Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that there's a problem with the car's communication system, like when your phone can't connect to Wi-Fi because the wires are mixed up.
The FlexRay circuit is responsible for high-speed communication between various electronic components in the vehicle. A short circuit means that the electrical signals are not traveling correctly due to a wiring issue.
The C1104 code indicates a short circuit condition in the FlexRay communication network. This network is used for data exchange between multiple control units in the vehicle. A short in the FlexRay_High or FlexRay_Low circuit can disrupt communication, leading to various system malfunctions.
• Warning lights on the dashboard
• Intermittent loss of communication between control modules
• Erratic vehicle behavior
• Damaged or corroded wiring in the FlexRay circuit
• Faulty FlexRay control module
• Poor connections at the FlexRay connectors
FlexRay: A high-speed communication protocol used in automotive networks.
Short Circuit: An electrical fault where current travels along an unintended path.
• Inspect the FlexRay wiring for damage or corrosion
• Check the connections at the FlexRay connectors
• Use a diagnostic tool to test the FlexRay control module
• Repair or replace damaged wiring
• Clean and secure all FlexRay connectors
• Replace the FlexRay control module if faulty
• OBD-II scanner
• Multimeter
• Wiring repair kit
$200 - $600
Moderate
• BMW 3 Series
• Audi A4
• Mercedes-Benz C-Class
• Regular inspection of vehicle wiring
• Avoiding exposure of vehicle electronics to moisture
• Routine maintenance checks
Communication Network Issue
• Avoid driving the vehicle until the issue is diagnosed and repaired
• Consult a professional mechanic for accurate diagnosis
Check with the vehicle manufacturer for warranty coverage on electronic components.
The C1104 code has become more common with the increased use of high-speed communication networks in modern vehicles.
High – A short in the communication network can lead to serious vehicle malfunctions.
Driving with a faulty communication system can be dangerous and is not recommended.
• Vehicle at operating temperature
• All electronic systems powered on
The FlexRay network components are typically located throughout the vehicle, connecting various control modules.
Q: Can I drive with a C1104 code?
A: It's not recommended as it can lead to unpredictable vehicle behavior.
Q: How do I know if my FlexRay circuit is shorted?
A: A diagnostic scan tool can help identify a short circuit in the FlexRay network.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
View on Amazon
Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
View on Amazon
Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.