Engine Control System Malfunction

What it means

This is a code specific to Lexus (and the Toyota group); the same number may mean something else on other makes. Many Lexus owners see a CHECK VSC message together with the check engine light, and the reason is that the stability control computer stored this code after the engine computer reported a fault. The stability system itself is usually fine, and the repair starts with the engine code.

Models covered: Lexus models with VSC/TRAC.

Related codes: P0455P0300P0171P0420

Symptoms4

• CHECK VSC message or VSC indicator on the dash.
• Check engine light on.
• Traction and stability control temporarily disabled.
• Usually no change in brake pedal feel.

Possible causes5

• A code stored in the engine computer, such as evaporative emission (EVAP) codes after refueling with the cap left loose.
• Misfire or fuel mixture faults.
• Oxygen sensor or catalytic converter codes.
• Throttle body or throttle sensor faults.
• Communication fault between the two computers (rare).

How to diagnose4

1. Read the engine computer codes before any brake checks.
2. If the message appeared right after refueling, tighten the fuel cap until it clicks.
3. Diagnose and repair the engine code using its own page.
4. Clear codes in the engine and stability computers; some cases need several drives before the engine light turns off by itself.

How to fix4

1. Tighten the fuel cap or replace a damaged cap.
2. Repair the cause of the stored engine code.
3. Repair communication between the computers if no engine code is present.
4. Clear the codes and confirm the CHECK VSC message is gone after a drive.

Repair cost

In Saudi riyals; the highlighted part is the expected range for this fault.

The fix can be almost free by tightening the fuel cap, or just the cost of a cap; it rises depending on the real engine code.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions