C06A0

Code

Generic C — Chassis

Steering Assist Control Module — Hardware Fault

Brand: Generic

Type: C — Chassis

Views: UK: 24 EN: 22 RU: 19

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Internal component failure in the steering assist control module (motor driver, power stage, processor)
Damaged or intermittent power supply (blown fuse, poor battery/alternator voltage)
Poor or corroded ground connection at the module chassis ground
CAN bus communication errors or network wiring faults
Water intrusion or corrosion inside the module or connector
Shorts or opens in wiring harness to module (pins damaged, chafing)

Symptoms

Steering/EPS warning lamp illuminated
Reduced or complete loss of electric power steering assist (heavy steering)
Intermittent assist (assist works then drops out)
Stored DTC C06A0 in the steering assist module
Possible service messages on dash (e.g., 'Power Steering Fault')
Unusual noises from the steering assist motor or module area (if motor driver is failing)

What to check

Read and record all stored DTCs, freeze-frame data and pending codes from all modules (steering, BCM, ABS, ECU)
Verify battery voltage at rest and during cranking (should be ~12.4–12.8 V at rest; >= 13.5 V with engine running)
Inspect steering module connector for corrosion, bent pins, water ingress, or contamination
Check relevant fuses and fusible links for continuity
Scan CAN bus traffic for module presence and error frames (use OEM scan tool or CAN logger)
Measure power and ground pins at the steering module connector for proper voltage and low-resistance ground

Signal parameters

Module supply voltage: nominal battery voltage (approx. 11–16 V depending on state); low or missing indicates power fault
Ignition-switched 12 V supply present when key ON (verify voltage on module ignition feed)
Module ground:
CAN High / CAN Low: differential pair should show ~2.5 V idle each (2.4–2.6 V typical) and toggling with traffic
CAN bus activity: module CAN ID should be present on bus when key ON (use scope/scan tool)
Steering torque sensor/angle input values: within expected ranges and not saturated or implausible (compare live data with other nodes)

Diagnostic algorithm

Safety: Park vehicle, wheels straight ahead, follow OEM safety procedures for working on steering system. Disable vehicle start/operation if steering assist is unreliable.
Retrieve codes from steering assist module and related modules. Record freeze frame and occurrence conditions.
Clear codes and attempt to reproduce. Note whether C06A0 returns immediately or after certain events (temperature, vibration, vehicle start).
Check battery condition and measure module supply voltage at the module connector with key ON and engine running. Repair charging/battery issues first.
Inspect connector and wiring: disconnect module connector, inspect pins for corrosion, bent pins, water, or overheating signs. Repair or replace damaged terminals.
Check fuses and fusible links that feed the module. Replace any blown fuses and inspect for root-cause shorts.
Verify grounds: measure resistance between module ground pin and battery negative/chassis. Clean/tighten ground connections as necessary.
Verify CAN network: using a scan tool or CAN scope, confirm module is present on bus and exchanging messages. Look for bus errors, high error frames, or missing IDs. Repair wiring/terminations if bus faults exist.
Perform module power/ground and signal pin voltage checks per wiring diagram. If power or ground is absent/intermittent, trace harness to source and repair.
If wiring and supplies are good but C06A0 persists, consider module internal hardware failure. Check for manufacturer service bulletins or known module updates.
If repair requires module replacement, follow OEM procedure for module programming/coding and perform steering system initialization/calibration as specified.
After repairs, clear codes and verify proper operation under road test and re-scan for recurrence.

Likely causes

Poor power/ground to the steering assist control module (most common)
CAN communication loss or intermittent messages to/from module
Internal power stage or motor driver component failure
Corroded/wet connector causing intermittent internal fault
Blown fuse or fusible link feeding the module

Fault status

⚠️ Status

Steering Assist Control Module reported an internal hardware fault. Electric power steering assist may be reduced or disabled until fault is resolved.

🔴 Repair difficulty: Hard

⏱️ Diagnostic time: 1–3 hours