The RAM Cummins diesel pickup truck features a comprehensive instrument cluster designed to keep you informed of critical engine and vehicle systems. With its 6.7L turbo diesel engine, the cluster includes specific indicators for diesel aftertreatment and fuel management that are essential for proper operation.
RAM Cummins diesel pickup truck Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Master Warning (Stop) | RED | A critical engine or brake fault has been detected in your RAM Cummins diesel that requires immediate shutdown to prevent damage. | Safely stop the vehicle and turn off the engine; contact your RAM dealer. | |
| Check Engine (MIL) | AMBER | The engine control module has detected a fault in the Cummins engine, emissions, or aftertreatment system that may affect performance or emissions. | Have the RAM diagnosed with a scan tool as soon as possible; continue driving with reduced power if flashing. | |
| Glow Plug / Preheat | AMBER | The glow plugs are preheating the combustion chambers for cold starting; wait until the light goes out before cranking the Cummins diesel. | Turn key to 'Run' and wait for light to turn off, then start engine. | |
| DPF / Regeneration | AMBER | The diesel particulate filter is in active regeneration to burn off soot; this is normal but high exhaust temperatures may be noticed. | Drive at highway speeds if possible to complete regeneration; if light stays on, service DPF. | |
| DEF / AdBlue | AMBER | The Diesel Exhaust Fluid level is low or quality is poor, which can lead to power derate if ignored in your RAM Cummins. | ||
| Water in Fuel | RED | Water has accumulated in the fuel/water separator, which can cause injection pump damage on your Cummins diesel. | Drain the water separator immediately; if light persists, replace fuel filter. | |
| Low Fuel | AMBER | Fuel level in your RAM Cummins is low; refuel soon to avoid running the diesel injection system dry. | Add diesel fuel at next opportunity. | |
| Engine Oil Pressure | RED | Engine oil pressure is critically low in the Cummins, which can cause severe engine damage if not addressed. | Stop engine immediately; check oil level and look for leaks. | |
| Battery / Charging | RED | The charging system is not maintaining battery voltage; the alternator or battery may be failing. | Check battery connections and alternator; seek service soon. | |
| Coolant Temperature | RED | Engine coolant is overheated; this can cause serious damage to your Cummins diesel engine. | Pull over safely and let engine cool; check coolant level. | |
| Transmission Temp | AMBER | Automatic transmission fluid temperature is high; reduce load to avoid transmission damage in your RAM. | Stop or reduce speed; let transmission cool. | |
| Brake System | RED | Hydraulic brake pressure is low or there is a fault in the brake system; braking performance may be reduced. | Check brake fluid level; have brakes inspected immediately. | |
| ABS | AMBER | The anti-lock brake system has a malfunction; normal braking is available but ABS may not engage on this RAM. | Have ABS system checked; no immediate stop required. | |
| Airbag (SRS) | RED | The supplemental restraint system has a fault; airbags may not deploy in a crash. | Have airbag system serviced immediately. | |
| Seat Belt | RED | Driver or passenger seat belt is not fastened; a chime will also sound in the RAM. | Fasten seat belt. | |
| High Beam | GREEN | High beam headlights are activated; use only when appropriate to avoid dazzling other drivers. | Dim when approaching oncoming traffic. | |
| Reduced Power (Limp Mode) | AMBER | Engine power is reduced to protect the Cummins due to a detected fault; typically accompanied by a check engine light. | Have vehicle diagnosed at a RAM dealer soon. | |
| Air Filter | AMBER | The engine air filter restriction is high; this reduces performance and fuel economy in your Cummins diesel. | Replace air filter. | |
| Fuel Filter / Water Separator | AMBER | The fuel filter needs replacement or water has been detected in the separator; ensure clean diesel supply to the engine. | Replace fuel filter and drain water separator. | |
| High Exhaust Temp (HEST) | AMBER | Exhaust system temperature is high, typically during DPF regeneration; avoid parking over dry grass or flammable materials. | Continue driving; if light persists, check for faults. | |
| Washer Fluid Low | AMBER | Windshield washer fluid level is low; refill to maintain visibility. | Add washer fluid. |
21 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Glow Plug Failure
Common causes
- Faulty glow plug
- Blown fuse in glow plug relay
- Wiring damage
What to do
Inspect and replace faulty glow plug(s) in your Cummins; check relay and fuse. Consult a RAM technician.
DEF Quality Issues
Common causes
- Using non-certified DEF
- Contaminated DEF
- DEF crystallization in tank
What to do
Drain and replace with fresh, certified DEF; have the system purged at a RAM dealer if needed.
DPF Regeneration Stuck
Common causes
- Frequent short trips preventing regen
- Faulty exhaust temperature sensor
- Excessive soot buildup
What to do
Drive at highway speeds to complete regeneration; if light persists, forced regen may be required by your RAM dealer.
Water in Fuel System
Common causes
- Contaminated diesel fuel
- Condensation in fuel tank
- Failed fuel separator
What to do
Drain water from the fuel/water separator immediately; if light remains, replace fuel filter and have fuel system dried out.
Fuel Filter Clogging
Common causes
- Neglected fuel filter replacement
- Poor fuel quality
- Bacterial growth in diesel
What to do
Replace fuel filter and add anti-bacterial additive; flush fuel system if contamination is severe.
Frequently Asked Questions
How often should I add DEF to my RAM Cummins diesel?
DEF consumption varies, but typically you'll need to refill every 5,000 to 10,000 miles; the low-level warning gives ample mileage to refill.
What does the glow plug light mean in cold weather on my Cummins?
It indicates the glow plugs are preheating the cylinders; do not crank until the light goes out to ensure a quick start.
Is it safe to drive with the DPF regeneration light on?
Yes; the light indicates active regen, which is normal. If it stays on after a long drive, service may be needed.
Why does my RAM show 'Water in Fuel' after refueling?
The fuel you purchased may have been contaminated with water; drain the separator and avoid that station in future.
Can I drive with the reduced power light on?
You can drive at limited speeds, but have the vehicle diagnosed soon to prevent further issues with your Cummins engine.
How do I perform a parked DPF regeneration on my RAM?
Parked regen is typically only done by dealers; for the driver, simply driving at highway speeds triggers active regen automatically.