U0015 MS-CAN Bus Open Circuit
The U0015 code indicates that a control module has detected an open circuit condition on the Medium Speed CAN (MS-CAN) bus. This means there is a physical break in the CAN High or CAN Low wiring, or a missing or faulty termination resistor, preventing communication between modules on this bus (typically body, HVAC, instrument cluster, etc.).
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 in CAN High (Bus +) or CAN Low (Bus -) wiring of the MS-CAN bus
- Damaged, missing, or out-of-spec (120 ohm) termination resistor on the bus
- Loose, corroded, or damaged terminals in a control module connector
- Internal failure of the CAN transceiver in one of the modules connected to the bus
- Short to battery or ground on a bus line that forces the driver to shut down
3. Symptoms You Will Notice
- Malfunction indicator lamp (MIL) illuminated
- Inoperative or erratic operation of body, HVAC, or instrument cluster functions
4. Step-by-Step Diagnosis
Scan all modules for related communication codes and note which modules are offline
Check MS-CAN bus wiring for opens, shorts, or damage using a multimeter or oscilloscope
Measure resistance between CAN High and CAN Low at the bus; should be approximately 60 ohms (two 120 ohm termination resistors in parallel)
Inspect all module connectors on the MS-CAN bus for corrosion, bent pins, or poor contact
If resistance is 120 ohms, one termination resistor is missing; if open, both are missing or there is a wiring break
5. Frequently Asked Questions
Is it safe to drive?▼
The vehicle may still be drivable, but some body, HVAC, or instrument cluster functions may not work properly. It is recommended to diagnose and repair the issue soon to avoid further communication problems.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the issue is a simple wiring repair, a faulty termination resistor, or a module replacement.