Code 12 troubleshooting

[Jdreed81]

I have a 2008 nytro.. I was on vacation last week and it was running fine to start the week..woke up one morning went to start it and it flashed code 12 and wouldn’t start.. I assumed it was froze up as the temps dropped to below zero.. I put my portable ice shack over it turned on the heater and thawed it out for a few hours... she started slowed but fired up.. went for a nice ride and things seemed to be good.. the next time I went to fire it up it would not idle I had to throttle it to keep it running once it got warm it idled fine.. the following day started hard again once it was warmed up it ran fine the rest of the day until that evening when it left me stranded.. now it flashes 12 will crank but won’t fire.. I’m in need of some expert advice as I was at my local dealer today and they couldn’t even tell me where the crank sensor was or how to diagnose it let alone the price of a new one..thanks in advance

 

[74Nitro]

You have to remove the right side engine cover. It mounts beside the flywheel. These are available separate from the stator if you buy aftermarket, but not from Yamaha.
Get a gasket also.

 

[grizztracks]

The 2008 Nytro is Fuel injected so the pickup is not in with the stator like the carb's engines. The crank sensor is located on the left lower side of the engine near the oil filter. They run around $80-90 (#8GL-81670-00-00). It sound like you may have a battery or starter issues. Load test the battery and check for corrosion around the starter relay connections. Also check the wire harness under the steering post and behind the primary clutch for possible damage due to rubbing. The ECU expects to see a signal from the crank sensor anytime the ignition key is turned to the start position so if the engine doesn't spin when attempting to start then Code 12 will display. There have been reports of failed crank sensors but if the engine doesn't crank over properly during a start attempt I'd address that first.

 

[Jdreed81]

Thanx guys I’ll dig into it during the week and let you know what I find.. I replaced the starter last year so I hope that’s not it

 

[74Nitro]

The 2008 Nytro is Fuel injected so the pickup is not in with the stator like the carb's engines. The crank sensor is located on the left lower side of the engine near the oil filter. They run around $80-90 (#8GL-81670-00-00). It sound like you may have a battery or starter issues. Load test the battery and check for corrosion around the starter relay connections. Also check the wire harness under the steering post and behind the primary clutch for possible damage due to rubbing. The ECU expects to see a signal from the crank sensor anytime the ignition key is turned to the start position so if the engine doesn't spin when attempting to start then Code 12 will display. There have been reports of failed crank sensors but if the engine doesn't crank over properly during a start attempt I'd address that first.

Thanks for the correction Grizztracks.

 

[Jdreed81]

Well I checked all connections on the relay replaced the pick up sensor without any luck... I also put a new battery in.. I am concerned it might be the fuel pump.. I suppose it could be the ECU as well.. not sure where to go from here.. thanks for the help guys just thought I’d give y’all an updated date and maybe see if you had any other ideas

 

[74Nitro]

Well I checked all connections on the relay replaced the pick up sensor without any luck... I also put a new battery in.. I am concerned it might be the fuel pump.. I suppose it could be the ECU as well.. not sure where to go from here.. thanks for the help guys just thought I’d give y’all an updated date and maybe see if you had any other ideas

If you still have code 12, pull the big plug off the ECU and locate the 2 wires that go to the crank sensor in said plug. Test them there and you should get the reading of the crank sensor.

 

[Jdreed81]

Tested the wires.. found out one of the wires was bad jumped The wire and it fired up.. buttoned it up and now it throws a hand full of codes but not code 12.it started once but will not start again... it’s throwing codes 13,15,22,23,25,43,84.. did I fry the ECU.. I was told I might need to reprogram the ECU... wow I’m get frustrated... I really appreciate all the help 74nytro and grizz have given.. y’all are top notch

 

[grizztracks]

You need to check the wire harness. It sounds like either a bad spot in the harness or possibly a bad ground splice in the harness. Under the steering post and behind the primary clutch are the two problem spots for rubbed through wires. Anytime I've had multiple codes it ended up being a burnt ground splice. The splice looks like a connector with nothing plugged into it. All the wires come in from one side and are connected with a metal strap in the plastic. I've seen these overheat and melt the connection several times.

 

[74Nitro]

Yes, what grizz said. Don't think there is anything wrong with ECU. remember that anytime parts of the harness are unplugged the ECU will recognize an open circuit and throw codes. Look for the finger connectors that are located in multiple places in the harness and clean the fingers. They are square or rectangle blocks and have all the same colour wires coming into them. But as grizz said, if you have that many codes most likely one of the ground connector blocks. Supply a ground right from the battery to the ground connector block. Ground(or negative) wires are always solid black colour.

 

[grizztracks]

rub point on engine mount behind primary

Rub point under steering post bushing

 

[Jdreed81]

Thanx guys.. I’m off Friday I’ll be getting after it.. we just got 20 inches of snow and know I’m dying to get out ... I’ll let you know what I find