Modern heavy vehicles have so many different moving parts, but they also have a lot of electronics that support these systems. Whether it’s the engine, transmission or braking systems, faults are generally diagnosed electronically. To properly identify vehicle issues, truck operators use diagnostic tools known as fault readers or fault clearers.
Truck electronic control units (ECUs) typically generate fault codes when something is performing suboptimally. Rather than performing a lot of hands-on investigation, operators can read these fault codes to give them vital information about truck issues.
OBD stands for on-board diagnostics, a series of fault codes relating to different aspects of a vehicle’s operation. The early diagnostic systems were very basic, providing truck operators with a malfunction indicator if something was wrong. The problem was, the codes on every manufacturer’s trucks were different making it problematic for operators to understand which issues were present.
As a result, OBD II codes were developed in 1996. This standardised format ensured that all truck diagnostics emit the same fault codes when something goes wrong. Not only does this make things easy for operators, but it has also allowed for universal fault readers to be developed. The codes provided are referred to as Diagnostic Trouble Codes (DTC).
A DTC code features a 5-digit display, with all codes keeping this uniform layout to make it easy for operators. The first digit is actually a letter, reflecting where the issues have been found.
P – Powertrain
B – Body
C – Chassis
U – Network
The second digit will be either 0 or 1, with 0 indicating a generic fault and 1 showing a manufacturer-specific problem. Finally, the last 3 digits show the specific vehicle circuit and system where the error has been located.
Once the operator has established where the issue is and, more importantly, what the issue is, they can take appropriate action. They can quickly determine which aftermarket truck parts they may need, and how long they will take to repair.
The latest-generation Bosch Handheld Scantool is a terrific diagnostic device that accesses OBD II codes and meets all SAE standards for heavy-duty communication (CAN) systems. The great thing is that you can connect the device online to update new vehicles and information.
The Bosch Scantool can check for faults and errors in the engine, transmission and braking systems and works on either 12V or 24V power. While you would normally use larger diagnostic tools in a static environment like a workshop, the Bosch is a brilliant portable solution. For field repairs where you might need to read and clear standard fault codes, this offers great flexibility and ease of use.
Jaltest is a well-known name in the field of connectivity and diagnostics for heavy vehicles. Their portable fault reader, the Jaltest PTE offers exceptional usability for truck and trailer system testing. The PTE has a hard carry case, ensuring it won’t be damaged easily when not in use, and is designed for one operator to use competently without assistance.
With the Jaltest PTE, users can check electrical signals, lighting devices and communication lines. It is self-powered, using simple ISO connectors to check trailer light function, even when the truck itself is not connected.