A vehicle’s communication network relies on Controller Area Network (CAN) lines, primarily CAN A and CAN B, to facilitate data exchange between various modules. Code U0019 indicates a problem with this communication, often manifesting as intermittent issues. This article explores potential causes and troubleshooting steps for code U0019, particularly focusing on scenarios involving vehicle conversions.
One possible cause of an intermittent U0019 code, coupled with low battery voltage, is a short to ground in the CAN line. This can occur when a wire within the CAN network makes unintended contact with the vehicle’s chassis. Unlike more severe faults, which often trigger a flashing odometer, intermittent communication issues can be challenging to diagnose.
Vehicle conversions, such as transforming a van into a motorhome, increase the risk of disrupting CAN lines. During the conversion process, wires can be trapped, pulled loose, or damaged. The location of the fault depends on the nature of the conversion. If the conversion primarily involved the living area, the problem might lie in the wiring loom under the vehicle where water or waste tanks might have been installed. Work in the engine bay, like adding electrical components, also presents opportunities for CAN line damage.
Aftermarket radio installations are another common culprit for U0019. Fiat, for instance, utilizes two connections within the standard ISO connector for CAN lines. Failing to use a proper wiring adapter can lead to communication errors. Therefore, verifying the correct installation of any aftermarket components, especially those interacting with the vehicle’s electrical system, is crucial.
Pinpointing the exact location of the fault often requires meticulous inspection of the wiring harness. Looking for signs of damage, such as pinched wires, loose connections, or exposed conductors, is key. If the conversion involved areas where wiring might be vulnerable, like under the vehicle or near newly installed components, focusing on those areas first can expedite the diagnostic process.
