If fuel pressure is insufficient, the check engine light will come on.

• A. True
• B. It indicates only oil pressure
• C. False
• D. It indicates battery voltage

Answer: (C)

The check engine light comes on when the engine computer detects a fault and stores a diagnostic trouble code. A fuel pressure problem can cause symptoms, but the light isn’t guaranteed to appear every time fuel pressure is insufficient. The PCM only lights the MIL if it detects a fault in the fuel system (or another engine-management issue) and records a code. So low fuel pressure may or may not trigger the light, depending on whether the ECU sees it as a fault. The other options aren’t correct because the light isn’t specifically an oil pressure or battery indicator, and the check engine light isn’t active for every fuel-pressure situation.