What it means
The standardized definition identifies a circuit malfunction for the second left traction control solenoid. The control module sets the code when it detects a fault in that solenoid circuit; the vehicle-specific diagnostic procedure determines the exact setting conditions.
How it works
The left TCS solenoid #2 is an electrically controlled valve in the traction-control hydraulic system; it helps the brake control module manage braking at the left wheel. C0146 is set when the module detects an electrical fault in the second left solenoid circuit, though the exact detection criteria vary by vehicle.
Common causes
Most likely first.
- Open or short in the solenoid circuit
- Damaged wiring or connector
- Faulty solenoid
- Fault in the brake control module
Symptoms
- Traction control warning light
- ABS or stability control warning light
- Traction control may be unavailable
How to diagnose it
- Read freeze-frame data and all ABS or traction-control codes, and note whether the fault is current or stored.
- Inspect the left TCS solenoid #2 connector and its harness for corrosion, loose pins, chafing, or damage near the brake hydraulic unit.
- Use live data or the vehicle-specific output test, if available, to check whether the module can command left solenoid #2 and whether the fault returns.
- With the circuit isolated as directed by service information, check for opens or shorts between the module and the left solenoid #2; compare readings with the manufacturer’s specification.
- Test the solenoid itself and verify its power, ground, and module-side connections before considering a brake control module fault.
Common fixes
- Reconnect and clean the left solenoid #2 connector if its contacts are dirty or loose.
- Repair an open or short in the left solenoid #2 wiring.
- Replace the left TCS solenoid #2 if it fails the specified electrical test.
- Repair or replace the brake control module only after its output and connections are confirmed faulty.
Can I keep driving?
You can usually drive cautiously if braking feels normal, but ABS, traction control, or stability assistance may be unavailable. Avoid slippery roads and hard braking where possible; arrange diagnosis promptly because wheel-slip control may be reduced.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.