CODES:

TCS - C1226 & C1225
A0 DCM - B2262, U1064, U1096
A1 RDCM- U1064, U1096
BO RFA - U1255H, U1096, U1064, U1016 (maybe U1061 I may have transposed the #)

I've been having problems with my traction control system, after running a while (no specific time sometimes 20 min sometimes 1 min) it's throws a code and shuts down the ABS and the TCS. (so it sounds like a short). I'll post the code after work today.

BTW The system does reset after the key is turned all the way off, but its a pain in the *** to have to shut down the system to get back the TCS.

I've replaced the wheel sensor. The code specified the drivers front wheel speed sensor, which is the hub/bearing assembly. Excited to fix the problem I replaced both front assemblies.

But it didn't work. I messed with the wire pins on both ends of the wire leading from the harness to a connector to a wire to another connector to the wheel speed sensorto make sure there was contact. everything looked good and tested positive for conductivity/resistance with the ohm meter.

It looks like these wires go behind the engine running w/ the brake and fuel lines. I would need to remove the engine to trace it.

Does anyone know where these things end up so I can try conductivity on the home run?

OR
Is there a way to splice in new wires from the wheel speed sensor to the TCS module to try to bypass the presumed short? (No I'm not removing the engine to trace a wire)

Are there any tests I can run for voltage/ conductivity before and/or after the code is thrown?

HELP!!!!

thanks

 

Put out the bat signal for Bill Curlee he is wizard of electronics and electrical problems on the C-5. Good luck

 

In addition to any codes, please include the year of the car and the mileage.

 

97, 6 speed, 48k mi

code to come

 

Any one of these codes??

DTC C1273 TCS Master Cylinder Isolation Valve Malf
DTC C1274 TCS Prime Valve Malfunction
DTC C1276 Delivered Torque Signal Circuit Malfunction
DTC C1277 Requested Torque Signal Circuit Malfunction
DTC C1278 TCS Temporarily Inhibited By PCM


Are you sure you are not troubleshooting a powertrain control module (PCM) problem?

 

Codes posted

HELP!!

 

DTC C1226 RF Excessive Wheel Speed Variation
I have the whole wiring breakout, and a 10 step diagonostic breakout with 10 troubleshooting steps if needed.

DTC C1225 LF Excessive Wheel Speed Variation
Same as above.

Circuit Description
The speed sensor used on this vehicle is a single point magnetic pickup. This sensor produces an AC signal that the EBTCM uses the frequency from to calculate the wheel speed.
Conditions for Setting the DTC
The DTC can be set anytime the brake is not depressed and no wheel speed sensor hardware DTC(s) are present, and the EBTCM sees a wheel speed variation of more than 14 Km/h (9 mph) for 2.5 seconds.

DTC DCM B2262 Horizontal Position Sensor Circuit - Left Power mirror - dont think that is your problem

Call me.

 

talk to you soon, going to granger, then to happy hr at tgi fridays at world gate for a little bit.

Thanks

 

Check your email. I sent the left front wire diagram.

 

DTC U1064 Lost Communications with BCM
DTC U1096 Loss of Communications with IPC


Most all of the codes you sent were somehow related to the loss of communication with BCM or IPC. All mentioned that in the first line of the description.

if you Spin the wheel, use a ohm meter to measure the AC voltage across the wheel speed sensor. If the AC voltage measures greater than 100 mV the sensor is OK. Be sure none of your wires are routed to close to your stainless steel brake lines as it could cause noise on the pair of wire, causing the computer to recognize a different voltage.

 

I seriously doubt that you have a SHORT! There are procedure in the trouble shooting procedure to check for resistance, shorts and opens. You will almost NEVER need to replace the wheel speed sensor unless the wires are compromised or the wheel bearing is damaged/worn. The sensors are pretty bullet proof:





Most of the problems with the wheel speed sensor circuit are female connector issues. The female pins get week and make crappy contact. Slight vibrations will cause a loss of signal and a code. On the front wheels there are a jumper harness that typically gives the most problems:





You should make ALL measurements at the main EBTCM connector. (you will need some one to help you. Read pin to pin at the main connector on the pins for a wheel sensor. You can read resistance, AC Voltage and read each wire to ground.







The faster you spin the wheel, the greater AC voltage you will see!

You will need to have some one shake the wiring harnesses while you measure resistance. Any variations in resistance readings while shaking the harnesses is BAD!

BC

 

I think you need to really examine you female connections.

Here is an example of a good and BAD female connector



I insert a male pin in the female connector. If the female pin grips the male pin with a good tight fit,, its good. If the pin is loose or just falls out, the female connector pin is BAD. I would resist cutting the connectors out and if you do,,,you MUST solder the wires together!!

BC

 

Thanks Bill Curlee, THE SAGA CONTINUES.

Here's what I've tried so far and the results. As you suspected the female connectors looked questionable, so I manipulated the spring to have a better connection.

After 35 miles and no problems on my way to Summit Point for a HPDE for the weekend, I hit a section of asphalt that was rippled (poor paving). Sure enough, my dash lit up like a Christmas tree. No TCS, NO ABS. Code TCS - No Comm

I ran the car anyway. The first day I locked up the fronts a couple of times. I went home and stripping off the plastic connectors, which just left the metal connectors which I soldered together. I insulated them with electrical tape (painfully time consuming), and zip tied them to the clips which I put in the original mounting position so all was secure.

The next day, after working past midnight after a track day 2 nights in a row, all systems were go untill I went into the fifth turn with a little dip in it and it was Christmas tree time again . I ended up flat spotting both brand new gs-d3 front tires (awsome).

At first it was just throwing the variation in wheel speed codes, but by the end of the day it was saying there was no com to the TCS.

This all started happening when I changed my headers. Then, because of the code, I thought it was the wheel speed sensor, so I replaced both ($400). Also I put new tires ($300) on because the others were almost worn out and I flat spotted them b/c the TCS cut out the ABS b/c of whatever problem I'm having. Not mentioning the time I've spent and not being able to enjoy my car, this gremlin is eating my lunch, literally.

When I put the new tires on the front they were both 255 40 17 in place of 245 45 17. But I figured this wasn't a problem b/c it started happening before the new tires went on.

Any more Ideas, a bad TCS module?
Do the new wheel speed sensors need to be synchronized?
Would a different tire size throw it off and make it need reprogramed?
Take it to a dealer (need to find a reputable mechanic in the northern virginia area, NOT POHANKA the rip off artist)?

Sort of at the end of my rope here, I appreciate everyone's help and or suggestions.

 

OK, here's a wild-***-guess for you:

I was diagnosing a similar problem in another car where after it
warmed up, going over a bump would cause the car to start
running badly and lose power to the point that you had to pull
over.

Turns out that a wire bundle running near the exhaust manifold
had melted the insulation of several wires together, but you
couldn't see it. It wasn't until you tried to see the separate
wires that you would notice they were welded together. Just
a couple of strands were close enough that if you moved the
wire around they would occasionally short out. This, of course,
was for a crank sensor.

Since you mention that you recently installed headers, this came
to mind.

 

I am afraid of that, thanks for the suggestion I'll have it up in the air again tonight (spends more time w/ the tires off than on). Thanks for the suggestion, I'll keep everyone posted.

 

Your getting the dreaded NO COMMS codes. Every module must communicate with each other to work properly. I cant tell if the wheel speed sensor or the NO COMMS issue is causing your problems.

There are a couple of places where the serial buss has had shorting problems in the past. One is in the LDCM and or RDCM. Remove the accordion tube between the doors and the body and examine the large connector. If you see any bare wires (insulation pulled back), that could be causing the issue with the no COMMS. It was causing me to have some real crazy problems. Almost got stranded 200 miles from home! I fixed that problem and she has been fine ever since


My speed sensor wiring failed at the connector on the passengers side. The connector that is mounted on the frame The one where the jumper harness plugs into) had bad female pins.

The other area of serial buss wire failure is the seat control modules. The plugs for the modules are close to the floor and get damaged. Look for damaged plugs, bare wires corrosion etc.

Yep, inspect the wires close to the header install.

Also, look for harnesses that could FLEX under high G loading. Tie them to something that will stabilize it and see if it changes your symptoms.

BC

 

Im home now and can post pics. Here is the door connector with a bad wire ( insulation pulled back) :





The black rubber tube just pops out and easily back in whan your done.

Take a close look at position K.

BC

 

It got late before I could check the harnesses in the door.

I couldn't find them. Pulled back the black rubber and felt as far into the door and down the rubber hose to where the backbone splits int two as its entering the passenger compartment. Its almost lik I would need to open the door or get access under the dash to find the harness. Any ideas?

It was the same on both sides.

I havn't given the rest of the car a look over for harnesses getting g loading yet. I took a lot of care to keep any wires away from the headers. I have retraced my steps and inspected the wires, but nothing like removing the headers to re inspect.

My car throws a hoast of codes and no comms. I believe a door mirror was referenced earlier. I will check the post and see which one. that might be the place to start. (i dont see a smiley face shrugging sooo... works )

 

With the hoast of codes, I think It might be a serial bus connection but I'm tired of thinking it might be this or that (sry for bitching). It may be one bad plug full of shorts throwing all sorts of codes. I've also fought with the steering column lock (had recall performed 4 times) and a continually fluctuating low battery voltage, lights flickering when I push on the brakes of other accesories. Fuel pump crapped out at 41k. The thing has been towed from the track 3 times, not because of a wreck but because of the column lock (2x), and fuel pump. Nothing like running well with the PCA and BMW cca, then have the POS towed b/c it broke sitting in the pits w/ no one around. How embarassing for corvettes, chevy , and me.

Any one want to buy a 97 Nassaw blue corvette? 43 k, sport seats, bose, runs strong!!

I will retracing my steps with the header install (ugh). remove the heads, carpet, inside of the doors, and just keep digging. The bummer is I won't be able to drive the car untill its back together to see if I got the short(s), but I guess its like a box of choclates, you never know what your gonna get in the center. I pray it will be obvious and hope this is from something I did and not from the factory.

 

Sorry for all the bitching, I will get to work this weekend on un installing the headers and look for things along the way.

I need to decide if I want to spend the time and money turning this car into a full fledged track/race car, or get a Z06 w/o all the problems I can track and drive on the street. I think I will end up spending the same amount of money either way.


Thanks again for the help I will let you know what I find