What is Class 2 in GM vehicles that everyone is hearing about lately?
Class 2 or Class B is really a in-vehicle network SAE J1850 protocol that GM has been using for many years. It just a new data protocol that a majority of vehicle computer modules uses, which share the same single data wire through out the vehicle.
Recently GM has now included the driver’s door module, passenger’s door module, rear seat audio controller, vehicle communication interface module or OnStar®, steering wheel audio controls, rear seat entertainment (RSE), CD changer, radio, DVD/Video, amplifier and XM radio as part of Class 2. Since these new modules are part of the audio system and security system, you are now hearing more about Class 2.
Connected to this same data wire is the Body Control Module (BCM), Powertrain Control Module (PCM), Transfer Case Shift Control Module, Heater & A/C controls (HVAC), Inflatable Restraint Sensing and Diagnostic Module, Theft Deterrent Control Module, Memory Seat Module, Drivers Information Center (DIC), Key/Lights/Seatbelt Chimes (most vehicles), Instrument Panel Cluster (IPC), Suspension Control Module, Electronic Brake Control Module (EBCM) and other modules.
Someone on an earlier post mentioned a MP3 player being able to hook it up. I asked for more info but hadn't gotten yet. Also reading my manual while setting at Sonic. The AVOL is either off or on and has an inner autopilot system that makes it work. I did notice while sitting there playing with it that when I switched from on to off the volume changed. I think
it is so subtle that we can't tell it is working. Also the CD/Aux button is just that, in my Tahoe it says Aux instead of CD. The manual says push the CD/aux button when listening to the radio to hear the cd's.
I'm looking at 2 trucks and both owners have or are having an issue with fuel gauge malfunction. Both have blamed a Fuel Sender/sensor on the culprit. Is this a big deal repair. Some time the gauge I'm told doesn't read when full or near empty. My 05 never had an issue. Was I just lucky. How...
2003. This is what it does after startup.
1) If the mode knob is in any position but MAX DEFROST (all the way to the right), the system is dead. Moving TEMP or FAN knob has no effect.
2) Put mode knob to MAX DEFROST, system runs (Only MODE that this happens). FAN & TEMP operates as it should...
I had a problem with a 2005 6speed SSR with 24,000 miles on it. I just replaced the battery and ground cable about a week ago ( battery was 6 yrs old and not holding a charge ) and I had previously replaced the ignition switch to the newer style about 4 months ago and all has been well until...