This is how to fix intermittent ABS and Brake dash lights on all Chevrolet vehicles with the Kelsey-Hayes 325 EBCM module. You may have code C0265 "Electronic Brake Control Module Motor Relay Circuit." The fault is usually due to corrupted solder joints on the circuit board to which the motor relay circuit is connected and is easily repaired with additional solder. The warning lights are intermittent whereas the poor solder joints result in brief communication interruptions with the relay circuit. The warnings will extinguish when reset (turning the vehicle off/on) and will illuminate again once the circuit loses its communications path. *To address comments/concerns: 1. The Torx sizes I indicated are correct for MY vehicle. Assembly locations, dates of manufacture, vehicle models, etc. resulted in the use of different Torx sizes by the manufacturer. Please direct all complaints to Kelsey-Hayes because I don't care that your Astro van didn't match the specs of my Tahoe. Seriously? 2. Thermal Paste: The following information is supported by the people who designed these units so you may want to read it before commenting. In the video I use 100% silicone inside the module in place of thermal paste and allowed time for the silicone to cure prior to reassembly (to prevent adhesion). The manufacturer applied thermal paste to isolated locations on the circuit board (an insulator), so it had no thermal benefit. The circuit board is constructed of fiberglass embedded within epoxy resin and does not transfer heat to the case, even if you connect them with conductive paste. An oven mitt is better than fiberglass at transferring heat. If the circuit board was not an insulator, there would be a cluster f*ck of electrons rather than directed flow between components via printed copper routing. Understand that thermal paste fills in microscopic gaps to aide in heat transfer between HEAT CONDUCTIVE materials such as those found on CPUs and heatsinks. For those that argue the necessity of thermal paste: How are you transferring component heat to the metal cover with thermal paste stuck to a fiberglass insulator? Physics are certainly not your friend. Since the "thermal paste" has no thermal benefit when placed on epoxy resin fiberglass, I logically concluded that it was being used as an isolator. (Remember, you are most likely watching this video because of GM's failure to properly isolate that control module from movement/impacts via bolting it directly to the frame.) Further, the module sits fairly close to extremely hot pavement on which eggs can be fried. If heat transference was occurring with outside temperatures exceeding internal conditions, you'd be transferring higher temperatures into the module. (Following mountain driving with a 4500lb boat, the module wasn't even warm with outside temperatures of 60 degrees. My phone operates at a higher temperature than the control module.) If you redesigned the module to dissipate component heat to the case, you'll merely succeed in transferring that 150 degree summer asphalt heat right to the components (which were happy operating at a much lower temperature prior to your act of genius. Some modules are even installed in a hot engine compartment) Physics does not support the many comments declaring fiberglass to be a conductor of heat requiring thermal paste. I contacted Kelsey-Hayes and they agree that the paste they used has no thermal significance when applied to fiberglass. It was agreed that it may have been used as an isolator and that concerns of adhesion with a circuit board would have resulted in the decision to use thermal paste. I did let the silicone set prior to installing the cover in order to prevent adhesion, but in the manufacturing process such delays would not be feasible. There's no concern of corrosion whereas it was only applied to the epoxy resin fiberglass board in the areas that have no electrical components/connections.

• published: 22 Dec 2012
• views: 500347