This past month my 99 vert M6 has thrown a couple of codes, and thrown each of them twice.

C1226 LF Excessive Wheel Speed Variation

C1281 Steering Sensor Uncorrelated Malfunction

I'm throwing them on separate driving occasions, so I'm assuming they are not related.

I throw C1126 when I come off the mark very fast, high revs, and perhaps get a tad bit of wheel hop as I switch gears. I'm hoping this is something I'm doing wrong and not an issue with the wheel sensor.

I throw C1281 always when I'm making a right turn, sometimes coming down a hill and turning to the right...

They're both history codes, I clear them, and move on. But I have thrown each twice and I'm wondering what I should do next. Any help would be greatly appreciated!

 

MadDog,

As far as the RF wheel speed variation code...could be one of three issues basically.

1)Bad Wheel Speed Sensor jumper wiring harness

2)Bad Wheel Sensor itself(VERY UNLIKELY)

3)Bad EBCM( UNLIKELY)

The first one is probably the issue 90 percent of the time. I wouldn't even begin to worry about an EBCM unless it starts throwing more codes.

First thing to do is get some diaelectric grease and put some on all of the connections for the wheels speed sensors and harnesses all the way back to the ones that are on the frame.(after blasting them out with electrical cleaner).

While they're disconnected(easier to do this with the wheels off) take a digital mulit-meter and measure the DC VOLT output of the little pigtail connection that comes out the back of the wheel hub(the sensor is inside of the hub). You're looking for between 0 and 5 volts DC signal depending on how fast the wheel spins.
Then check the resistance of the same connection. If it's between 850-1350 ohms...the sensors are working properly and all is good there.

Then re-connect everything back up and it'll probably take care of the C1226 code.

When you're disconnecting and reconnecting the jumper harnesses, pay close attention to the actual connectors inside where the male metal part actually "grabs" the female metal part. If they look messed up AT ALL, replace the jumper harness on which ever side.

Another quick way after you grease the connections to figure out if it is just the jumper harness....just switch the two side's(there's one jumper harness on each side that runs to each WSS). IF the code switchs to the other side....it's obviously the harness.

Sorry I can't help with the other code.

DZ

 

Thanks so much DZ! That is excellent trouble shooting advice! Still looking for some help with the other code, and trust me, I've already read the LONG posts on replacing the steering wheel sensor. Hope I don't have to go there!

PS: forgot to ask about how to FIND the wheel speed sensors and harness. NOt even sure what I'm looking for, LOL. Total vette noob here!

 

On the C 1226 code, check to see if the wheel speed sensor harness wiring is too close to spark plug wires. The code generally means electrical noise on the harness wiring due to routing too close to high energy ignition system components.

The C 1281 code indicates understeer or oversteer for 10 seconds or longer as measured by the vehicle stability enhancement system (VSES).

The C 1281 code is set when the VSES is engaged for 10 seconds with the delta velocity error always in understeer or oversteer. The VSES is activated by the Electronic Braking Control Module (EBCM) calculating the desired yaw rate and comparing it to the actual measured yaw rate. If the yaw rate error becomes too large, the ECBM will attempt to correct the vehicle's yaw motion by applying differential braking to the left or right front wheel.

Dont blame me. Much was quoted or papaphrased from the Corvette Service Manual.

 

Thanks, Jerboa. At least I know what the car was trying to do at the time! I wonder if just disengaging traction control would solve all my problems--except losing control of the car!

Do you think I should just "watch" this problem? I guess I can check that wire near the plugs, too!

 

I'd drive it the way it is for a while. Try to be sensitive to "brake pedal feel" during right turns. If the traction control is activating you should be able to feel a rapid pulsation in the brakes. This pulse is suppose to be much faster than the pulse rate if the ABS is operating.