignrider]

No beeping!