The Chevy/GMC Diesel S10 pickup or van features a unique set of dashboard indicators tailored to its Isuzu-sourced diesel engine. Known for its simplicity and reliability, this vehicle's warning lights provide crucial feedback for diesel-specific systems like glow plugs and water-in-fuel detection.
Chevy/GMC Diesel S10 Warning Light Symbols
| Symbol | Name | Color | What it means | What to do |
|---|---|---|---|---|
| Glow Plug / Preheat | AMBER | Glow plugs are heating the combustion chambers for cold start; the light turns off when ready. | Turn key to 'Run' and wait for light to extinguish before cranking. | |
| Check Engine (MIL) | AMBER | Indicates a fault in the diesel engine management or emissions system. | Have the system scanned for diagnostic trouble codes. | |
| Water in Fuel | AMBER | Water has accumulated in the fuel/water separator and needs draining. | Drain the water separator located on the fuel filter housing. | |
| Low Fuel | AMBER | Fuel level is low; refuel soon to avoid air in the fuel system. | Fill up with diesel fuel. | |
| Battery / Charging | RED | Charging system voltage is low or battery not charging. | Check alternator belt and connections; test charging system. | |
| Engine Oil Pressure | RED | Engine oil pressure is critically low. | Stop engine immediately and check oil level. | |
| Coolant Temperature | RED | Engine coolant temperature is too high. | Stop engine and allow to cool; check coolant level. | |
| Brake System | RED | Brake hydraulic pressure or fluid level is low. | Check brake fluid level and brake system for leaks. | |
| Parking Brake | RED | Parking brake is engaged. | Release the parking brake before driving. | |
| Seat Belt | RED | Driver's seat belt is not fastened. | Fasten seat belt. | |
| High Beam | BLUE | High beam headlights are activated. | Dim high beams for oncoming traffic. |
11 symbols shown. Icons follow ISO 2575 dashboard standards; exact graphics vary by model year.
Most Important Warning Lights
Low Oil Pressure
Common causes
- Low oil level
- Faulty oil pump
- Clogged oil filter
What to do
Stop engine immediately. Check oil level and add if low; if the light persists, have the oil pressure tested by a diesel mechanic.
Overheating
Common causes
- Low coolant
- Thermostat stuck closed
- Cooling fan failure
What to do
Stop engine and let it cool. Check coolant level and refill if low; inspect for leaks and ensure the fan belt is intact.
Water in Fuel
Common causes
- Contaminated fuel
- Condensation in fuel tank
What to do
Drain the fuel/water separator immediately. If the light remains on, replace the fuel filter and avoid running on contaminated fuel.
Check Engine Light On
Common causes
- Faulty injection pump sensor
- EGR valve issue
- Fuel system problem
What to do
Have the ECU scanned for trouble codes. Common issues include the injection pump timing sensor or a clogged fuel filter.
Battery Light On
Common causes
- Alternator failure
- Loose or broken alternator belt
- Corroded battery connections
What to do
Check the alternator belt tension and condition. Test the charging system output; replace the alternator if not charging.
Frequently Asked Questions
How long should I wait for the glow plug light to go out?
Typically 5-10 seconds in warm weather, longer in cold conditions. Wait until the light goes out completely before starting the engine.
What does the 'Water in Fuel' light mean?
It indicates water has accumulated in the fuel/water separator. Drain it promptly to prevent damage to the injection pump.
Can I drive with the Check Engine light on?
If it's steady and the engine runs fine, you can drive to a repair shop. If it flashes, stop immediately as it signals a misfire or serious issue.
Why does my S10 diesel have no turbo boost gauge?
The naturally aspirated Isuzu diesel engine in most S10s does not have a turbo. Only later models with a turbocharger would include a boost gauge.
What is the proper procedure for cold starting?
Turn the key to the 'Run' position, wait for the glow plug light to go out, then crank the engine. Avoid excessive cranking; if it doesn't start, allow the starter to cool.
How often should I replace the fuel filter?
Every 15,000 miles or more frequently if the water in fuel light comes on. Regular replacement prevents injection pump wear.