Possible Oil Sensor

Hello,

my beautiful 2017 1200 GRiSO died about 30 miles from home ...
It started showing the "SERVICE" warning with the red triangle occasionally for the past 2 months with engine OFF, always going away after turning ON.
Yet, today, the service warning did not turn off, bike started at 1 Cylinder... I was able to do about 1 mile and then died...

I can see
ECU Error 27,31 *Injectors 1,2 CC Ground
and
DSB 07 ( memo ) Oil sensor


Via Guzzi Diag I see
P0201 : to low
P0202 : to low
P0351 : to low
P0352 : to low

I presume it is the Oil Sensor... yet is it normal to have all the other codes -- and no starting anymore ???? Are the injectors 'grounded' for safety until the sensor is fixed?

I am just about to do a 11K Miles service maintenance ... I presume I will have to pull the tank... so I am thinking of changing the tank connector fitting..
Anything else suggested to be done at 11K miles with the tank off ???
Apart from the OEM oils sensor, I read about the BMW one? Do you have a part number or a thread pointer??

Thank you
Giuseppe

Oil sensor might be the cause of the 'Service' warning but is unlikely to be the cause of the no-run situation. Running on one cylinder is very often due to damaged plug caps. We're the valves checked at the break-in service? If so, by whom? And did they know how to remove the plug caps? You don't pull them off from the top, you lever them off from the bottom with a long, thin screwdriver stuck in through the cooling tunnel just above the exhaust manifold in the head.

If the plug caps are arcing to earth it can cause all sorts of odd problems and error codes to be thrown. If they check out though check the injector plugs carefully as it's the injectors that are being flagged as an issue.

Hi Pete,

What is really odd is that the bike was working perfect. I stopped for coffee after about a 40 miles ride in the mountains, and when I started it back up ( after 15 minutes ) I saw the service warning which stayed ON even when the bike was started. Then I noticed only 1 cylinder was going, well either that or it was going extremely bad and rough ( accelerating, the engine was staying at low rpms ), then it just died and I pulled off.

Bike has 9750 Miles and it had the last service done by a Moto Guzzi dealer at 5500, when they changed plugs as part of the 6K scheduled maintenance . Oil is fine . The bike just showed the "SERVICE" warning a few times before today either at low RPM or turning on the key with engine off, but it cleared right away.

OK so I have to troubleshoot the NO start first. The engine cranks fine. I saw the procedure to check the other codes in the service manual.. will be going through that.

What I find it really strange is that both the Oil Pressure Sensor AND the Injectors are throwing codes at the same time!... Maybe it is something electrical -- as you said -- that came loose somewhere or it is shorting.....

Thank you,
Giuseppe

Just remember. Be methodical. Start with the simple things. It's usually something stupidly simple.

Take the plug lead covers off and, in the dark preferably, look and listen for the spark jumping to earth around the bend in the plug cap.

Check the injector connections and try cycling them with Guzzidiag. If they appear to be working flip off a plug cap. Put a plug in it and ground it on the engine and spin the engine over. Do you get a spark? If not it might be the phase sensor although they don't usually throw a code.

Hi Pete,

Well! I started from the bases. I looked at the injectors, coil and fuel pump "C" fuse and it was blown!
I replaced it with a spare 15A, bike started but sputtered and died. Cranked again started for a few seconds, still did not sound right than died. Checked the fuses again and the "C" fuse was blown again!

So there is something shorting somewhere...

What is the main cause of that "C" fuse blowing that you know??

Will be continuing in the morning.. 930PM in California, and I don't want to do more damage than good.


--Giuseppe

Time to get the multimeter out I'm afraid. Tank off and start tracing the loom.

Put a call out to Kiwi Roy, he Yony and Beetle are the main electrical whizzes but I'd be looking for frayed cables either close to the injectors or up by the steering head for starters.

What else does that fuse control. It's not the speedo sensor one is it?

the manual says C - Fuel Pump, coils, injectors.
Now a while back I tapped off the crank sensor to the coil for a gear indicator..I will be checking that too
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Is the alternator working, just a thought
Does it crank ok?
This is the diagram for yours I think, the fuses are numbered not Lettered.
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Please try and identify the fuse that was blown on this drawing.
F3 or F4 will stop the bike, my first thoughts are you have an excessive load pulling the Voltage down.

It certainly won't run if the pump fuse is blowing.
I helped a guy out not too long ago he had a short in the speed sensor cable (48), but that would be fuse 4 I think.
It was such a small wire it would only blow the fuse after a few minutes but it was able to pull down the Voltage to the ECU.
Theres a connector up under the tank somewhere it can be unplugged.

I have attached a link to the earlier 1100 schematic, the fuses there were lettered
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My tiny little reptile brain was thinking speedo sensor as a possibility but I tend to grunt it, Roy is smart.

I think it might be something pulling the Voltage down on pin 17 of the ECU hence the Alarms.
The speed sensor is what I'm leaning towards as well, with its little bitty wire it can pull enough current to pull the Voltage down but has trouble blowing the fuse.
If you trace the Red/Black wire coming from relay 28 it also goes to the Lambda probe heater that's another possibility.
If you look at relay (29) there's not much there that could draw a lot of current unless there's a short in the pump
Scagliog, is the speedo acting normally, any unusual noise from the fuel pump, anything else no matter how unrelated it seems?
When you get back to troubleshooting turn the key on but don't try to start it for 10 minutes, relay (28) will close powering up all the stuff on the red/black wire, any alarms or fuse blowing in that stage?
Relay (29) will close for a few seconds then open again so there will be no load on it after priming.

If Roy is right just disconnect the speedo sensor, (Right hand side behind the footrest hanger plate just behind the battery.) stick a fuse in and see if it works. The speedo won't but the bike will run.

Speedo sensors are cheap and easy.

Morning gentlemen!

The bike is blowing what is truly labeled Fuse "C", 15 A, which the manual says it is for Fuel Pump, coils, injectors.

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In fact, on the wiring diagram you can see the coils the injectors and the fuel pump positive going to the secondary injector rely (29) to the Fuse F3 -- which I think is labeled wrong on this diagram since it says 3A, while that 3d Fuse is 15A at least on my 2017.  

Shouldn't the short/high draw be only from injectors coils or Fuel Pump??? Like a bad coil???

Alternator seems fine -- again the second fuse lasted a few seconds (maybe 10) with the bike still not running right.


Could it be in fact a bad coil that is not sparking properly a cylinder and then blowing the fuse for the the other too???

BTW -- the Oil Pressure Sensor still shows ACTIVE so I will have to deal with that as well.

Thank you,
Giuseppe

So we have a conflict between the diagram and reality, could you unbolt the fuse holder and verify the wire colours going to that fuse.

Hi Roy,

see attached picture from a wiring diagram that I got a while back -- it properly shows 15M Fuse "C" from Coils Injectors and Fuel Pump, third from the top. Maybe this is an updated diagram for the last series 1200SE 8V

-- How do I attach a file? If you give me an email I can send directly
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Thank you,
Giuseppe

Thanks for posting the schematic, I probably have a copy of that somewhere. If that is truly the case there's not a lot to troubleshoot, unplug the 29 relay, unplug the pump and you can test the wires with an ohmmeter to chassis, the other side of the coils is only grounded by the ECU, that whole circuit without the pump plugged in should be open to chassis.
The pump will be quite low in resistance but you can measure the current it draws by poking the leads of an ammeter into the relay socket. 4 - 5 Amps, do that with the key off.
If looking for a short I often substitute a headlight bulb with both filaments in parallel for the fuse, that will supply enough current to supply the load but a short will make the bulb flash.

When you turn the key on the only load on relay (29) should be the pump for a few seconds, the ECU won't fire the coils or the injectors because the motor is not turning


The reason I was suggesting the speed sensor, its pretty flimsy wiring compared to the injectors etc and there are lots of potential pinch points
Theres's 10 x the amount of wiring on relay (28).
Without a 1200 to look at I probably can't help you any further so good luck, be sure to post back what you find.

Hello,
Got the bikes opened up... checked for continuity all red/brown to the 29 relay -- injectors, coils, fuel pump, all show 0.1 ohms.

1. Can the problem be somewhere else THAN the Injectors, Coils and fuel pump ?

Now I noticed that the fuse blows even with just the key...

Giuseppe

Have you tried unplugging the speedo sensor yet?

I need to go get a pack of 15A fuses... I run out...

As far as the speed sensor... I tapped into that as well when I installed the gear indicator. Easy to unplug now with all the sides and the tail off..

Giuseppe

Thats another advantage of using a lamp as a substitute fuse, it will never blow, most electricians will never try to troubleshoot a short using fuses.
You shouldn't have tapped into the +12 Volts of the speed sensor but may have.
I think you said the fuse is blowing before you press Start

Well folks! With my last 15A fuse before going out.. I disconnected the speed sensor and plugged all back in..
Bike started and seems normal -- except the Service warning for the oil sensor.

So that is interesting to me that I am blowing that Coil fuse for something fried in the speed sensor??

You guys are awesome! I would never have thought!

I need to further debug the speed sensor now... I need to figure out what went bad in the wiring.
BTW the speedometer was working just fine, never saw any issues...

Grazie!
Giuseppe

So about 1 year ago I tapped + and - from the tail lights, and I tapped speed sensor signal and crank shaft signal from the right coil to go to the gear indicator. All worked fine....

Cheers
GIuseppe

If you are just picking up a signal I usually tap in using a resistor to limit the possible current to say a few milliamps e.g. a 1K resistor. That way you cannot kill the ignition or whatever.
The resistor will be the first thing in line, if it shorts to ground downstream it cannot short out the original circuit.
I think you might find you have a short in your gear indicator, anyway i'm confident you will find the problem shortly.

yes sir! the wires to the gear indicator got crashed....now I don't see any codes anymore...not even the dashboard07..but I still have the service warning and the red triangle.
do I have to reset something??
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Try clearing the faults in the dash. If it persists then the pinched wires must be the culprit. Just disconnect the gear indicator for now and see if the problems disappear.