U041681 – Invalid data received from electronic stability system

What BYD DTC U041681 Actually Means

BYD U041681 is a manufacturer-specific network communication fault. The base code U0416 is defined under the SAE/ISO framework as “Invalid Data Received From Vehicle Dynamics Control Module” — and BYD’s 81 sub-type suffix narrows this to their Electronic Stability Control (ESC) system specifically. The code does not mean the ESC module has failed outright. It means one or more modules on the CAN bus attempted to read data from the ESC module and received a message that was invalid, corrupted, or outside expected parameters.This is a network-layer fault. The problem could be in the ESC module itself, in the wiring that carries CAN signals to and from it, in the module’s power or ground supply, or in a broader CAN bus disturbance affecting multiple nodes. Treating it as a simple ESC module replacement from the outset is one of the most common and expensive mistakes made with this code.

How BYD’s CAN Network Relates to This Code

BYD vehicles — including the Atto 3, Han, Tang, Seal, and Dolphin — use a multi-bus CAN architecture where the ESC module is a critical node. It continuously broadcasts wheel speed data, yaw rate, lateral acceleration, and stability intervention status to other modules including the powertrain control unit, the advanced driver assistance system (ADAS) module, and the instrument cluster. When any of these receiving modules detect that the ESC’s broadcast data is invalid — wrong checksum, message counter error, out-of-range signal values, or message timeout — U041681 is logged against the receiving module, and the fault may appear across several modules simultaneously.This is an important diagnostic distinction: the code is stored by the module that detected the problem, not necessarily by the ESC module itself. Always perform a full system scan before assuming anything.

Symptoms You May Notice With U041681

Depending on how severely the communication is disrupted, symptoms range from nearly invisible to quite noticeable:

• ESC / stability warning light illuminated on the dashboard
• ABS warning light on, often appearing alongside the ESC warning
• Traction control warning or traction control disabled message
• ADAS features (lane keep assist, automatic emergency braking) reduced or disabled — these depend on valid ESC data
• Speedometer or odometer reading behaving erratically in rare cases, if wheel speed data is compromised
• On BYD EVs and PHEVs, regenerative braking behaviour may be altered or limited
• No driveability symptoms at all in mild cases — the fault is often discovered only during a routine scan

The vehicle will typically continue to drive, but safety systems that rely on ESC data are compromised. This matters most in emergency situations.

Most Likely Causes — In Diagnostic Order

Work through these from the most common and least invasive first:

Priority	Cause	Notes
1	Damaged or corroded CAN bus wiring to the ESC module	Most common root cause on BYD models with higher mileage or after underbody work
2	Poor connector contact at the ESC module	Corrosion, bent pins, or a partially unseated connector
3	Loss of power or ground to the ESC module	A module that drops offline produces exactly this symptom in other modules
4	Software or calibration mismatch on the ESC module	Relevant after module replacement or incomplete software updates
5	Internal ESC module fault	Hardware failure — confirm only after ruling out all external causes
6	CAN bus termination resistance fault	A shorted or open CAN line affects all nodes — expect multiple U-codes if this is the cause

How to Diagnose U041681 on a BYD

Step 1 — Full System Scan First

Connect a BYD-compatible scanner capable of reading manufacturer-specific codes across all modules — not just the OBD2 port’s generic PIDs. Note every module that has stored U041681 or any other U04xx fault. The pattern of which modules are reporting faults tells you whether this is isolated to the ESC node or a broader network problem.

Step 2 — Visual Inspection of the ESC Module and Wiring

Locate the ESC module — on most BYD models it is mounted in the engine bay or near the brake hydraulic unit. Inspect the wiring harness for damage: chafing against body panels, heat damage, rodent damage, or stress from previous repairs. Unplug the ESC module connector and inspect both the connector body and the pins. Look for corrosion, green oxidation, pushed-back pins, or moisture inside the connector. Reseat the connector firmly.

Step 3 — Check ESC Module Power and Ground

With the ignition on, verify that the ESC module is receiving correct supply voltage and has solid ground continuity at its connector. A module with a marginal power or ground connection will drop off the CAN network intermittently, producing exactly this fault. Resistance to ground at the ground pin should be very close to zero ohms. Elevated resistance — even a few ohms — is enough to cause module communication failures. Refer to your vehicle-specific wiring diagram for exact pin locations, as these vary by BYD model and year.

Step 4 — CAN Bus Integrity Check

If power and ground are confirmed good, measure CAN bus termination resistance. With the ignition off and the ESC connector unplugged, measure resistance between the CAN High and CAN Low wires at the ESC module connector. The expected value on a properly functioning bus is typically around 60 ohms (two 120-ohm terminating resistors in parallel) — though confirm the exact specification in the factory wiring diagram for your specific BYD variant. A reading that is significantly different suggests a wiring or termination fault elsewhere on the bus.

Step 5 — Monitor ESC Live Data

If the fault is intermittent, use your scanner’s live data view to monitor ESC communication status and wheel speed sensor values while the vehicle is stationary and then during a low-speed test drive. Erratic or freezing values point to the ESC module or its sensors. Total absence of ESC data points to a communication link failure.

Step 6 — ESC Module Testing and Replacement

Only after completing the checks above should you consider the ESC module itself as the fault source. On BYD vehicles, replacement ESC modules typically require programming and calibration to the vehicle — this is not a plug-and-play replacement. A replacement module that is not correctly configured to the vehicle’s VIN and variant data will not function correctly and may generate additional faults.

Is It Safe to Drive With U041681?

The vehicle will generally remain driveable, but with important caveats. Your electronic stability control, traction control, and any ADAS systems that depend on ESC data are either degraded or offline. In normal, predictable driving conditions on dry roads this may not be immediately dangerous — but in emergency manoeuvres, wet or slippery roads, or at higher speeds, the absence of active stability assistance significantly increases the risk of losing vehicle control.On BYD electric and hybrid models, regenerative braking coordination may also be affected, which can alter expected braking feel. Do not ignore this fault. Drive cautiously and avoid high-speed or adverse weather driving until it is resolved.

Repair Cost Estimates (€)

Repair Action	Estimated Cost (€)
Full diagnostic scan and inspection (specialist)	€80 – €150
Wiring repair or connector replacement	€100 – €300
ESC module replacement + programming	€400 – €900+
CAN bus harness repair (extensive)	€200 – €600

Costs vary significantly by BYD model, region, and whether work is performed at a BYD dealer or a specialist independent garage with BYD diagnostic capability. Programming a replacement ESC module generally requires dealer-level tooling or an equivalent professional diagnostic platform.

Related Codes to Check Alongside U041681

When diagnosing this fault, also look for these related codes which may indicate a broader pattern:

• U0415 — Invalid Data Received From Anti-Lock Brake System Control Module (ABS shares the same physical module on many BYD platforms)
• U0100 — Lost Communication With ECM/PCM — points to a CAN bus-wide disruption if stored alongside U041681
• U0121 — Lost Communication With Anti-Lock Brake System (ABS) Control Module — a total loss of the ESC/ABS node rather than invalid data
• C-codes from the ABS/ESC module itself — internal ESC faults that may be generating the invalid data seen by other modules

A cluster of U04xx codes across multiple modules almost always points to a bus-level fault, not simultaneous module failures. A single U041681 in one module points more specifically toward the ESC node or its immediate wiring.

Frequently Asked Questions

Can a basic ELM327 OBD2 reader read BYD U041681?

Generic ELM327-based readers will often not retrieve BYD manufacturer-specific codes like U041681. They may show a generic U0416 or nothing at all. A BYD-compatible professional scanner, or a tool that supports BYD’s proprietary protocol extensions, is needed for complete fault code retrieval and live data access across all modules.

Can U041681 appear after a car wash or water exposure?

Yes. Moisture ingress into the ESC module connector or the CAN bus wiring is a documented cause of intermittent communication faults, including U041681. If the code appeared after rain, a car wash, or driving through standing water, inspect the ESC module connector and surrounding wiring for moisture before assuming a deeper fault. The code may clear once the connector dries, but any corrosion left behind will cause the problem to return.

Will clearing the code fix the problem?

Clearing the code without addressing the root cause will result in the fault returning — often within the same drive cycle if the underlying issue is still present. Clearing codes is a valid diagnostic step to distinguish active from intermittent faults, but it is not a repair.

Does BYD have any known software updates or campaigns for U041681?

BYD has issued OTA software updates for various electronic systems on their vehicles, and some communication-related faults have been addressed through software revisions. Check with your BYD dealer to confirm whether any applicable software update or service action is available for your specific model and build date before committing to hardware repairs.