A couple of decades ago, all of our vehicle systems were manual and had to be checked manually, from tire pressure to exhaust emissions. As technology has evolved, our cars have also evolved and now carry a small computer that manages and controls many of the functions of your vehicle. The CPC4 module is the name of the computer found in Freightliner trucks. It is responsible for the coordination and control of the many systems within your truck. The one disadvantage that these clever computers have, is that if the computer fails or becomes damaged, multiple aspects of the vehicle become affected.
7 COMMON PCM FAILURE SYMPTOMS:
YOUR “CHECK ENGINE” LIGHT IS ON
If your check engine light comes on, it indicates that something is wrong, however, this can be due to several different things so it is important to get your CPC4 module checked by a professional.
YOUR CAR WON’T START
If your truck takes several attempts to get started or will not start at all, this is a common sign that there is a problem with your Freightliner CPC4. There are several possibilities that can cause this to occur, including incorrect engine timing, a shortage in the wiring harness, or an improperly balanced fuel-to-air ratio. So it is important to get a professional to check your CPC4 and your truck.
SUDDEN LOSS OF GAS MILEAGE
One function of your CPC4 module is the control of your fuel-to-air ratio and when to shift gears. If these are not working correctly your gas mileage will be affected.
YOU FAILED YOUR EMISSIONS TEST
If you need Freightliner CPC repair it may affect your fuel-to-air ratio. If there is too much fuel compared to air, you will be giving out more harmful emissions as the fuel won't fully combust.
YOUR ENGINE STUTTERS OR STALLS
If you are experiencing stuttering or stalling this is a sure sign that either you have a serious engine problem or that your CPC4 is failing. This is typically caused by a problem with the engine timing, although there are several reasons that can lead to this problem.
ERRATIC OR RANDOM SHIFTING
Irregular shifting is one of the more serious CPC4 Freightliner problems. It occurs due to a faulty sensor or because of water damage in the circuits of your CPC4. Your truck could get stuck in gear which is a serious safety problem and expensive transmission damage can occur.
YOU’RE RECEIVING A CPC4-RELATED ERROR CODE
If your CPC4 module detects a problem or has a problem itself, it will log an error code informing you of the problem. These codes can be read by code reader devices.