fault code 12-crank sensor on gen II

Three times lately, the red abs light and MIL amber light has come on for a short time. Once leaving a signal light, it was on for about 200 feet and the engine ran very poorly. It won't run without a crank sensor, so I could be walking soon!!!

I am learning about pulling codes. Diagnostic code 60 was zero for EEPROM fault codes, 61 D.C listed fault code 12(crank sensor) and 62 history erasure was 1. I cleared the code with the kill switch so 61 and 62 are now zero. Now to fix the problem.

The Yamaha manual poor locator diagram shows the crank sensor on the left front of the engine somewhere?? I can see it. Does someone know exactly were it is? Does a lot of plastic need to be removed? I am trying to ask first instead of disassembling more than I need to.

I installed a Audiovox cruise about 3000 miles ago, which works fine. Is it possible the gray, blk-blue wires for the crank sensor goes up over the fuel rail and I created a problem top side?

Any help is appreciated.

Lower Right hand side of the engine under the rectangular cover forward of the clutch cover...good luck.

Thanks un4gvn for the location. I pulled the right side plastic and the gas tank to inspect the crank sensor wires and perform an ohm test. The connector for the crank sensor is down under the throttles where you can't get without a lot of work, so I pulled the connector at the ECU. The ohm value was right at 500 where it should be between the gray and black-blue wire. However, this means nothing when it gots hot and has a glich. Will drive locally today for a salad run with the guys and see what happens???

Well especially with small coils like your crank position sensor, te resistance can change whith heat. If you continue to have problems you may want to remove the side cover and inspect it. Also, the problem might be with the stamped out rotor that feeds the CPS its position, I would check that as well, may be as simple as the bolt that holds it to the end of the crankshaft has backed out a little. Good Luck!

I'm having the same problem with my 07. Code 12. I didn't get much time last night to disassemble a lot of shit, just enough to see that the plug in connector is hard to get to. I think I will check it at the ECU like you did.

I did see in the wiring diagram that the blue/black wire goes to "coupler 3" which is item# 32 in the diagram on page 8-62. So as best I can tell, if I unplug the connector at the ecu and check the resistance value there, then the coupler#32 resistance value will be included in the number.

In the diagram on page 8-61 item #43 is the crank position sensor. You can follow the wires and see that the gray goes straight to the ECU; BUT the b/l wire is tied into coupler 32. So I am hoping that there is a connection issue there, rather than the connector that is burried under the air box..

Here's another question: on page 8-227 "checking the crank position sensor" it shows it as black and gray; but in the wiring diagram on page 8-61 it shows the colors as gray and black at the sensor then changes to gray and black/blue. So now I'm not sure if the plug I was looking at last night is even the right one. The wires looked like they were white and black.???

If someone with a FSM could refer to the pages I indicated, and give me their thoughts I would be forever in your debt.

The two wires from the sensor to the disconnect plug under the throttle bodies are black and gray.

The two wires from the disconnect plug to the ECU wiring harness plug are black/blue and gray.

The black/blue is a common wire to several sensors. The gray wire is the signal wire to the ECU.

The sensor circuit DC resistance should read in the range of 421 to 569 ohms at 68 DegF.

Are you sure this is an ECU engine error or could it be an AE shifting system error or possibly an ABS system error?

Are you sure this is an ECU engine error or could it be an AE shifting system error or possibly an ABS system error?

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AE shift codes are formatted differently, ABS will have a flashing ABS light. At least in Daily Commuter's case his engine will not crank due to the crank sensor error -- which is correct per the FSM.

Having two rare crank sensor errors suddenly happen at nearly the same time gets your attention. FWIW, Daily Commuter still has the original ECU, he hasn't done the recall swap yet.

It is easy to unscrew the ignition timing test hole (giant slot head screw looking thing) and check to see if the gear is not loose. The sensor is at the bottom of the gear, dunno if you can slip something in to see if it is loose. There is a maximum gap between the senor and the gear, once exceeded the sensor will no longer work.

If heating of the sensor was the sole cause of the failure it would run when cold.

If everything ohms correctly at the ECU connector, the harness and sensor would be OK. That leaves the ECU being defective, timing gear being loose or the gap between the sensor and the gear as candidates.

Constant Mesh said:

The two wires from the sensor to the disconnect plug under the throttle bodies are black and gray.
The two wires from the disconnect plug to the ECU wiring harness plug are black/blue and gray.

The black/blue is a common wire to several sensors. The gray wire is the signal wire to the ECU.

Click to expand...

Ok so if there were a problem with the black/blue wire I would get more error codes wouldn't I?

So I will have to go after the gray wire.

I'm going to have to pull the fairings, and probably the airbox to get to the connector down by the throttle bodies. That sucks! What asshat out a connector plug where human hands can't reach it? Jeeez!

Any other suggestions instead of my plan here? I'm not looking forward to this. Probably not as bad as I think, just time consuming.

Only slightly easier, pull the connector off the ECU and ohm between the Gray & Blue/Black wires in the connector. Take care not to damage the pins! The readings should still fall between 420 and 570Ω. This will show if the sensor is statically good but won’t indicate anything about the sensor to gear gap.