What Does U029B Mean?
The control module has lost communication with Drive Motor Control Module C on the vehicle network. This indicates a breakdown in data transfer between modules, typically on hybrid or electric vehicles with multiple motor controllers.
Safety Warning
Vehicle may enter limp mode or become inoperable. Loss of motor control can result in sudden power loss while driving.
Common Causes
35%
Drive Motor Control Module C internal failure or power supply issue
30%
Damaged or corroded wiring harness/connectors to Motor Control Module C
20%
CAN bus network fault affecting Module C circuit
10%
Software corruption or module not programmed correctly
5%
Ground circuit issue specific to Module C
Diagnostic Steps
1
Step 1: Verify power and ground supplies to Drive Motor Control Module C using wiring diagram
2
Step 2: Inspect all connectors and wiring to Module C for damage, corrosion, or loose connections
3
Step 3: Check CAN bus voltage at Module C connector (should see 2.5V on each CAN line with key on)
4
Step 4: Monitor live data for Module C communication status and check for intermittent dropout patterns
5
Step 5: If wiring and power are good, test Module C on another vehicle or replace module and reprogram
Estimated Repair Cost
$300 - $2,500
Parts + labor, varies by vehicle and location
The control module has lost communication with Drive Motor Control Module C on the vehicle network. This indicates a breakdown in data transfer between modules, typically on hybrid or electric vehicles with multiple motor controllers.
The most common cause of U029B (Lost Communication With Drive Motor Control Module "C") is: Drive Motor Control Module C internal failure or power supply issue
Typical repair costs for U029B range from $300 to $2,500, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Vehicle may enter limp mode or become inoperable. Loss of motor control can result in sudden power loss while driving.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U029B to identify the root cause.
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Quick Info
Category
Network
System
Hybrid/Electric Powertrain
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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