Gerald Farris, you are the knowledgeable person that can help me. Long story begins with us traveling thru the mountains somewhere in the past 3 months. 2005 Monterey 400hp Cat C9. I used the exhaust brake on some steep long downgrades. (step on brake to disengage cruise control, then flip the switch, apply brake as needed to control speed). After some repeats of this, I had a yellow check engine light flashing. Oil pressure good, engine and transmission heat gauge good. I switched off the cruise control and the light stopped flashing. Sometime later on level terrain, I tried the cruise again and everything was good.
Today, we left South Tahoe headed to Reno. Same scenario, altho this time when I turned off the cruise it did not make a difference.
The check engine light would flash several times then go out, finally stayed off and we made our scheduled stop. I followed the instructions in my Cat owners manual and pulled error codes. error code 25, 16, 16, 57. We never lost power, all seemed normal.
The error code 25 says "An Inlet Air Pressure Sensor Circuit Fault". I could not find an explanation for error code 16. BTW, I had my navigator double check me and 3 times we had the same results. I read thru the BAC forum and did multiple searches for an answer. No banana! My owners CAT Manual does not show An Inlet Air Pressure Sensor, but shows an inlet air temp sensor and an "Atmospheric Pressure Sensor", so I have no idea what sensor is being called out as problematic. Finally to wrap this up, both times this has happened to me, has been after extended use of the exhaust brake. How do I check the operation of the exhaust brake? Is this a maintenance item? What's next Gerald? And Thanks!