At my wits ends: 2013 Stelvio Not Starting

[Kuni0]

Ordered a new set of plug caps. I'll report back on the results. Regardless, it's a good opportunity to learn my bike more.

It is funny that a bike that I consider I know so well throws me something out of left field, and one so well documented at that. (at least I haven't touched the 'sacred screw' in all of my meddling)

[pete roper]

I have done a useful video on throttlebodies I recommend you watch.

it covers some important stuff about the 50mm TB’s and the W5AM system.

[pete roper]

17 hours ago, gstallons said:

I have some NOS (old) Champion and NGK caps I inherited from a friend and have them laying around here. You can get them from any good bike shop . 

As I said. NGK have ceased production. The end! No more! Any at any shop will be NOS. I don’t know about Champion.

[gstallons]

The NGK caps are a part # LB05F . I think I put them on my red frame after dropping it in the Waffle Hut parking lot. 

[Pressureangle]

8 hours ago, pete roper said:

I have done a useful video on throttlebodies I recommend you watch.

it covers some important stuff about the 50mm TB’s and the W5AM system.

I thought the oil-sump air filter was a feature, not a bug.

[Kuni0]

I'm back with a report, and unfortunately, the new plug c aps didn't do the trick. I tried a couple of times with my battery booster, and still no dice. 

[Kuni0]

I cleared and re-read the codes on the Guzzi-Diag, and got these now. My shade-tree mechanic intuition says it might be a battery going bad, but I swapped in a 'good' battery from my 2016 FJ-19 and it still didn't start

[pete roper]

That’s a weird set of faults. The fact that it’s saying the phase sensor has failed is interesting. Didn’t you say the injectors are firing and the plugs are sparking?

[gstallons]

Does this "scanner" give you a live data stream ? For you to have this many codes , I would suspect a wiring problem . How difficult are these sensor connections to reach ? You should disconnect each sensor and get 5v ref. one one side of ea. terminal of each connector. I don't have a wiring diagram on a 2013 Stelvio so IDK how this is wired or color codes for the wires.

Also , Phil's ? about spark and fuel injector pulse . Y or N 

[Pressureangle]

I don't know the wiring particulars of this bike, or modern 'Guzzi scheme, but if it was your car I'd say that you have a hot wire shorted to the sensor circuit source wire. The sensor source is typically 5 volts out to the sensors on a common feed, with individual returns to be read to the ECU. That all the sensors read 'high' means that either every sensor has failed shorted at the same time, or that 12 volts has found it's way into the 5volt feed line. 
Has the ECU been unplugged recently? A bent pin can do this. 
You can test this theory by using your multimeter to read voltage at the sensor connector with everything else connected and the ignition on. 

Assuming they use the common 5v sensor scheme. 

[Kuni0]

9 hours ago, pete roper said:

That’s a weird set of faults. The fact that it’s saying the phase sensor has failed is interesting. Didn’t you say the injectors are firing and the plugs are sparking?

Yes, Both injectors are firing and both plugs are sparking

 

4 hours ago, gstallons said:

You should disconnect each sensor and get 5v ref.

1 hour ago, Pressureangle said:

You can test this theory by using your multimeter to read voltage at the sensor connector with everything else connected and the ignition on. 

That's something that I've already tested. I disconnected the cam position sensor from it's terminal and tested the connection to the ECU with (ignition on, testing Volts). From what I've found, the voltage should be 5V for the high and low signal. When I tested the terminal I got 1.5 and 2.5V. I unplugged the connectors from the ECU and it looks perfect (can't see any corrosion)

[gstallons]

Hmmmm . Somethin' ain't right ! Do me a favor and put a test light in one of the connectors and see if the (incandescent) regular test light lights up and gives you 5v ref. voltage w/your DVOM . Can you post your bike's wiring diagram on here and let everyone have a look ? That cam sensor should read 5v on one terminal of the connector.

[Pressureangle]

7 minutes ago, gstallons said:

Hmmmm . Somethin' ain't right ! Do me a favor and put a test light in one of the connectors and see if the (incandescent) regular test light lights up and gives you 5v ref. voltage w/your DVOM . Can you post your bike's wiring diagram on here and let everyone have a look ? That cam sensor should read 5v on one terminal of the connector.

Unwise to use a test light on a 5v reference circuit, the SMD in the ECU can be damaged. DMM only for safety. 

I went back and read the OP more carefully. There's this- 

'2. Check the ECU. When I check high and low signal from the batter to the ECU, I see 10V for both instead of the aforementioned 2.5 and 1.5 V. Is this significant and direct it down to my wiring harness? ' 

If I read correctly, your ECU is seeing only 10 volts? If that's the case, you have either a bad battery (asked and answered) or you have a failure in the circuit between battery and ECU. By now you must have tested cables and connections, yes? Voltage drop across all cables and connections in the circuit to find the drop. I don't know what's under the seat, but if it's a megafuse I had one that defeated the entire crew for an hour and me for a minute- it had blown, but the carbon tracing carried enough current to light up a test lamp, and the fault was only revealed by removing the fuse and visually seeing the blow. It passed all the tests in situ. 
Vehicle electronics typically self-protect at about 9.5 volts DC, and you're right on that margin.

[gstallons]

I have never had a problem checking for Vref using a test light and I've never suffered any problems. Now I use a DVOM when doing delicate things . 

 You do need 12v battery voltage to do any work you need to connect a battery charger or another full size 12v battery.

Edited 18 hours ago by gstallons

[Kuni0]

I performed the test in this video here (start of the test at 2:00 timepoint). Even though it's for a car, I don't see how it'll be much different for a motorcycle. 

Instead of seeing 5V for the high and low signal, I saw 2.5 and 1.5 V. I tested the ground per the procedure in the video and got exactly 12.6V