U0212 — Lost Communication With Steering Column Control Module

Quick answer

• What the code means: The vehicle's control modules have lost communication with the steering column control module.
• Severity: Get towed; this can affect steering and potentially lead to power steering loss or other safety issues.
• Most common cause: A faulty steering column control module or wiring issues.

What the U0212 code means

The U0212 diagnostic trouble code (DTC) indicates that one or more other control modules in the vehicle have lost communication with the Steering Column Control Module (SCCM). This is a generic communication fault code, meaning it applies to all OBD-II equipped vehicles.

In simpler terms, the various computers in your car, such as the engine control module (ECM) or body control module (BCM), are not able to "talk" to the computer responsible for controlling functions within the steering column. This communication is vital for many vehicle systems, including power steering, turn signals, wipers, and sometimes even the airbag system.

Common symptoms

• Illuminated "Service Engine Soon" or "Check Engine Light" (though not always immediately)
• Loss of power steering assist
• Intermittent or inoperative turn signals
• Wipers not functioning correctly or at all
• Inoperative horn
• Warning lights on the dashboard related to steering or other affected systems
• Difficulty starting the vehicle (in some cases)
• Steering wheel controls (e.g., radio, cruise control) not working

Common causes

1. Faulty Steering Column Control Module (SCCM): The module itself may have failed internally, preventing it from communicating with other modules.
2. Wiring harness issues: Open circuits, shorts, or corrosion in the wiring connecting the SCCM to other modules or to the vehicle's power and ground.
3. Loose or corroded connectors: The electrical connectors to the SCCM or other related modules might be loose or contaminated, disrupting communication.
4. Faulty CAN Bus: The Controller Area Network (CAN) bus is the communication network that allows modules to talk to each other. Issues with the CAN bus itself (e.g., a shorted wire, incorrect termination resistor) can cause communication loss.
5. Low battery voltage: Extremely low battery voltage can disrupt module communication, as some modules require a stable voltage to operate correctly.
6. Software glitches: Rarely, a software anomaly in the SCCM or another connected module could cause a temporary communication loss.
7. Defective other module: While less common, a fault in another module that frequently communicates with the SCCM could also cause the U0212 code if it prevents the SCCM from responding.

How a technician diagnoses it

1. Verify the complaint and perform a visual inspection: The technician will first confirm the symptoms and look for any obvious signs of damage, such as chewed wires, loose connectors, or corrosion.
2. Scan for all DTCs and freeze frame data: A professional scan tool will be used to retrieve all present and pending diagnostic trouble codes, especially U-codes (network communication codes). Freeze frame data will provide a snapshot of vehicle conditions when the code was set.
3. Check for SCCM communication: The technician will attempt to communicate directly with the SCCM using the scan tool. If communication is not possible, it strongly suggests a problem with the SCCM itself, its power/ground, or its connection to the CAN bus. Good communication means the scan tool can access SCCM data streams and perform tests.
4. Inspect power and ground to the SCCM: With a multimeter, the technician will check for proper voltage supply (typically battery voltage, ~12.6V with the engine off, ~13.5-14.5V with the engine running) and ground at the SCCM connector. A bad value would be significantly lower voltage or an open ground.
5. Test CAN bus integrity: Using an oscilloscope, the technician will examine the CAN bus signals at the SCCM connector. They will look for proper waveform patterns and voltage levels (typically varying between 0-5V for CAN High and vice-versa for CAN Low, or around 2.5V reference). A flat line, incorrect voltage, or distorted waveform indicates a bus problem.
6. Perform continuity and resistance checks: The technician may perform continuity checks on the wiring harness between the SCCM and other modules, as well as a resistance check of the SCCM itself and the CAN bus termination resistors (typically around 60 ohms across CAN High and CAN Low).
7. Swap in a known good SCCM (if accessible and programmable): If all other tests point to the SCCM, and the original module is easily swappable, a technician might try installing a known good unit to see if communication is restored. Note: many SCCMs require programming to the vehicle.

Typical repair cost

• Diagnosis: $100 - $200 (can vary based on shop and complexity)
• Wiring repair: $150 - $500 (depending on the extent of damage and location)
• Steering Column Control Module (SCCM) replacement:
  • Parts: $250 - $800 (highly variable by vehicle make and model)
  • Labor: $150 - $400 (plus potential programming costs of $100 - $250)
• Connector repair/replacement: $50 - $200

Can I keep driving with this code?

No, it is not safe to keep driving with a U0212 code. Since this code indicates a loss of communication with the steering column control module, critical safety systems such as power steering, turn signals, and potentially airbags could be affected. Driving with this code could lead to unexpected loss of vehicle control, making it a significant safety hazard. You should have the vehicle towed to a trusted repair shop as soon as possible.

Related codes

• U0100: Lost Communication With Engine Control Module/Powertrain Control Module "A"
• U0121: Lost Communication With Anti-Lock Brake System (ABS) Control Module
• U0140: Lost Communication With Body Control Module
• U0213: Lost Communication With Steering Column Control Module "A"
• U023A: Lost Communication With Image Processing Module "A"