Your Chevy Volt just flashed a message that stops you cold: “Engine Not Available.” Your stomach drops a bit because that sounds serious, right? Before panic sets in, let me tell you something reassuring. This warning isn’t always as catastrophic as it sounds.
Most Volt owners see this message at some point. The good news is that you can often fix it yourself without spending hundreds at the dealership. This article walks you through what’s happening under the hood, why it happens, and exactly how to get your Volt running smoothly again.
What’s Really Going On With Your Volt
The “Engine Not Available” message means your Volt’s computer system has detected something wrong with the gasoline engine’s ability to start or run properly. Think of it as your car’s way of saying, “Hey, I’m having trouble getting the backup engine ready.”
Here’s what makes the Volt unique. Your car runs primarily on electric power from the battery. That gasoline engine? It’s mainly there as a generator to extend your range once the battery runs low. When the system can’t get that engine ready to go, it throws this warning.
You might notice the message pops up randomly while driving, or maybe it appears when your battery charge dips below a certain level. Some folks see it first thing in the morning during cold weather. Others encounter it after their Volt has been sitting unused for a few days.
The tricky part is that your car might still drive fine on battery power alone. But once that battery runs down, you’ll be stuck. Your Volt won’t switch to gasoline power, and that’s when the real problem shows up. Getting stranded isn’t fun, so addressing this sooner rather than later makes sense.
Chevrolet Volt Engine Not Available: Common Causes
Several things can trigger this frustrating warning message. Some are simple fixes you can handle in your driveway. Others need a bit more attention. Let me break down what’s probably going on with your Volt.
1. Stale or Low-Quality Fuel Sitting in the Tank
Old gasoline causes more problems than most people realize. Your Volt might go weeks or even months without burning a drop of gas if you’re doing short commutes on battery power. That fuel sits there, breaking down chemically.
Gas starts degrading after about 30 days. Water vapor seeps in through the tank’s ventilation system. The lighter compounds evaporate first, leaving behind gummy residue that clogs fuel lines and injectors. Your engine control module tries to fire up the engine, can’t get proper fuel flow, and throws the warning.
You might smell a varnish-like odor near the fuel filler cap. That’s a dead giveaway. The fuel gauge might also show questionable readings if moisture has contaminated the tank.
2. Dead or Dying 12-Volt Auxiliary Battery
People forget the Volt has two batteries. Everyone knows about the big lithium-ion pack that runs the electric motor. But there’s also a regular 12-volt battery hiding under the hood, just like in any traditional car.
This small battery powers all your car’s computers, sensors, and control modules. When it gets weak, weird things happen. The engine control module doesn’t get enough juice to run its diagnostics properly. It can’t verify that everything’s ready for the gas engine to start, so it plays it safe and throws the warning.
You might notice other symptoms too. Your dashboard lights might flicker. The infotainment system could act glitchy. Door locks might work slowly. These all point to the auxiliary battery losing its charge.
3. Failed Engine Coolant Temperature Sensor
Your Volt’s computer needs to know the engine temperature before it tries starting the gas motor. That’s where the coolant temperature sensor comes in. It tells the computer whether the engine is cold, warm, or hot, so the fuel mixture and timing can be adjusted accordingly.
When this sensor fails, it sends bogus readings. The computer might think the engine is frozen solid when it’s actually at normal temperature. Or it might report overheating when everything’s fine. Either way, the computer refuses to start the engine because it thinks conditions aren’t safe. Up pops that warning message.
4. Faulty Fuel Pump or Fuel System Pressure Problems
The gas engine needs fuel pressure within a specific range to run properly. Too low, and the injectors can’t spray fuel effectively. The Volt’s fuel pump creates this pressure, pushing gasoline from the tank through the lines to the engine.
Fuel pumps wear out over time. Debris from old gas can clog the pump’s filter screen. Electrical connections corrode. Sometimes the pump itself just gives up after years of cycling on and off.
Your Volt checks fuel pressure before trying to start the engine. If pressure falls below the threshold, the system won’t even attempt ignition. It’s a safety feature that prevents engine damage, but it means you’re stuck with that warning message until you fix the underlying issue.
5. Software Glitches in the Powertrain Control Module
Modern cars are basically computers on wheels. Your Volt’s powertrain control module runs complex software that manages when and how the gas engine engages. Sometimes this software gets confused.
A corrupted memory sector might cause false error codes. An interrupted software update could leave things in a weird state. Sometimes the module just needs a reset, like rebooting your computer when it starts acting strange. The hardware is fine, but the software thinks something’s wrong and triggers the warning message as a precaution.
Chevrolet Volt Engine Not Available: DIY Fixes
Let’s get your Volt back to normal. These solutions range from super simple to moderately involved. Try them in order, starting with the easiest fixes first. Most Volt owners can handle these without special tools or mechanical expertise.
1. Add Fresh Fuel Stabilizer and Run the Engine
Start by addressing fuel quality issues. Drive to a gas station and fill your tank with fresh premium fuel. Premium isn’t always necessary for the Volt, but it helps clean things out. Add a bottle of fuel system cleaner or stabilizer while you’re at it.
Now you need to force the gas engine to run, burning through some of that old fuel. Put your Volt in Mountain Mode if you have a first-generation model. On newer Volts, use Hold Mode instead. These settings make the engine kick in regardless of battery charge level.
Drive around for at least 20 minutes, keeping your speed steady between 45 and 55 mph. This gives the engine time to reach operating temperature and cycle fresh fuel through the entire system. The injectors get cleaned, the fuel lines get flushed, and combustion chambers burn off any deposits. After this drive, park and let everything cool down. Turn the car off completely, wait five minutes, then restart. Check if the warning message has cleared.
2. Test and Replace the 12-Volt Auxiliary Battery
Pop your hood and locate the small rectangular battery near the firewall. You’ll need a multimeter for this test. Set it to measure DC voltage.
Touch the red probe to the positive terminal and the black probe to the negative terminal. A healthy battery should read between 12.4 and 12.8 volts with the car off. Anything below 12.2 volts means your battery is getting weak. Below 12 volts? It’s definitely done.
If the battery tests low, replacement is straightforward. Disconnect the negative cable first, then the positive. Remove the hold-down bracket, lift out the old battery, and drop in a new one. Reconnect positive first, then negative. Your Volt might act weird for the first few minutes after battery replacement as systems reinitialize, but this is normal.
3. Reset the Powertrain Control Module
Sometimes your Volt’s computer just needs a fresh start. This process clears temporary error codes and resets all the control modules. Start by turning off your car completely.
Disconnect the negative terminal on your 12-volt auxiliary battery. Wait exactly 15 minutes. This drains residual power from all the electronic modules, forcing them to clear their memory. Some people only wait five minutes, but 15 gives you better results.
Steps for a complete reset:
- Turn off the car and remove the key
- Pop the hood and locate the auxiliary battery
- Disconnect the negative battery cable
- Wait 15 full minutes without touching anything
- Reconnect the negative cable firmly
- Close the hood and start the car
Your infotainment system will need to relearn some settings. The radio presets will be gone. But the engine warning might disappear completely.
4. Check and Clean the Fuel System Components
This fix requires a bit more mechanical confidence but stays within DIY territory. You’re checking fuel pressure and looking for obvious problems in the fuel delivery system.
Many auto parts stores loan out fuel pressure test kits for free. Connect it to the test port on your fuel rail (consult your owner’s manual for location). Turn the ignition to “on” without starting the car. The fuel pump should prime, and you should see pressure build to around 60 psi. Anything significantly lower suggests pump problems.
Check all visible fuel line connections under the hood for cracks or leaks. Look at the rubber hoses for signs of dry rot. Smell around for gasoline odors that indicate a leak. If everything looks good but pressure is low, the fuel pump likely needs replacement. That’s still doable at home with the right tools, but many people prefer letting a mechanic handle it since it involves dropping the fuel tank.
5. Inspect and Test the Coolant Temperature Sensor
The coolant temperature sensor usually sits near the thermostat housing. It’s a small electrical component that screws into the cooling system. You can test it with a multimeter and verify it’s sending reasonable signals.
With the engine cold, disconnect the sensor’s electrical connector. Set your multimeter to measure resistance (ohms). Touch the probes to the sensor’s terminals. At room temperature, you should see resistance around 2,000 to 3,000 ohms. Compare this reading to the specifications in your service manual.
If the reading seems way off or you get no reading at all, the sensor has failed. Replacement costs about 20 dollars for the part. Drain some coolant first so you don’t make a mess when you unscrew the old sensor. Thread in the new one, reconnect the electrical plug, top off the coolant, and you’re done. Start the car and see if the warning disappears.
6. Update or Reflash the Vehicle Software
GM released several software updates addressing the “Engine Not Available” message for various Volt model years. Your local Chevrolet dealer can check if any updates apply to your specific vehicle. Some updates are free recalls, while others might involve a diagnostic fee.
You could also try software updaters available through the MyChevrolet app or OnStar services, though major powertrain updates usually require dealer equipment. If you’re comfortable with automotive electronics, some independent shops with GM-compatible scan tools can flash updates for less than dealer prices.
7. Contact a Certified Chevy Technician
If you’ve tried everything and that stubborn message won’t go away, professional diagnosis makes sense. A qualified technician has access to GM’s proprietary diagnostic software, which reads detailed error codes your basic code reader can’t access.
Sometimes the problem involves sensors or modules buried deep in the engine bay. Replacing certain components requires special tools or procedures beyond typical DIY abilities. A good mechanic can pinpoint the exact issue within an hour of diagnostic work, saving you from throwing parts at the problem blindly.
Wrapping Up
That “Engine Not Available” message looks scary on your dashboard, but now you know it’s usually fixable without major expense or drama. Start with the simple stuff like fresh fuel and a battery test. Most of the time, one of these basic fixes does the trick.
Keep your Volt’s gas engine running occasionally, even if you rarely need it. Monthly drives on the highway help keep fuel fresh and systems lubricated. Your hybrid will thank you with fewer mysterious warning messages and more reliable performance overall.