Car Dashboard Warning Lights
Explained — Complete Guide
Modern vehicles have 30–80+ dashboard warning lights. This guide explains what each common warning light means, its causes, and how urgently you need to act — with photos for easy identification.
🚗Engine & Powertrain Lights
Check Engine Light (CEL)
🔴 Solid: Moderate | Flashing: STOP NOW
General engine or emissions problem. Also called the Malfunction Indicator Lamp (MIL).
Common Causes:
- Loose fuel cap
- Faulty oxygen sensor
- Spark plug or ignition issue
- Catalytic converter problem
Service Engine Soon Light
🟡 Low
Routine maintenance reminder or minor issue.
Common Causes:
- Oil change due
- Scheduled servicing
- Minor sensor issue
Oil Pressure Warning Light
🔴 CRITICAL
Low engine oil pressure — extremely dangerous. Driving can destroy your engine within minutes.
Common Causes:
- Low oil level
- Oil pump failure
- Engine wear or internal damage
Engine Temperature Warning
🔴 CRITICAL
Engine is overheating. Continued driving will cause severe and irreversible engine damage.
Common Causes:
- Low coolant level
- Radiator failure or blockage
- Thermostat stuck closed
- Water pump failure
Reduced Engine Power (Limp Mode)
🔴 High
Car has entered limp mode — the ECU has restricted engine output to prevent further damage.
Common Causes:
- Engine or transmission fault
- Critical sensor failure
- Throttle body issue
Emissions Control Warning
🟡 Medium
Problem with emissions system — can fail Singapore vehicle inspection (LTA check).
Common Causes:
- Faulty oxygen sensor
- Catalytic converter issue
- EVAP system leaks
Glow Plug Warning (Diesel)
🟡 Low to medium
Preheating system for diesel engine. Normal before start — if blinking after start, a fault exists.
Common Causes:
- Failed glow plug(s)
- Glow plug relay fault
- Diesel injection system issue
🛑Brake System Lights
ABS / Brake System Warning
🔴 Red brake light = STOP immediately
ABS (anti-lock braking system) fault or brake system failure. Braking performance may be severely reduced.
Common Causes:
- Worn brake pads
- ABS sensor fault
- Brake fluid leak
- Parking brake left engaged
🛞Tyre & Suspension Lights
TPMS / Low Tyre Pressure
🟡 Medium
One or more tyres is significantly under-inflated. Risk of blowout and loss of control, especially at highway speed.
Common Causes:
- Puncture or slow leak
- Valve stem failure
- Temperature change (cold mornings)
- Normal pressure loss over time
🔋Electrical System Lights
Battery / Charging System Light
🔴 High
The charging system is not maintaining battery voltage. Vehicle may shut off without warning.
Common Causes:
- Faulty alternator
- Dead or failing battery
- Loose or broken drive belt
- Wiring fault
🔒Safety & Driver Assist Lights
Airbag / SRS Warning
🔴 High
The SRS (Supplemental Restraint System) has a fault. Airbags and seatbelt pretensioners may not work in a collision.
Common Causes:
- Clock spring fault
- Impact sensor issue
- Airbag module failure
- Loose wiring connector
Traction / Stability Control Warning
🟡 Low to medium
Loss of traction detected, or stability/traction control system has a fault.
Common Causes:
- Slippery road conditions (normal flashing)
- ABS sensor failure
- Steering angle sensor fault
⚡Hybrid & EV-Specific Lights
Hybrid / High-Voltage Battery Warning
🔴 High
Fault in the hybrid drive system or high-voltage battery pack. Requires specialist diagnosis.
Common Causes:
- HV battery degradation
- Inverter/converter fault
- Hybrid system overheating
- Software fault requiring reset
Warning Light On? Let Us Diagnose It.
TTS Performance Auto uses the Autel diagnostic scanner to read fault codes and identify exactly what your warning light means. Located in Yishun, Singapore.
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