U0014 MS-CAN High Voltage Fault
The U0014 code indicates that the engine control module (ECU) has detected a high voltage condition or fault on the CAN High line of the medium-speed CAN (MS-CAN) bus. This bus handles communication between body control modules such as the BCM, door panels, climate control, and instrument cluster. The fault prevents reliable data transmission on that specific line.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Open circuit or short to voltage on the MS-CAN High (MS-CAN+) line
- Damaged or missing bus termination resistor
- Faulty control module pulling the line high
- Corroded, loose, or damaged pins/connectors in the medium-speed bus
- Wiring chafed or cut in the MS-CAN harness
3. Symptoms You Will Notice
- Malfunctioning body electronics (windows, locks, climate control)
- Instrument cluster warning lights or erratic gauge behavior
4. Step-by-Step Diagnosis
Scan for all stored codes and note related modules
Inspect MS-CAN wiring and connectors for damage or corrosion
Measure resistance between CAN High and CAN Low at the OBD2 port (should be ~60 ohms)
Check for voltage on CAN High line (should be ~2.5V with ignition on)
Isolate modules by disconnecting them one at a time to find the fault
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, but you may experience intermittent or non-functional body electronics. It's best to diagnose and repair promptly to avoid further issues.
How much does it cost to fix?▼
Typically $100-$400 depending on the cause (wiring repair vs. module replacement).