Gentlemen,
Aftermarket scan gauges yes are nice for some things but way too much faith is used in determining problems. The amount of information is provided from a Caterpillar program systems called Messenger. Yes there is a message of problem and gives out a fault code, this is great but what it does not do is break out the fault code to understand what is happening. Each fault code if active or just an event happening has several areas; is the problem is a replacement of part, dirty or loose connection, high voltage count or low voltage.
Many fault codes are caused by a mechanical problem and chase problem to different areas that one would think replacement of part that is electrical problem. I run into this misunderstanding many times troubleshooting problems using a Caterpillar service tool called Cat ET. Your code reader or scan gauge kinda lets you know the problem is present and that’s about it. In closing, your caterpillar engine has fail safe systems in place to prevent problems via power reductions or engine derate . Good examples are event code 173-0 High Exhaust Temperature or event code 173-11 Extreme Exhaust Temperature, Both of these event codes break down to be operating by lugging engine below 1400 rpms with caterpillar 3126 A model through caterpillar C-9 with the HEUI injection system.
Dave Atherton Retired Cat Mechanic