The Chicken Man
Well-Known Member
Fault code No. 12
According to page 8-4 of the service manual:
Item: Crankshaft position sensor: no normal signals are received from the crankshaft position sensor.
Fail-safe System: Unable to start engine, Unable to drive vehicle
Reinstatement method: Cranking the engine.
Has anyone here encountered this fault code before? And if so, what symptoms did you experience? How did you fix your issue?
I've read other people mentioning this code in comments on other threads, some stating they replaced their stator & sensor assembly. But I'd like to start a dedicated thread to this issue to leave some info behind for future readers.
My experience:
My bike is a 2009. I've owned my bike for about 3 months and 700 miles now. Sunday, 7/30/2023 I drove my bike across to town to a friend's shop to help them work on their truck. Went to go leave and encountered this issue. The bike would power up normally when I turned the key on, but when I would press the start button it would not crank. A clicking sound could be heard each time I pressed the start button (I assume the starter relay) but the bike would not attempt to crank. Additionally, every time I would press the start button the engine light and abs light would illuminate for as long as I held the button but would turn off when I let off the button. However, if I held the start button for several second the engine light would start to blink, then once I would release the button the engine light would stay on. Once the engine light was on, the diagnostic mode would show a single code, code 12. I could clear this code and replicate this process. I was stranded.
I spent the afternoon, tearing into the bike. I knew the code was for the Crankshaft Position Sensor, but I didn't have my service manual to check where it was located. So, I returned today with information in hand. The service manual gives instructions on how to check this sensor in section "Checking the Crankshaft Position Sensor" (page 8-132), which basically consists of unplugging the connector to check for continuity and measure resistance across the two wires (192–288 Ω at 20°C/68°F). Pages 2-55 and 5-4 indicate that the connector for the crankshaft position sensor is located behind the engine on the left side of the bike. I found mine sandwiched between the fuel tank and the heatshield behind the engine. See the below photos.
Has anyone tested their sensor before? My issue is that this connector's location makes it nearly inaccessible. The heatshield does not appear to be removable from the front so my only thought is that the fuel tank must be removed to access it. That seems like a lot of work for something that needs to tested for diagnosis. I'm curious how others may have done this.
Luckly for me, my issues went away as suddenly as it appeared. When I saw how hard it would be to access the plug I decided to see if maybe my bike might just start, and it did! I cleared the existing code and it has not come back yet. It's possible I inadvertently fixed my issue while doing all the digging around in my bike that I did, but I'm skeptical of that. I know this could just be a fluke, but my concern is that this issue could come back again. I fear this could become an intermittent issue and that it may leave me stranded somewhere far from home.
The fail-safe condition the service manual mentions implies to me that a no crank condition is normal/is what should occur when this fault is detected. But I do not have any confirmation of what caused the fault. Perhaps this is the early signs of the crankshaft position sensor going out? Do you think it is type of component is one to fail slowly/intermittently or would it more likely just quit all at once? Or maybe this issue is being caused by something else entirely. What are y'alls thoughts?
NOTE: I have not experienced this issue or any like it before. I also saw no corrosion or damage to any wire or connectors (at least those that I could see).
It's a pretty expensive part and the wiring seems like it will make it a tough one to replace, so I don't know if I can justify replacing it just for the sake of calming my nerves. I have a new larger fuel tank that will be installing eventually, so if I can verify that there is an issue with the sensor first that would be a convenient time to replace it.
https://www.partzilla.com/catalog/yamaha/motorcycle/2009/v-max-vmx17yb/generator
According to page 8-4 of the service manual:
Item: Crankshaft position sensor: no normal signals are received from the crankshaft position sensor.
Fail-safe System: Unable to start engine, Unable to drive vehicle
Reinstatement method: Cranking the engine.
Has anyone here encountered this fault code before? And if so, what symptoms did you experience? How did you fix your issue?
I've read other people mentioning this code in comments on other threads, some stating they replaced their stator & sensor assembly. But I'd like to start a dedicated thread to this issue to leave some info behind for future readers.
My experience:
My bike is a 2009. I've owned my bike for about 3 months and 700 miles now. Sunday, 7/30/2023 I drove my bike across to town to a friend's shop to help them work on their truck. Went to go leave and encountered this issue. The bike would power up normally when I turned the key on, but when I would press the start button it would not crank. A clicking sound could be heard each time I pressed the start button (I assume the starter relay) but the bike would not attempt to crank. Additionally, every time I would press the start button the engine light and abs light would illuminate for as long as I held the button but would turn off when I let off the button. However, if I held the start button for several second the engine light would start to blink, then once I would release the button the engine light would stay on. Once the engine light was on, the diagnostic mode would show a single code, code 12. I could clear this code and replicate this process. I was stranded.
I spent the afternoon, tearing into the bike. I knew the code was for the Crankshaft Position Sensor, but I didn't have my service manual to check where it was located. So, I returned today with information in hand. The service manual gives instructions on how to check this sensor in section "Checking the Crankshaft Position Sensor" (page 8-132), which basically consists of unplugging the connector to check for continuity and measure resistance across the two wires (192–288 Ω at 20°C/68°F). Pages 2-55 and 5-4 indicate that the connector for the crankshaft position sensor is located behind the engine on the left side of the bike. I found mine sandwiched between the fuel tank and the heatshield behind the engine. See the below photos.
Has anyone tested their sensor before? My issue is that this connector's location makes it nearly inaccessible. The heatshield does not appear to be removable from the front so my only thought is that the fuel tank must be removed to access it. That seems like a lot of work for something that needs to tested for diagnosis. I'm curious how others may have done this.
Luckly for me, my issues went away as suddenly as it appeared. When I saw how hard it would be to access the plug I decided to see if maybe my bike might just start, and it did! I cleared the existing code and it has not come back yet. It's possible I inadvertently fixed my issue while doing all the digging around in my bike that I did, but I'm skeptical of that. I know this could just be a fluke, but my concern is that this issue could come back again. I fear this could become an intermittent issue and that it may leave me stranded somewhere far from home.
The fail-safe condition the service manual mentions implies to me that a no crank condition is normal/is what should occur when this fault is detected. But I do not have any confirmation of what caused the fault. Perhaps this is the early signs of the crankshaft position sensor going out? Do you think it is type of component is one to fail slowly/intermittently or would it more likely just quit all at once? Or maybe this issue is being caused by something else entirely. What are y'alls thoughts?
NOTE: I have not experienced this issue or any like it before. I also saw no corrosion or damage to any wire or connectors (at least those that I could see).
It's a pretty expensive part and the wiring seems like it will make it a tough one to replace, so I don't know if I can justify replacing it just for the sake of calming my nerves. I have a new larger fuel tank that will be installing eventually, so if I can verify that there is an issue with the sensor first that would be a convenient time to replace it.
https://www.partzilla.com/catalog/yamaha/motorcycle/2009/v-max-vmx17yb/generator
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