The check engine light will come on if the fuel pressure is insufficient.

The check engine light will come on if the fuel pressure is insufficient.

• A. True
• B. It depends on the engine
• C. False
• D. Only when the fuel tank is nearly empty

Answer: (C)

The check engine light comes on when the engine computer detects a fault and stores a diagnostic trouble code. Low fuel pressure can cause drivability problems, but the light doesn’t automatically illuminate just because pressure is insufficient. The ECU will trigger the light only if it detects a fault condition tied to the fuel system and records a code. Sometimes low pressure can occur briefly or without triggering a fault code, so the light may stay off. Therefore, stating that the light will always come on is not accurate.

The check engine light comes on when the engine computer detects a fault and stores a diagnostic trouble code. Low fuel pressure can cause drivability problems, but the light doesn’t automatically illuminate just because pressure is insufficient. The ECU will trigger the light only if it detects a fault condition tied to the fuel system and records a code. Sometimes low pressure can occur briefly or without triggering a fault code, so the light may stay off. Therefore, stating that the light will always come on is not accurate.