OBD-II trouble code
U042D: Invalid Data Received From Active Vibration Control Module
A module is receiving messages from the active vibration control module, but the data inside them is implausible or out of range. The link is alive — the content is wrong. Mostly affects ride smoothness and cabin noise, not driveability.
Quick facts
- System
- Network
- Category
- Network Communication
- Severity
- Low severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $100 – $900
- DIY difficulty
- Shop recommended
Browse every code in U0401–U0478, or start from the full code library.
What does U042D mean?
The active vibration control module manages the systems that cancel out engine and driveline vibration before it reaches the cabin — typically active (electronically controlled) engine mounts, and on some vehicles an active noise-cancellation or active tuned-mass damper setup. It reads engine speed, load, and vibration signals, then commands the mounts or actuators to stiffen, soften, or counter-oscillate so the car stays smooth, especially at idle, during cylinder deactivation, and under changing load. It reports its status to other modules over the communication network. U042D sets when a receiving module is still hearing from the active vibration control module, but the data in its messages is invalid — a value is out of range, implausible, or contradicts what other modules see. The connection is alive; the content can't be trusted. That is the key difference from a lost-communication code, which means the module has gone completely silent.
Because the fault is bad data rather than a dead bus, the causes cluster around whatever makes the module broadcast wrong information. A failing input — an engine-speed or vibration sensor, or the position/pressure feedback from an active mount — can push the module into reporting values other modules reject. On vehicles with vacuum- or solenoid-actuated active mounts, a leaking vacuum line or stuck solenoid can make the feedback data implausible. Low system voltage is a classic trigger, since module logic gets unreliable as voltage sags. The module's own software can be at fault if it is outdated, corrupted, or was never properly programmed after a replacement, and corroded connectors or chafed wiring around the engine bay can corrupt otherwise-good messages in transit.
Symptoms are usually comfort-related rather than driveability-related. You may notice more engine vibration felt through the steering wheel, seat, or shifter — most obvious at idle, at stops with the engine running, or during the transition in and out of cylinder deactivation. There may be a check engine light and, on some vehicles, a chassis or ride-comfort warning. The car stays fully driveable because active vibration control is a refinement feature, not a control system: base engine, brakes, and steering are unaffected. That is why U042D is authored as low severity. Still, worsening vibration can be an early hint of a genuinely failing active mount, so it is worth diagnosing rather than ignoring — and because U042D is frequently a secondary code, read the full list, since a companion mount or sensor code often names the real root cause.
Common causes
- Failing engine-speed or vibration sensor feeding the module bad data
- Leaking vacuum line or stuck solenoid on a vacuum/solenoid-actuated active mount — a perished hose costs a few dollars and produces the same implausible feedback as a failed mount, so it is worth ruling out first
- Faulty active engine mount, or its position/pressure feedback sensor, reporting implausible values
- Low system voltage or a weak battery/charging system
- Corroded connectors or chafed wiring in the engine bay
- Outdated, corrupted, or mismatched active vibration control module software
- Active vibration control module replaced without proper programming
- Electrical noise or damaged bus wiring corrupting messages in transit
Symptoms
- Check engine light, sometimes with a ride-comfort or chassis warning
- More engine vibration felt through the wheel, seat, or shifter, especially at idle
- Rougher idle or noticeable shudder at stops with the engine running
- Vibration during the transition in and out of cylinder deactivation
- Companion active-mount or sensor codes stored alongside U042D
- Vehicle otherwise driving normally — power, braking, and steering unaffected
Diagnostic steps
- 1.Read ALL stored codes first — U042D is often secondary to an active-mount or sensor code that names the bad signal.
- 2.Confirm what the active vibration system uses on this vehicle (active mounts, active damper, or noise cancellation), then focus testing there.
- 3.Check battery and charging system voltage; low voltage is a common cause of implausible module data.
- 4.Use live data to compare the module's reported engine-speed and vibration values against actual conditions.
- 5.On vacuum/solenoid-actuated mounts, inspect vacuum lines and test the mount solenoids for correct operation.
- 6.Inspect engine-bay connectors and wiring to the module and mounts for corrosion, chafing, and loose pins — with the engine off and cool, since the mounts sit low and close to the exhaust and the only way to see them is to put a hand down beside it. If a step needs the engine running to read live data, read it from the driver's seat or a tool on a stand rather than with your hands in the bay: the cooling fan can start on its own and an active mount moves when the module commands it.
- 7.Verify the module has the correct, current calibration, then address any companion codes before condemning the module.
Repair cost
$100 – $900
Cost depends on what is producing the bad data. A split vacuum hose to a mount is the cheap end at a few dollars of hose. Correcting low voltage or a charging fault is $150-$600. A vibration or engine-speed sensor is often $120-$350 installed. An active engine mount is the pricier common case, frequently $300-$700 or more per mount installed depending on the vehicle. A module reflash is usually $100-$300, and active vibration control module replacement with programming is the expensive end at $500-$900 — but that should only follow thorough diagnosis, since U042D is frequently a secondary code.
Estimate your repair
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DIY vs shop
Leave this one to a qualified shop. The barrier here is module programming, security access, and bus-level diagnosis that need manufacturer-grade scan tools and the credentials to use them. DIY attempts often produce a more expensive problem than the original code.