Most Dash warning lights indicate that a fault has occurred inside the vehicle’s system.
Dash warning lights provide an idea — sometimes precise, sometimes vague — of what’s wrong with a car.
Dash warning lights are only the messenger to something going on and does not pinpoint the item or system that has failed.
As a result, Some of the issues are relatively small. Some of the issues are major.
Unfortunately, there is no way to distinguish between them by just looking at the Malfunction Indicator Light (MIL).
So, The only way to find out what’s wrong with the car is to plug in a OBD scantool.
The scantool and accompanied software can read the Diagnostic Trouble Code (DTC) from the system. Every time the OBD system turns on the Malfunction Indicator Light (MIL) light, it will also store a Diagnostic Trouble Code (DTC) in the electronic control unit. The Diagnostic Trouble Code (DTC) will give more information about the detected issue. Many parts stores will read the code for free.
Dash warning lights are nothing new, but the messages are. There are hundreds of different dash warning lights. The following list of dash warning lights are the most common. Not all warning lights are universal. Always refer to your owner’s manual when you’re not 100% sure what the light indicates.
This is only a small list of what is out there-Dash Warning Lights Information
Check Engine or Malfunction Indicator Light (MIL):
Indicates the engine computer has set a Diagnostic Trouble Code (DTC). Usually requires diagnosis with a professional scan tool.
The Malfunction Indicator Light can signal three different types of problems.
- Occasional flashes indicate temporary engine malfunctions. In this case, it is good to be aware of the possible forthcoming issues which can later on turn to more serious ones.
- The most common case is when the indicator light stays on constantly. This indicates a more serious problem. Yet, sometimes the issues aren’t that serious but can affect the emissions of the vehicle, for example.
- The most serious type of signaling is when the MIL flashes all the time. It is a sign that your vehicle’s engine is misfiring. Because,The issue is a major one you should stop the engine immediately to prevent serious damage.
Most cars have an alternator, along with a voltage regulator, that keeps the battery charged and also provides electricity to the vehicle when the engine is running. A simple circuit looks at the voltage that the alternator is producing, and turns the battery light on if it is low.
Indicates voltage level is below normal level and the vehicle’s charging system is not functioning properly. Check battery terminals, alternator belt, and battery condition.
Coolant Temp Warning:
If you see the coolant light show up on your dashboard, it could mean coolant levels are running low, so check the gauge on the side of the coolant tank under the hood and top up if necessary. In conjunction with a temperature gauge reading well into the red, it could mean your engine is overheating.
Indicates temperature has exceeded normal limits.
- Coolant level
- Fan operation
- Radiator cap
- Also coolant leaks
Transmission is operating at higher than optimum temperature as transmission fluid is hotter than normal. Check transmission fluid level and engine coolant level.
Oil Pressure Warning:
STOP driving immediately and turn the engine off.
Possible Causes of Low Oil Pressure Warning Light:
- A low oil level (check the dipstick)
- Bad oil pump
- Defective oil pressure sending unit
- Oil pressure gauge or warning light switch
If this light stays lit, it indicates loss of oil pressure. Immediately check oil level and pressure.
Oil Change Reminder:
Indicates that oil life has expired.
This is monitored by the ECM:
So, The interval can be mileage or a combination of readings taken by the ECM. The owners manual lists the reset procedure. Some vehicles require the use of special tools to reset the light.
When you first start the engine, the “oil change due” light should come on for 1 to 2 seconds and then go out. If the light stays on, the vehicle is due for an oil and filter change.
Service Vehicle Soon:
Typically indicates a lighting or other electrical problem that is controlled by the BCM (body control module). Check all lights (headlights, turn signals, brake lights, and hazard lights).
The service vehicle soon light comes on when there is a fault condition in an area of the vehicle chassis systems such as—the anti-lock (ABS) brake system, the traction control (TCS) system, the electronic suspension system, or the brake hydraulic system.
TPMS (Tire Pressure Monitoring System):
Consequently, the tire pressure monitoring system has found a tire with low air pressure or there may be a sensor malfunction. Check tire pressure. In addition, Some vehicles will allow manual reset of TPMS warning light and others will require professional diagnosis. Refer to owner’s manual.
Indicates one of three possible conditions:
- Parking brake is on
- Problem with the braking system/brake fluid is low
- ABS problem
If the problem is in the ABS system, it may need a professional diagnosis.
Reduced Power Warning:
Indicates Engine Computer has limited engine power output. As a result, The ECM has many levels of reduced power depending on what component has failed in its control system. Usually requires diagnosis with a professional scan tool.
Indicates that the Anti-lock Brake computer has set a code and needs professional diagnosis.
The ABS system uses sensors at each wheel to monitor their rotational speed. Furthermore, A computer monitors the signals from all four wheels and the position of the brake pedal to make sure that the vehicle is stable and under control.
If the computer notices any abnormal signals, or the lack of a signal from any of the sensors, it will turn the ABS light on, to alert the driver of an issue. In addition to monitoring the wheel speed sensors, the computer can turn the ABS light on for other reasons like low brake fluid levels or a blown fuse.
Consequently, If your fuel cap light is on, it means that the computer has detected a leak in the system, typically from a loose gas cap. A leak present somewhere else in the system can also trick the computer into thinking the gas cap is leaking.
If not addressed, quite often the Check Engine Light will also illuminate.
Indicates that cruise control is set during driving.
Indicates that there is a problem with the vehicle’s traction control/anti-skid or electronic stability system.
So, If the symbol lights momentarily it may mean that the ignition switch is locked and will need the proper transponder-equipped key to re-start. If the symbol is visible when the vehicle is on, then it typically indicates a malfunction in the security system.
Indicates that there is an exterior light on the vehicle that is not functioning properly.
Traction Control or ESP:
This light Illuminates when the vehicle’s traction control/anti-skid or electronic stability system is in use. Usually an indicator that conditions are slippery.
Indicates that a door (including hood and trunk) is not closed. Open and close all doors, including hood and trunk. Consequently, If vehicle is left in this condition overnight it can drain the battery.
This symbol indicates that the vehicle’s overdrive system has been manually turned off. Typically the overdrive system is controlled by an on/off switch.
So, If this light stays illuminated after starting, it indicates that the vehicle has found a fault in the airbag system and the computer has set a code. Professional repair of the supplemental restraint system is highly recommended.
Washer Fluid Reminder:
Indicates washer fluid is low. Fill washer fluid reservoir. The cap has a symbol that looks like a windshield. Some vehicles have separate reservoirs for front and rear window washers.
Indicates that the vehicle’s front fog lamps are illuminated.
So, It could be something as minor as a faulty sensor or a broken wire, but it could be something more serious that, if left unchecked, will cause lasting and expensive damage to your vehicle.
Dash warning lights are not going to warn you that:
- The water pump is about to fail
- That one of the ball joints is worn out
- Or even that the A/C is going to stop blowing cold air in mid-August.