RP 146 - Identification Of Standardized Electrical Circuits For Class 8 Vehicles: Background

Due to electrical and electronic engineering advances, there have been significant increases in the content of vehicle power and distribution systems. Though this increase of features and devices has contributed to commercial vehicle performance, the associated increase of circuits has prompted increased complexity for service technicians. Efforts through TMC and SAE to improve this situation have resulted in the creation of SAE J2191, a document which:

• provides a common method of identifying circuit function for commercially available Class 8 vehicles,
• assists in the process of cross-referencing the circuits of the wiring assembly to the service manual or other general service documentation.
• provides an organized method of circuit identification to minimize vehicle downtime by enhancing the diagnostic capabilities of the service technician.

TMC endorses industry adoption of SAE J2191 as a means of simplifying vehicle serviceability and technician training.