If your 6.5L diesel (w/ the DS4 electronic injection pump) is showing symptoms of stalling, hard starting, and hesitation, you may not need to replace the injection pump just yet!
GM Technical Service Bulletin #77-63-06Ab states that: "stalling, hard starting, and hesitation are symptoms of a failing PMD (Pump Mounted Driver) module." These symptoms usually (but not always) set a code 35 or 36 in the 1994 - 1995 models, or a code 1216 in the 1996 - up models. Often when this problem is diagnosed at a dealership or repair shop, the customer is told that the injection pump needs to be replaced. But in most cases, the PMD module can simply be replaced for a fraction of the price.
The
PMD module, (also referred to as the "Fuel Solonoid Driver") has been a major
problem for Chevy / GMC 6.5L diesel owners since the introduction of the 6.5L
electronically controlled DS4 fuel injection pump. It has been determined that
heat is the primary cause of PMD failures. The PMD is mounted to the side of
the fuel injection pump from the factory. But the injection pump does not provide
adequate cooling to keep the PMD functional. Once the engine begins showing
symptoms of hesitating, stalling and hard starting, the problem will only worsen
with time. The problem only becomes more serious when considering the potential
danger of your engine stalling in a situation such as pulling into heavy traffic
or descending a steep hill and losing the use of power brakes and steering.
Tests show that when using the PMD Relocation Kits part #'s PMD-2 and PMD-4 , PMD temperatures will drop anywhere from 32° to 81° F* depending on driving conditions. These temperature drops will seriously increase the life of the PMD and can save you money from towing and costly repairs. The PMD Relocation Kit easily mounts on top of the skid plate to eliminate heat issues. Installation is quick, simple and does not require any modifications or special tools. The PMD Relocation Kit comes with everything needed, PMD, wire harness and skid plate mount.
If you already have a remote mount kit this PMD unit will not work - please call our Parts Department at 1-800-823-4444 for PMD units that have already been remotely mounted.
