2014-2019 Freightliner Cascadia truck owners are very familiar with a certain module that causes major issues. This module is known as the CPC4. It’s a powerhouse of communication for the truck, but when it fails, it can completely disable the entire vehicle, leaving you stranded with no easy fix. CPC failure can be one of the most frustrating experiences to deal with on the road, so in this article, we’re going to walk you through what the CPC does, what the common symptoms are, and how to get your truck back up and running with minimal downtime.

What is a CPC4 and what does it do

The CPC4 (Common Powertrain Controller 4th Generation) is essentially the communication hub for the powertrain. It uses data from sensors like those on the throttle and brake to manage communication with other modules such as the MCM (Motor Control Module) and TCM (Transmission Control Module). It’s a “module manager” of sorts, acting as the main source of data for many of the other modules. Without the CPC, the entire powertrain will not function at all, so it’s a critical component for your truck.

Common Symptoms of a Failed CPC4

The most common issues that indicate a faulty CPC include:

• The truck not starting or starting intermittently
• The throttle being dead or intermittent
• The CPC reading as a different module (CPC2, TCM, etc.)
• CPC Hardware Failure Fault Code SPN 609 FMI 12

If you’re experiencing a communication failure, you may also have the following symptoms:

• Check Engine Light is on
• ABS Light staying on
• DEF Light staying on
• Instrument Cluster loses communication

What Causes a CPC4 to Go Bad

The CPC uses a chip with a package type known as “BGA” (Ball Grid Array). The connections to this chip can crack due to repeated thermal cycles and constant vibration from the truck. These disconnections lead to the variety of symptoms that point to CPC failure. Of course, due to the wide variety of nuances with electronic modules, there are often other failures that are either caused by the chip disconnecting or in addition to it.

How to Fix a CPC4

Finding a replacement CPC can be quite frustrating. OEM replacements have historically been difficult to source, and used modules are a gamble. In addition, both options are likely to leave you in the same position down the road as they have the same manufacturing defects that cause failure. You’ll also usually have to pay to have the module programmed to be compatible with your truck.

At Circuit Board Medics, we remanufacture CPCs to function better than new. We completely rebuild the modules to address all known failure points in a way that prevents you from having the same problem down the road. The modules are plug-n-play and come pre-programmed for your vehicle which will save you both time and money. We offer CPCs as an exchange, but if your truck has custom tuning, we offer a repair service that will preserve your programming. Both services are covered by our no-hassle 3-year warranty.

If you’re ready to get back on the road quickly, you can shop for repair and exchange services here. If you have any questions, you can give us a call or text at (800) 547-2049. We appreciate the opportunity to serve you!