What Does U041C Mean?
The variable valve timing or cylinder deactivation control module (rocker arm control) is sending corrupted data to the engine control system. This prevents proper coordination of valve timing or cylinder deactivation strategies.
Common Causes
38%
Failed rocker arm control module with internal processor or driver circuit failure
26%
Faulty oil pressure sensor or VVT position sensor providing invalid feedback data
20%
Damaged wiring harness or connectors to rocker arm solenoids or sensors
10%
Low engine oil level or pressure causing erratic VVT system operation
6%
CAN bus communication fault affecting module data transmission
Diagnostic Steps
1
Step 1: Check engine oil level and condition; verify proper oil pressure using scan tool or mechanical gauge
2
Step 2: Inspect rocker arm control module and VVT solenoid connectors for oil contamination or damage
3
Step 3: Monitor VVT position sensor and oil pressure sensor data during engine operation at various RPMs
4
Step 4: Test VVT solenoid operation and resistance; verify proper actuation using scan tool active tests
5
Step 5: Check CAN bus communication at rocker arm module; replace module if sensors and solenoids test normal but data remains invalid
Estimated Repair Cost
$250 - $1,500
Parts + labor, varies by vehicle and location
The variable valve timing or cylinder deactivation control module (rocker arm control) is sending corrupted data to the engine control system. This prevents proper coordination of valve timing or cylinder deactivation strategies.
The most common cause of U041C (Invalid Data Received From Rocker Arm Control Module "A") is: Failed rocker arm control module with internal processor or driver circuit failure
Typical repair costs for U041C range from $250 to $1,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Engine may run rough, lose power, or experience reduced fuel economy. While generally safe to drive short distances, continued operation without repair may cause engine damage or catalytic converter overheating. Avoid extended highway driving until repaired.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U041C to identify the root cause.
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Quick Info
Category
Network
System
Variable Valve Timing / Cylinder Deactivation System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
A quality scan tool helps you read codes, view live data, and clear faults.
