I've been dealing with AH problems for a while now. I found the following thread informative http://forums.corvetteforum.com/show...ight=dtc+c1287

and I'm hoping perhaps BlackZ06 might be able to help. I've been getting C1286 and C1287 codes for a few weeks now, I have a 2000 Hard Top Coupe. On my daily commute I drive about 1/2 mile most days and it sets the 1287 code and later on during the trip it sets the 1286 code. I've been checking the DTC while driving to get a better handle on what happens when. Here is the weird thing, on some days I can drive about 20 miles and when I get off the highway and make a stop at the stop sign followed by a right turn then the C1287 code sets. It is always at the same point in the commute. If I get the 20 miles going home then the code sets in the same place under similar circumstances, in that case making a left turn. I am assuming it is the turn itself that triggers it. If I start my day with a short trip and set the code, stop at a store say 5 minutes or so then I get a DTC message saying active handling warming up. A few minutes later it says warm up complete and then the usual service active handling, etc messages and the C1287 code sets.

I guess I'm going to have to replace the steering wheel position sensor, a job I'm not looking forward to. What exactly is "Active Handling Warming up" all about. Could the EBCM be involved here?

What am I in for when I replace this sensor? The service manual procedure doesn't look too complicated. Is this something best left to the Stealership? By the way the car has never been in for an alignment, still tracks straight. With winter coming on I would like to fix this. It's a daily driver and yes I do drive it in the winter here in New York.

Thanks in advance for your help.

Mike

 

The Steering wheel Sensor Bias Malfunction is the c1286,It looks like u may have to replace a sterring wheel Sensor ,Have u replaced The yaw Rate Sensor ?If u havent i would start there The 1287 code is the Steering wheel sensor malfunction without RP0 JL4 The ebcm could be a problem yes ,bUt i wouldnt rule out sensors ,i would Deffinatley change the sensor before i replaced the module ,I just replaced wss Sensors & Module on my car its an 00 also

 

Let's start with the "easy" question ....

The "Active Handling Warming Up" message displays to warn you that Active Handling (AH) is not yet active on the vehicle. The reason it is not active is the EBCM has not been able to "calibrate" the SWPS because the following has not occured ...

* Vehicle speed over 6 MPH for more than 10 seconds

* Yaw and accelerometer are reporting ZERO (vehicle is going straight down a level road) during that 10 seconds.

Once those conditions are met the EBCM "calibrates" the SWPS output as "straight ahead". Once it has "calibrated" you will get the "AH Warm Up Complete" message on the DIC. Any change in the voltages from the two sides of the SWPS after that are interpreted as the steering wheel being turned.

-------------------------------

Now to your two codes .... basically the C1286 says the EBCM realizes that its calibration of the SWPS is no longer valid .... for example the yaw rate and lateral accelerometer are reporting ZERO, but the SWPS "says" the steering wheel is turned 90 degrees to the right ... and the wheel speed sensors say the car is travelling 60 MPH ... the EBCM figures somethings probably wrong with the SWPS.

The C1287 says the SWPS is reporting you are turning the steering wheel at more than 1100 degrees in a second (that's more than 3 complete turns of the steering wheel in less than a second) and/or the two sides of the SWPS are reporting steering angles that disagee by more than 20 degrees.

Bottom line, to me, sounds like a pretty clear case that the SWPS is getting flaky and should be replaced.

So, finally, you ask how big a pain this is to do yourself. Mechanically, as you can see in the manual, it isn't that difficult. You basically disconnect the steering shaft in the engine compartment, disconnect the column mounts under the dash, and then PARTIALLY remove the column, giving you enough room to remove the sensor and replace it without taking the whole assembly from the car.

Caveats .... Once you have disconnected the steering shaft DO NOT LET THE STEERING WHEEL/SHAFT ROTATE in the column. A few degrees is OK, but you basically want to prevent the wheel turning as it can snap the "clock spring" power source for the airbag.

Be sure to disconnect the battery before starting and wait (in my opinion) 5 minutes after disconnecting the battery before messing with ANY of the wiring on the column. The airbag system retains power for up to about 30 seconds (so it can fire even if the battery is disconnected in a crash) after the battery is disconnected. The airbags scare the crap out of me, so I am VERY cautious doing anything near them.

There is a pin in the new SWPS ... do NOT remove the pin until AFTER you have re-assembled everything and the steering shaft/wheel is in a straight position.

Only other issue is it is somewhat cramped working under the dash. I think I'm gonna remove my drivers seat (just some wiring and 4 bolts mounting the track to the body) the next time I do this. At my age playing contortionist is getting to be a pain in several parts of my body ....

Hope this helps ......

 

Thanks guys for the replies. If the Yaw sensor or Accelerometer were faulty I would expect them to set a code and they are not. I will go for the sensor, now I need to locate one at a reasonable price. The Stealership wants over $300 for one. Any suggestions?

The Airbags scare me too so I plan to be as careful as I can be around them. I was also thinking of removing the seat for all the same reasons you eluded to. What is unclear to me is just how much of the interior I have to disassemble to do this. If I believe the manual then I have a lot of things to remove or am I missing something here? Do I really have to remove the center console to do this or will the knee panel come off by itself? If so what is the best way to remove it. I see two press in plastic retainers on the lower panel and some thing way in the back I can't make out. I see 2 screws and nothing else obvious on the knee panel.

What if I removed the column lock bypass and let the column lock to keep the wheel from turning?

Half of my clutch return spring broke away so I may as well replace that too while I'm under there.

I am also having problems with the VAT system but that is a topic for another post, one problem at a time.

Mike

 

The sensor should be GM part # 26058286

try the supporting parts houses such as:

http://www.gmpartshouse.com/

http://www.gmpartsdirect.com/

They should carry the sensor for about half that price.

I'll post later answers to you other questions ... gotta run now.

 

I just had my replaced by the dealer, and total price, including labor was $340.

 

May not be the same, Mine would say Active handling warming up and it would take a good 20 to 30 miles to warms up. It turned out to be that one of the wires on the airtemp sensor was broke inside the insulation. Mine had nothing to do with turning. Also my idle was being stupid. It is easy to check. Good luck

 

See my post above for the part number and places to get it.

Think of the dash panels as "layered" .... the knee bolster was installed first and some of its mounting hardware is hidden behind the Trim panel (radio surround), which after install had its mounting hardware hidden by the center console, where its final hardware is hidden inside the flip top console. In other words, you do have to take the panels apart in the order specified. While it sounds difficult, the trick is to label screws and nuts as you take them out. I have a shoe box with a bunch of empty ziploc baggies and a notepad and pen. As I take out a set of screws or nuts I put them in a bag with a note where they came from. The first bag goes to the back of the box, the next bag in front of it, etc. When it is time to reinstall the bags SHOULD be in the correct order to put everything back together. At the end of the project I throw away the labels, put the baggies back in the box with notepad and pen, and use it again for my next project.

While it sounds daunting, it really isn't that hard. Just take your time and take stuff apart GENTLY in case you missed a fastener. There are a couple of times you will have to yank, but you'll know when those are. I always figure, worst case, I break something, order the part, pay the money, and learn a lesson ...


That should work fine ... so disconnect the steering column in the engine compartment, lock the column, and THEN disconnect the battery.

Absolutely .....

Depends, you're gonna have most of the VATS system exposed at this point, it might be worth attacking that too ......

 

Hey thanks again. On the subject of VATS in my 1988 I bought one of those bypass units because it became a constant headache. It's beginning again in the 2000. I made up a resistor chain to substitute for my key but that key switch looks like it is going to make it difficult to accomplish. There doesn't appear to be some intermediate connector like the '88 had. I have all sorts of weather-pac connectors and pins and was hoping to swap the resistor string for the wires from the switch. I don't want to cut and splice anything if I don't have to. Do you know what type of pins are used in there? Is it the metri-pac type?

By the way, will it be OK if I bypass it? The '88 didn't have all these sophisticated modules all talking to each other. I am kind of worried that with the BCM seeing a "Key" in the ignition when I park and leave will keep it from entering the standby mode.

Mike

 

See the following thread .... Post #2 tells you exactly how to do it .....

http://forums.corvetteforum.com/show...highlight=VATS

 

Wow BlackZ06 do you live in this forum? I was going to do some more research tonight and this is a good starting point. If that picture is correct then I can probably make it happen without too much bother. Thanks again.