CAN Communication Bus Fault? Now that’s generic. It is simply not enough to just know that the bus is running a fault code; you have to know exactly what part of the system is causing the issue. This is what our SureTrack technician had to find out when his customer’s 2006 Ford Cab & Chassis F350 Super Duty 5.4 rolled onto his bay.

Diagnosis

The technician scanned the car, which read code U1900 CAN Communication Bus Fault, meaning there was no communication with the anti-lock brake traction control module. The technician performed a visual inspection on the ABS, its traction control module, wiring harnesses and speed sensors. No obvious faults. He disconnected the anti-lock brake traction control module connectors and inspected the connectors and terminals, all of which looked good — no signs of loose pins, corrosion or damage.

He used a multi-meter to check for the presence of shorts or opens in the anti-lock brake traction control module wire circuits and found that none were present. Finally after checking for the presence of power and ground at the anti-lock brake traction control module harness connector with the multi-meter, he found both were present,  verifying the anti-lock brake traction control module was indeed faulty.

Fix

The technician ended up replacing the anti-lock brake traction control module, cleared the codes and performed a road test to verify that the vehicle operated correctly. Now the check engine light is off, no fault codes appear and this truck is home free and ready to go back to a satisfied customer.

SureTrack adds to the power of ProDemand from Mitchell 1 with an exclusive combination of expert knowledge and detailed parts replacement records, all wrapped in an interactive community. Read the Real Fix in the Mitchell 1 ShopConnection Blog.