getting a b3971 code on my tech2 and top is stopping midway in the process,
always at the same spot, closing or opening, does anyone know which sensor this is?
all help is needed since I don't have any dealers to ask here in Sweden
Are you using a GM Service manual? What rev is your 32M card in your Tech 2? What year is your car? I can find DTCs only up to B3849 in my Service manual.
The first step: Have you made a list of the expected/actual readings of the Folding Top switches and sensors? Having that with the understanding of the order of how the folding top operates, and you can quickly what sensor/switch is causing the abort of the movement cycle.
Before you go any further, obtain a set of Service manuals. You can buy them from www.helminc.com
A Tech 2 is little more than a fancy toy without the GM service documentation. The screen you showed indicates a (DTC) fault, but you already knew you had a problem.
There are three things you need to troubleshoot the Folding Top, and you already have one of them. The next two (test setup and system knowledge) require the Service manual. The Service manual explains the testing and troubleshooting sequence, and lists what Tech 2 test tree screens are needed to obtain more test results. The Service manual has a section for each major component/system, that explains in great detail how it works and what sensors are used to detect a fault when it isn't. Are you starting to see a theme here? You need the Service manual to understand how the vehicle works. All the Tech 2 does is tell you what sensor readings were flagged. You have to know the exact sequence of the Folding Top operation to understand which sensor reading is requires for each step in the movement cycle to complete before the next can begin. The Service manual explains it.
With that being said, your basic scan won't tell you much --as you've learned. You need to look into the Folding Top system sensor readings, to understand what isn't working. That requires the Tech 2 peer into the Folding Top Control Module. All of the sensor inputs the Folding Top needs to function are reported to this module, and available to read and compare with a Tech 2. You need to navigate to the Body and Acc<Roof<Body and Acc<Folding Top Module<Inputs screen to read the system status. You want to write all of these values down and compare them whenever there's a problem. You'll find the faulty position sensor within thirty seconds. You can operate the folding top to watch the sensors update in real time and note which sensor is out of tolerance too. I keep a folded copy of my Folding Top values right on the page in the manual where the Folding Top Relearn procedure resides, and it's the first thing I check when there's any kind of malfunction. The second thing I check is the financial level indicator in my wallet.
thank you sir, appreciate it, I just bought myself a .pdf service manual and it seems to
cover all off the above, I have ordered a new top sensor, getting it on thursday, going
to install it and perform a relearn procedure and I will go from there, I will keep you
posted and again, really appreciate your efforts to help me
sometimes my trunk hesitates when putting my top up/down, it lifts a couple of
inches then slams closed and the "bong" sounds, then I push the button again and
it usully works, if not it takes a couple of tries, this also happens sometimes when
I want to open the trunk via remote or button, opens a couple of inches and then slams
closed, it ALWAYS works after a couple of tries. No trouble codes on tech2....I'm thinking
maybe another sensor is bad....any ideas?
You won't always see DTCs on the Tech 2 if a reported sensor value is on the hairy edge of it's Open or Closed Reference Value. This is why you should record all sensor values when the system works so you can quickly focus on components that might be bad when it doesn't. How do your sensors values compare to those from a week ago?
Other issues that might prevent the top from fully opening consistently are contaminated electrical connections in the Folding Top Control Module, (doubtful, it ought to throw a DTC) binding lift mechanisms, leaky solenoid operated valves, (there are six on the manifold) insufficient hydraulic fluid in the reservoir, or a hydraulic pump dying a slow death.
PS: There's no need to PM me, as I see the most current messages when they're posted.