U0061 means the voltage on CAN bus D has fallen below the normal level, indicating the bus is being pulled low or has an open circuit. This disrupts communication between all modules that share bus D, which can cause multiple systems to malfunction or go into a safe‑mode state.
Damaged, chafed, or corroded CAN‑H or CAN‑L wires in the bus D harness can pull the bus low or break continuity, triggering U0061.
A defective transceiver inside a module (e.g., ABS, BCM, or body controller) can continuously drive the bus low, causing the code.
Poor contact at a CAN bus D connector increases resistance or creates a short to ground, lowering bus voltage.
A malfunctioning control module on bus D (internal fault) may draw excessive current, dragging the bus voltage below spec.
If the voltage supplying the CAN transceivers on bus D is low, the bus may appear low even though the wires are intact.
Although rare, a faulty transceiver inside the powertrain control module can cause a low bus condition; this is considered only after all wiring and module checks.
No. The PCM/ECM is rarely at fault for a low CAN bus D condition. Most cases are due to wiring, connector, or transceiver issues in other modules on that bus. Replacing the PCM should be a last resort after those items are checked.
Yes. If the fuse supplying power to the CAN transceivers on bus D is open, the bus may read low voltage, triggering the code.
A basic multimeter can check continuity, resistance, and voltage. A CAN bus oscilloscope or scan tool with live data can help see bus activity, but many shops start with the multimeter and visual inspection.
Clearing U0061 only removes the stored code; if the underlying fault remains, the code will return shortly after the vehicle is driven or the bus is re‑powered.