| Author | Message | ||
     Pyrogen |
This is on a 2009 1125 R with about 40k miles on it only elec mod is the EBR "race" ecm. What all info does the C.A.N. bus communicate between the ECM and I.C.? The elec. manual says VSS info and tach info as a few examples but doesn't mention anything else. I have a historic code: Comm error U0001. My speedo/ trip/ odo/ gear ind. don't work. I swapped the VSS out with one in bad physical shape(wires coming out of the sensor were previously/poorly soldered as a repair), from some big twin harley and all that stuff worked til engine hit operating temp, so I ordered a new 1125R VSS from Harley. I also noticed that my ambient temp displays an initial reading but doesn't change or adjust. Example: This morning I got on the bike in my garage, it read 55 deg F. I know it was around 35 deg F. outside, but it read 55 deg F. the entire trip to work, which is about 40 miles. It use to give an initial reading(garage temp) and then after a few minutes change to ambient and then fluctuate with outside temp. I wonder if the sensor is dirty and should be cleaned. How do I clean it without damaging it? As near as I can tell everything else in regards to the I.C. appears to work fine. I question the mulit meter I have, I tested the C.A.N. resister and got 0 ohms, I know it should be 120 ohms but until I get the chance to test it with a known working ohmmeter I assume the resistor is fine. Besides if the comm error was reoccurring, I would have a CEL, right? Thank you for the help. | ||
| D_adams |
Might be a broken pin on the back side of the IC, seems like I'd heard of a couple breaking/failing in the past. Might check that out, could just be a loose connection. | ||
| Two_seasons |
If the CAN bus isn't working, or it's disconnected, I believe you will see a THEFT ERROR on the display. CAN bus talks between the ECM and the display. Just a "highway" for data comm. | ||
| Zac4mac |
VSS and AT sensor are related. The AT sensor will start with the temperature it sees at key-on. After some distance(a mile I think) it starts live updating. If the VSS isn't working, it thinks it never went the mile... Z | ||
| Pyrogen |
Ok, after reading the elec manual more, I figured out why I am not getting IAT display past the initial reading. Like what Zac posted there is a relationship between the two sensors. The bike must maintain 25 mph for 1 minute for IAT to update to the display. I do not have a signal from the Vehicle Speed Sensor(VSS), therefore the bike does not know it is going 25 mph and therefore does not update IAT info. Also, as near as I can tell the CAN bus normally communicates security info, speed, distance, gear pos., tach., neutral pos., CELs, intake air temp, and engine coolant temp. It probably communicates more but I haven't seen anything else in the manual. I am double guessing root cause for lack of VSS signal. I worked through the troubleshooting flow chart in the manual w/ exception of using the signal generator across pins B & C on the connector where the VSS harness mates with the main harness, with passing results for all other tests. This lead me to believe its the sensor that is bad, but shouldn't I be getting a CEL and a DTC code for no VSS signal? I would figure that 0 signal would be considered "low" signal and therefore it should give a CEL and DTC P0502. I do not even have a historic VSS DTC of any kind. I tested CEL function by pulling fuel pressure sensor connector and I got a CEL and now a historic DTC for that. Also, in diagnostic mode, toggling through parameters, the result for VSS is 0, the manual says that it should either be 0 or 1, but does not specify the relation of the two results, Do I assume that 0 = no signal, 1 = signal? Rolling the bike back and forth does not change the result. Any additional thoughts would be most helpful, thank you in advance. (Message edited by pyrogen on December 11, 2012) | ||
| S21125r |
Pyro, Not sure if you've ever used Tuner Pro or ECM spy, but you can get live data with either of those two tools. Since your plugging directly into the ECM with the serial cable, I suspect you might be able to confirm/deny a CAN com error between the ECM and Cluster. i.e. if your Tuner Pro live data shows VSS fluctuating but your cluster isn't then you probably have a com issues. On the flip side if Tuner pro isn't showing VSS changes then the issue lies somewhere between the sensor and the ECM. Possible grounding issue maybe? | ||
| S21125r |
Pyro, Looking through electrical manual description of the VSS, it says it get battery voltage from the brake/horn circuit and that the output frequency varies with speed. What confuses me is the blurb about "output voltage from the sensor is 5V per increment of of distance traveled." Not quite sure what that means but almost sounds like the sensor is taking in 12V and putting out pulsed 5V. If that is correct then perhaps P0502 means output is zero volts (shorted to ground) and P0503 means output is 12V (shorted to supply). If you don't have either of these DTC's then might be that your VSS is outputting 5V like it should but it's just not "seeing" the trigger wheel to set the frequency. Seems plausible that it would be hard to set a DTC in that condition because it's more of a mechanical failure and you have no other inputs to look at to set a fault. | ||
| Azxb9r |
Just to clear things up a bit on the CAN Bus, CAN is a communication protocol, and the Bus is the circuit that communication takes place on. CAN uses a two wire circuit with voltage pulses transmitted on both wires. If either of the Bus wires is shorted to ground or voltage, the Bus will be dead. The best way to test the CAN Bus is with a DSO. Communication errors will set a code but they will not always illuminate the MIL. CAN communicates using a 2.5v bias. CAN high(CAN+)pulls voltage up from the 2.5v bias to 3.5v and CAN low (CAN-) pulls the bias down to 1.5v. The communication occurs at too high of a speed to capture on a DMM, but you can just look for voltage between 1.5v and 3.5v on the two wires to get an idea if the Bus is alive. If you have access to a DSO, you can actually see the communication taking place...you have no idea what it is saying, but knowing it is capable of communicating is all you need to know. | ||
| Pyrogen |
on page 6-71 it shows a DTC P0608 but I can't find anywhere else that it states that code or goes into any details. S21125r - So in summary of your assessment, If the white wire going to the ECM isn't shorted to gnd, nor is it shorted to 12v then it is within spec and no error code is displayed, then I should be looking at the ground wire not making good contact somewhere? is that pretty much what you're saying? Which the ground wire runs through 2 connectors and then splices with the ground for the BAS and DLC, most likely very close proximity to the ECM that the ground wire goes to after the splice | ||
| S21125r |
Pyro, That is my guess anyway about what the two DTCs mean and maybe why you don't see them - not saying I'm right though as I'm looking through the same manual you are and scratching my head :-) My comment about the ground is one that always seem to apply to most things electrical - when in doubt, suspect a ground. I would think a few continuity checks between ECM pin 19, the VSS pin C, and frame would answer that question. BTW I'm assuming your Horn and brake lights work - correct? My suspicion is that maybe the pickup on the sensor itself might have crud or iron fur on it and is preventing it from reading the trigger wheel properly. Again just my guess but I recall seeing a few threads on here stating that very thing happening. P0608 is an OBDII compliant DTC. A google search shows a couple of different descriptions for it but in general sounds like a VSS Output check has failed. | ||
| Two_seasons |
When VSS is dirty, either clean or replace. The sensor collects small metallic particles. | ||
| Pyrogen |
I will check the grounds tonight if I get time. I did check the main grounds at the steering head and the one holding the fuel pump cover. I tested through the troubleshooting flow chart with the exception of putting the 144hz to the ECM and everything tested good. Yes sir, horn and brake light are working, I tested those first thing. Do you guys think that there are DTCs that set but don't show up in the diag mode on the I.C. and can only be read by the dealer? When I first experienced the lack of speedo, I swapped the sensor out with one that a friend had laying around, it had suspect repairs to the harness but rolling the bike around I got speedo display, however I barely got down the road before the speedo became erratic and then quit again. The whole time I was watching for a CEL but never got one, I also checked for DTC immediately after I got home and had just a comm error and it was historic. Oh, well, hopefully when the new sensor comes in that it fixes my problem. | ||
| Pyrogen |
The VSS came in this last weekend and after installation and 3 days of testing(riding back and forth to work) I think I can say its fixed. Everything appears to work correctly again. It still puzzles me that the other one quit working but did not cause a CEL or DTC. | ||
| Froggy |
You will only get a CEL/DTC if the wire is shorted. Simply disconnecting it or even breaking the wire will not cause it to happen. |
