RAM 2500 Dashboard Warning Lights

These are the dashboard warning lights for the pickup truck RAM 2500 and heavy duty RAM 3500. Listed are the most important RAM 2500 / 3500 warning lights along with an explanation of their meaning and what action to take based on the manufacturer’s guidelines.

This includes some modern systems that older versions of the RAM truck may not have. Dashboard display design and warning light location will vary depending on your version model and year of manufacture.

Airbag Warning Light

The RAM 2500 / 3500 airbag warning light stays illuminated for between 4 to 8 seconds as a bulb check when the ignition is switched to on. The light remains illuminated along with an audible alert if a fault has been detected with the airbag. The usual reason why the airbag light stays on is due to crash sensors, the seat belt buckle not securely clipping int place or sometimes the cables / connection to the seat belt pretensioner under the front seats has become dislodged.

Brake Warning Light

The RAM 2500 / 3500 brake warning light comes on due to either the parking brake being applied or if the parking brake is off and the brake warning light remains lit, then the brake fluid level is low or that there is a problem with the Anti-Lock Brake System reservoir. If the brake fluid is low and requires frequent topping up, it usually indicates a leak in the dual brake system.

If the parking brake is off and the brake fluid is at the correct level, it may indicate a problem with the  brake hydraulic system or a problem with the brake booster has been detected by the Anti-Lock Brake System (ABS) / Electronic Stability Control (ESC) system. An indication that it’s a brake booster fault is that the ABS pump will run when applying the brake and you’ll feel a pulsation through the brake pedal.

ABS Warning Light

The RAM 2500 / 3500 ABS warning light (anti-lock braking system) remaining on means there’s a problem detected. Your truck’s normal brakes will operate as usual, but without the ABS. The usual cause for an ABS failure is one of the wheel speed sensors malfunctioning.

Versions of the RAM 2500 / 3500 that come equipped with ABS will also be equipped with Electronic Brake Force Distribution (EBD). If the ABS and the red BRAKE warning light both illuminate together, it means the EBD system has a fault. EBD distributes brake force to independent wheels allowing for improved braking efficiency. Have your truck brake system serviced immediately.

Coolant Warning Light

The RAM 2500 / 3500 coolant warning light comes on in red indicating an overheated engine condition. If the coolant light comes on while driving, pull over and leave the engine to idle. If the air conditioning is on, switch it off. If the engine temperature does not begin to decrease, switch off the engine as continued operation may cause damage. When engine is sufficiently cool, check coolant levels, water pump / belts and check for leaks.

Oil Pressure Warning Light

The RAM 2500 / 3500 oil warning light comes on when oil pressure in the engine is low. This means that oil may not be circulating and therefore lubricating engine components properly. If the low oil pressure light comes on while driving, pull over and immediately switch off the engine. The low oil pressure light can be a symptom of low oil levels, so check and add oil if required. Only continue to drive the truck if the low oil pressure light goes off as it can otherwise result in severe engine damage.

Oil Temperature Warning Light

The RAM 2500 / 3500 oil temperature warning light comes on when the oil temperature is high. If the light comes on while driving, pull over and switch off the engine as soon as possible. Overheated oil quickly breaks down, losing it’s lubricating properties and leaving deposits inside the engine which may cause damage and increased fuel consumption.

ETC Warning Light

The RAM 2500 / 3500 ETC warning light (red lightening bolt is the Electronic Throttle Control) may stay on or flash when there’s a problem with the electronic throttle control system. If the light come son while driving, pull over, select park and cycle the ignition. If the light remains lit after starting the engine, the vehicle is usually drivable. With the light on, you may experience reduced performance and rough engine idle, know as limp mode or reduced engine power mode.

Have diagnostics on the truck as it may reveal fault codes. Gas pedals are no longer physically connected to the engine throttle which results in failing sensors in the throttle pedal unit, often as a result of wear-and-tear. In newer models, a software update may fix the issue.

Transmission Fluid Warning Light

The RAM 2500 / 3500 transmission fluid warning light comes on when the transmission fluid is high. If the light comes on while driving, pull over and leave the engine to run at idle until the light goes off. High transmission fluid temperatures can be the result of heavy towing, hot weather, old or low fluid levels. Transmission solenoid failing can also cause warning light to come on. Overheating transmission / fluid is a common cause of transmission failure. Have diagnostics to establish fault codes.

Trailer Brake Disconnect Warning Light

This light illuminates when your truck has a trailer connected and the trailer brake has been disconnected.

 

ACC Warning Light

This symbol is the adaptive cruise control fault warning light. When this warning light illuminates, the adaptive cruise control system has malfunctioned. This may be due to the sensor located in the top-center of the windshield. Ensure the area is clear or dirt or snow. If the sensor has become misaligned, it will also trigger the fault light.

Air Suspension Warning Light

The RAM 2500 / 3500 suspension warning light come son when there’s a fault with the air suspension detected. A common fault often relates the the suspension sensor or sensor mount, one located at each wheel. The air suspension payload warning light come on indicate that the maximum payload may have been exceeded or load leveling cannot be achieved at its current ride height. Protection Mode will automatically be selected in order to protect the air suspension system, air suspension adjustment is limited due to payload.

Check Engine Warning Light

The RAM 2500 / 3500 check engine warning light, also known as the malfunction indicator light (MIL) comes on when the truck’s onboard diagnostics system (OBD II) detects a fault. The system monitors the engine and automatic transmissions. If the light comes on while driving, it’s usually safe to continue, if the light remains lit for extended periods, have your truck serviced. The RAM 2500 check engine light can come on for various reasons including:

• Poor quality fuel
• Loose or missing gas cap
• Mass airflow sensor
• Faulty oxygen sensor
• Faulty exhaust gas recirculation valve (EGR)
• Ignition system fault
• Fuel injector blockage
• Fuel pump fault
• Catalytic converter  issues

If the engine warning light flashes, it might indicate an engine misfire that can result in catalytic converter damage. If driving and the engine light flashes, reduce speed and engine load. If the engine light remains lit after engine start or continues to flash, have diagnostics to read fault codes.

ESC Warning Light

‘ESC’ means Electronic Stability Control and is part of the RAM truck’s stability system that helps to improve traction and reduce oversteer and understeer. The ESC light flashes when the system is engaged and operational. If the light remains constantly lit, it means there’s a fault. A typical ESC fault is often related to the wheel speed sensors. ESC can be switched off, though it’s only recommended to do so when trying to free the truck from snow, mud or if attempting to ascend a slippery slope.

LaneSense Warning Light

LaneSense is a warning system to alert drivers when their truck is drifting out of a lane. The system is triggered when a turn signal hasn’t been applied. The LaneSense symbol along with the exclamation point indicates a fault with the system. The system operates by using the camera mounted at the top-center of the windshield.

Low Coolant Warning Light

This radiator symbol illuminates when the Ram Truck’s coolant level is low. It’s usually safe to continue driving, but top up with coolant as soon as possible. For engine coolants, RAM recommends using Mopar Antifreeze/Coolant 10 Year/150,000
Mile (240,000 km) Formula OAT (Organic Additive Technology).

Tire Pressure Warning Light

The RAM 2500 / 3500 tire pressure warning light illuminates for two possible reasons. Firstly, the light remains lit when there’s pressure loss detected in one or more tires, secondly, the light flashes for approximately 1 minutes then remains lit to inform you that there’s a fault with the tire pressure monitoring system (TPMS).

TPMS fault can occur due to the installation of aftermarket tires or wheels on the vehicle that prevent the TPMS from functioning properly. Quite a common reason for TPMS fault is sensor damage when new tires have been installed or aftermarket tire sealants.

The proper cold tire inflation pressure is listed on the driver’s side B-Pillar or the rear edge of the driver’s side door. Cold tire inflation pressure is defined as the tire pressure after the vehicle has not been driven for at least three hours, or driven less than 1 mile (1.6 km) after sitting for a minimum of three hours. 

Service 4WD Warning Light

The service 4WD warning light comes on indicating a fault with the RAM 2500 / 3500 4 wheel drive system. The warning light can occasionally be triggered when driving in snow / icy conditions where it accumulates on the undercarriage of the truck. If the 4WD warning light comes on along with ABS and/or ESC / traction control, a wheels speed sensor issue is common. Another symptom is that cruise control will not work.

Rear Axle Locker Warning Light

The rear axle locker applies to the RAM Power Wagon versions only. The warning light comes on when a fault has been detected with the rear axle locker system. This can occasionally be a wiring connection fault where the link between the two lockers becomes loose.

Tow / Haul Mode Indicator Light

This light illuminates when the RAM 2500 / 3500 tow / haul mode has been activated.

 

Cargo Indicator Light

This symbol illuminates when the truck’s cargo light has been activated.

 

Cold Ambient Derate Mode Indicator Light

This symbol illuminates when cold ambient derate mode has been activated. This is an automatic activation and it means engine power has been reduced to help protect the turbocharger is cold ambient temperatures.

 

Diesel Exhaust Brake Indicator Light

For versions of RAM 2500 / 3500 applicable, the exhaust brake (engine braking) feature supplies negative (braking) torque from the engine. Engine braking is typically used for towing applications where vehicle braking can be achieved by the internal engine power, thereby sparing the mechanical brakes of the vehicle. It is ideal for:

• Vehicle driving control.
• Reduced brake fade.
• Longer brake life.
• Faster cab warm-up.

The yellow light comes on indicating that diesel exhaust brake has been activated and is in full strength mode. An additional green light comes on indicating that diesel exhaust brake has been set to auto.

Air Suspension Alternate Height Indicator Light

This light will illuminate when the RAM 2500 / 3500 air suspension system is set to the Alternate Trailer Height setting.

 

Snowplow Mode Indicator Light

This indicator light illuminates when snowplow mode has been activated.

 

Sway Bar Indicator Light

For RAM Power Wagon versions only, this light will illuminate when the front sway bar is disconnected. If a fault in the sway bar disconnect system has been detected, the sway bar light along with an exclamation point is illuminated

Bed Lowering Indicator Light

This indicator light will illuminate when the Bed Lowering Mode procedure is complete.

 

Ride Height Raising Indicator Light

This warning light will flash and alert the driver that the vehicle is changing to a higher ride height. When lowering, the ride height lowering indicator illuminates

Front and Rear Axle Lock Indicator Light

This indicator light comes on when the front, rear, or both axles have been locked. The symbol will display the lock icon
on the front and rear axles to indicate the current lock status. Alternatively, the rear axle lock symbol illuminates when the rear axle is locked.

4WD Lock Indicator Light

This indicator light comes on when 4 wheel drive lock mode is active. Both front and rear driveshafts are mechanically locked so that the front and rear wheels rotate at the same speed. Alternatively, the 4WD LOW indicator means 4WD is active, but low range provides greater torque and 4WD HIGH means a higher speed and less torque.

Diesel Exhaust Fluid Warning Light

This warning light displays on the RAM 2500 / 3500 dashboard when the diesel exhaust fluid (DEF) is low. The DEF gauge (located on the instrument cluster) will display the level of DEF remaining in the tank.

 

Water in Fuel Warning Light

This warning light displays on the RAM 2500 / 3500 dashboard when water is detected in the fuel filter. If the warning light is illuminated, the water must be drained from the fuel filter before attempting to start the engine, else damage may occur.