U0004 FORD Possible Causes
- Diagnosis of this diagnostic trouble code (DTC) is performed via vehicle symptoms
- Check for more codes
- Faulty control module
- Control module harness is open or shorted
- Poor electrical connection in control module circuit
How is FORD U0004 Code Repaired?
Begin by checking the “Possible Causes” listed above. Visually inspect the wiring harness and associated connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
Check engine light illuminated (or service engine soon warning light)
U0004 FORD Meaning
Multiplexing is a method of simultaneously sending 2 or more signals over the same circuit. Multiplexing allows 2 or more electronic modules (nodes) to communicate over a twisted pair network [data (+) and data (-)]. The information or messages that can be communicated over these wires consist of commands, status, or data. Multiplexing reduces vehicle weight by decreasing the number of redundant components and electrical wiring. The vehicle has 4 module communication networks connected to the DLC, located under the dashboard. The communication networks are: High Speed Controller Area Network HEV (HS-CAN), High Speed Controller Area Network (HS-CAN), Medium Speed Controller Area Network (MS-CAN), and Infotainment Controller Area Network (I-CAN). Diagnostic trouble code (DTC) U0004 is set when a failure in the High Speed Controller Area Network (HS-CAN) was present at some point. The fault is not present because the module communicates with the scan tool