badomen

Scary as all hell. Couple of days ago, my '01 Z06 started flashing Active Handling on the HUD every 5 minutes or so and, at higher speeds (over 60 mph) applying the brakes on the passengers side. Here's my details...

'01 Z06 no major mods (Ripper shifter, Borla, Blackwing - all 10+ years old). Stock tire size, lowered on stock bolts (also done years and years ago)

New battery as of 6 months ago. When this first happened, I thought it was possibly a low battery thing with the computer getting confused - especially since I hadn't driven it in a week or so. Dropped it onto a Battery Tender for a few days and took it out again. Still happens with a fully charged battery.

The only current code I've got is P0410 (AIR system) - and I've had it for about 5 months now. Been putting off replacing the valves. Again, the active handling issue is brand new so I'm thinking they're not related but maybe???

Here's what I have as far as codes showing up in history:

A0 - LDCM B2262 Horizontal Position Sensor Fit
A0 - LDCM B2264 Vertical Position Sensor Fault
A0 - LDCM U1064 Loss Of Communications With BCM

A1 - RDCM B2263 Horizontal Position Sensor Fit
A1 - RDCM B2265 Horizontal Position Sensor Fault
A1 - RDCM U1064 Loss Of Communications With BCM

If I shut off Active Handling, at least I can drive it without the crap engaging and trying to pull me off the road. That being said I'd really like to see if anyone knows what sensor is dying on me and how nasty it will be to replace it.... Be interested in hearing from anyone who's dealt with this before. Thanks much!! Al

coia96vette

Sounds like the SWPS is on its way out. It takes awhile to set codes. They will be C1287 and/or C1288. Same thing happened to my 04. Differently gets your attention when it happens at speed. Luckily they are still available for your 01 and cost about $65.

badomen

Awesome (well, kinda...). At least the answers are. Thanks guys - guess I'll grab a new SWPS and deal with it in the spring when Chicago thaws out. Not like I'll be driving it much in the winter anyway. Really appreciate!!!

dadaroo

Let us know if you need guidance on replacement. It is not a simple task but it is a DIY one.


Mr. Sam

badomen

Will do. Read through a couple guides on the forum. Doesn't look altogether terrible as long as I pull the airbag fuse and disconnect the column lock bypass. Seems to be far less of a PITA than I'm looking at to replace the two AIR valves. Lots of fun to look forward to in the spring...

Bill Curlee

Something that you need to do before you invest in NEW PARTS.

Clear ALL the DTCs. Monitor Frequently and see what reappears.

When you experience the Active Handling Issue, before you turn OFF the ignition, read and post all the DTCs. When you turn the ignition key OFF, the EBTCM clears most of the DTCS in its memory.

Each time you turn the key ON, the EBTCM runs a self test and it checks ALL of its micro processors functionality and all of the sub-sensors (WSS, Pressure Sensor SWPS, accelerometers, ect.. and communicates the PASS FAIL to the BCM. The BCM interfaces with the IPC and that's where you see all the messages and lights..

When it screws up, If there ISNT A DTC listed for the EBTCM,,,, the EBTCM "THINKS" it doing the correct thing. Some sensor is giving the EBTCM "FALSE" data. Its usually the SWPC but, it could also be a WSS or any sensor for that matter.

The ONLY way to know for sure is to put a GM TECH2 on the OBD2 Port and scan the EBTCM through the serial data buss. That will PIN POINT what EBTCM "SENSOR" is causing active handling to activate.

badomen

Thanks Bill. Needless to say, I don't have access to a Tech II scanner.... However, I will definitely get the car out in the next few days, run it until the message appears on the DIC and then read codes before shutting off the car. Good to know. Soon as I do, I'll report back. Cheers

badomen

Took her out today for about 15 minutes. Like usual Active Handling lit up after about 5 min and engaged the brakes - this time at low speed. Before shutting it off I pulled the codes - nothing different from before. Assuming at this point I'm kind of out of options without a Tech II, huh?

I agree with not wanting to buy unneeded parts so I'll probably dig up a GM mechanic before I deal with this in the spring and have him scan it to be sure.

Thanks again!

GUSTO14

Without a doubt, there is someone nearby that has, or knows someone that has, a Tech II. Check in the regional section and ask if someone in your area has one and is willing to run some diagnostics for you. There are 4 or 5 folks in my area (other than the dealerships) that have them and are willing to assist. Some do charge a small fee.

Good luck... GUSTO

wcsinx

My car was behaving similarly before it finally set a code for the SWPS. It would also disengage cruise every few minutes. I hate to tell you to be a blind part swapper when Bill has given you excellent advice on pinpointing the problem, but this is a pretty common problem with a very consistent set of symptoms which you are in fact displaying.

And be sure you disengage AH/TC everytime you drive until you get it fixed. That'll at least keep your car from acting up.

dadaroo

badomen

Thanks guys. Don't think much is gonna happen for a while given the weather that's about to roll through Chicago but really appreciate all the advice. Cheers

Bill Dearborn

One other thing you should check is whether or not your wheel alignment is causing the problem. If your steering wheel is off center by a certain amount that might cause the activation. Another thing to check is the lateral accelerometer sensor on the passenger side floorboard. If that has been disturbed that could be cause the problem. The yaw sensor in the center stack could also be a cause.

Bill

dadaroo

Damn Bill, that was good input on alignment. We should have thought about that since we knew it can cause that issue. That's why having more eyes on it is good.


Mr. Sam

Bill Curlee

TOTALLY AGREE!! Great recommendation!

badomen

Good to know. As far as the alignment goes, everything feels right going by the seat-of-pants test (for what that's worth...) and I can't recall any kind of pothole, etc that may have thrown it off before this started. Still agree it's worth my looking into.

Can I assume that when I hook up with someone who has a TechII scanner, any issues with the lateral accelerometer and/or yaw sensor would show up?

Thanks again to all of you guys - unbelievably helpful info all around!! Hope you have yourselves a great Thanksgiving!

Bill Curlee

The TECH 2 can examine each SUB SENSOR OUTPUT. If one of the sensors is providing an output, you can see it.

That goes for the SWPS output also.

1. It need to be at the NULL VOLTAGE, (from memory, I believe it something like 2.5 VDC when the steering wheel is dead nuts ZERO.
If you are not at NULL at ZERO steering angle, it could be an alignment issue.

2. The voltage out for the SWPS should be smooth and linier. The SWPS output has a Phase "A" voltage & Phase "B" Voltage EXAMPLE= If phase A is reading 4 VDC, Phase B should be reading 1 VDC. There opposite in value. Its a checks and balances thing for the EBTCM.

3. If one of the phases has NOISE (voltage spikes) in the output signal, it can cause issues.

badomen

So, wanted to check in with a (hopefully final) update. It was only $75 so I bought a new SWPS and figured what the hell - it's worth a shot. Girlfriend and I pulled the column and had the whole thing replaced and back together in a little over 3 hours. Been driving it off and on for a week and everything seems good. Still hesitant to take it onto a highway until I test it more but no messages on the DIC / no brakes grabbing at random times. Pretty happy.... Thanks again for all the info - you guys are awesome. Cheers!

nascar03

Hi Badomen..
Thanx for the update..
I'm glad that all worked out.
And kudos to you for tackling this retrofit.
When my SWPS acted up a couple of years ago I did all the reading and decided to let the dealer do this job. That air-bag thing scared me.
Great job.

Graham.