Car Shuts Off While Driving But No Check Engine Light

Check the engine light to give peace of mind by warning about the underlying issue in the car’s system. But it can be concerning if the car shuts off while driving but no check engine light.

It can happen due to a bad crankshaft position sensor, faulty idle air control valve, or clogged air filter.

A faulty fuel pump or damaged alternator can also cause this alarming issue. So, you should deeply diagnose and physically inspect the problem to fix it instead of continuing to drive.

Causes of Car Shuts Off While Driving But No Check Engine Light

The check engine light is only activated when the ECU gets enough time to log a fault. So, if something happens very quickly, it can stop the engine from running without triggering the CEL.

Regarding the transmission type, your car can stop suddenly if you have the wrong gear in the manual transmission.

In an automatic transmission, it could be empty engine oil in the sump, low oil pressure due to a faulty oil pump, bad alternator, or fuel pump.

The engine can also stall suddenly due to a low level of engine oil, low coolant level, failure of the coolant thermostat, gearbox failure, or battery loose contact. Though stalling is rare for a modern car, if it shuts off frequently, bring it to the service center.

Bad Crankshaft Position Sensor

If your car shuts off randomly while driving, particularly without showing any check engine light, it can result from a damaged crank position sensor on the engine.

It’s a common intermittent problem that doesn’t activate the check engine light. Overheat and vibration from the engine can cause the crankshaft sensor to lose calibration.

So the sensor can deliver an error code to the ECM and shut down the engine.  However, the engine should turn back on after a while.

So, if your car shuts off when driving but starts back up, it’s a clear sign of a damaged crankshaft position sensor.

The crankshaft position sensor is placed on the engine block under and over the oil filter. It’s tough to handle this intermittent problem. So, if it happens at random times, consult with an expert mechanic.

Faulty Ignition Switch

A faulty ignition switch can result in an intermittent loss of power that causes the car to shut down without warning. If the ignition switch is disconnected, the car doesn’t start, but the check engine light will still illuminate.

Wiring or Electrical Issues

Loss or corrosion of wires, connectors, or ground connections may cause intermittent power failure. This will cause the electrical system to malfunction, and the car can turn off without an OBD fault.

A Bad Idle Air Control Valve

A faulty idle air control valve can cause a vehicle to cut out and die. This small valve is found on the engine’s intake system and allows air to enter it, avoiding the mass air flow sensor and throttle body.

The ECU controls it, and the air and fuel ratio is adjusted based on inputs like intake air temperature.
However, the idle air control valve can clog and stop working properly due to age.

If the idle air control valve opens partially or closes completely, it can limit the airflow into the engine and shut off the car.

Faulty MAF Sensor or Throttle Position Sensor

If either the MAF sensor or the throttle position sensor fails, the air-fuel mixture will be off-balance, leading to stalling. But if it’s intermittent or subtle, it won’t cause the check engine to light on immediately.

Vapor Lock or Fuel Vaporization Issues

In a minority of instances, when fuel vaporises in the fuel line (usually in very hot temperatures), this can cause a vapour lock, and you’ll end up stalling. This isn’t going to cause an error code because that’s not a fault the OBD system can identify.

Clogged Air filter

Another minor problem that isn’t covered by the check engine light is the clogged air filter. The air filter can become clogged due to driving the vehicle in a less clean environment and won’t be able to prevent debris from getting sucked into the engine.

So, enough air won’t reach the combustion chamber, which can result in the engine dying suddenly.

Faulty Engine Control Module (ECM)

An out-of-sync ECM or ECU (engine control unit) can also cause the engine to stop intermittently. If the ECM malfunctions, it may be unable to keep the engine running, though this may not always produce a check engine light.

Blocked or Malfunctioning EGR Valve

If your EGR valve clogs, you will stall the car. This valve returns exhaust gases into the engine and can get rough idle or stall out without activating the check engine light if it’s not working correctly.

Faulty Fuel Pump

The fuel pump is one component that doesn’t give any sign before failing. When the fuel pumps fail, fuel can’t enter the engine.

So, a bad fuel pump can suddenly shut off the engine while driving. Check the fuel pump to see if your car stops running while driving and won’t start.

Use starter fluid to verify if the problem is related to the fuel system. If the engine starts fine, the fuel pump needs service.

Bad Alternator

An alternator helps the battery to supply the essential electrical power to the vehicle to keep it running. It also helps recharge the battery to ensure sufficient power while starting the vehicle.

If your car’s alternator fails, the battery won’t get charged consistently and won’t get enough power to keep running. Hence, it can suddenly shut off the car while driving.

The signs of a damaged alternator include dimming headlights and the vehicle not starting. If your car shuts off while driving and the battery light comes on, it’s an obvious sign of a bad alternator.

However, you can drive the vehicle a few miles after alternator failure as the car will use reserve power to perform normally. Once the reserve is finished, the car will shut off.

How To Fix a Car That Randomly Dies While Driving?

Your car can stall while driving without showing any check engine light due to plenty of reasons. So you should diagnose the car to find out and fix the exact reason and fix this concerning issue.

1. Use a Scanner

Get an OBD II scanner tool and plug it into your car’s port. Check your vehicle’s owner’s manual to find the port easily.

Keeping the scanner attached, insert the key into the ignition switch and rotate it to the on position. The car’s dummy light should turn on the dashboard. Don’t run the car while scanning.

2. Read the Code

Within a few minutes, error codes show up on the onboard computer. If the faulty camshaft position sensor is responsible, the display should show the P0340 code. There can also be multiple error codes. If so, you have to work on the individual codes separately.

In this case, you should bring the car to the auto repair shop. Though it’s easier to fix the clogged air filter, bad alternator, or faulty fuel pump, replacing a bad crankshaft position sensor or idle air control valve requires skill.

3. Erase the Code

Before bringing the car to the service centre, you can try to reset the error code and restart the vehicle.

To do this, select erase code on your scanner and press enter. It may take a few moments to erase all the codes stored in the computer. But remember, resetting the code won’t solve the underlying problem.

So your car may shut off after a few miles, days, or weeks. It may put you in bigger trouble and cost more expensive repair. So, it’s always best to inspect the car by an expert mechanic to make the drive safe.

4. Inspect the Battery And Alternator

Battery Terminals: Clean all corrosion around the terminals and connect it properly. Shorted or corrosive terminals may cause intermittent power failure.

Alternator: Make sure that the alternator is charging the battery correctly. A failed alternator will cause you to lose power and not drive properly.

5. Examine the Ignition System

Ignition Switch: If the ignition switch is faulty, the car might suddenly fail to start. The ignition switch can be faulty if you see the dashboard lights dimming or no longer working when you press the key.

Spark Plugs And Wires: Check for broken or worn spark plugs and wires. Outdated spark plugs or wires will not start, and you will eventually stall. Replace them if they’re old or broken.

6. Inspect the Electrical System

Loose or Damaged Wiring: Look for loose or rusted wiring in the wiring harness near the battery, fuse box and engine control unit (ECU). Unsecured or faulty wiring should be repaired or changed.

Ground Connections: Ensure all ground connections (often black wires attached to the car frame) are clean, tight, and not corroded. : Bad grounds can cut the car’s electricity.

7. Clean or Replace the Idle Air Control (IAC) Valve

The IAC valve is the engine’s lurch regulator. When dirty or broken, it can get stuck on the pavement at low speeds. Refill or clean the IAC valve to return to smooth idle and stop.

How To Prevent Future Car Shuts Off While Driving?

• Keep up with regular services such as filters, spark plugs and fluids.
• Maintain clean electric connections and make sure that the battery is working properly.
• Take care of small problems before they become big ones.

If you take these steps, you should be able to pinpoint and repair the issue so your car does not randomly stop.

FAQs on Car Shuts Off While Driving But No Check Engine Light

Final Words

So, if your car shuts off while driving with no check engine light, start troubleshooting with the fuel, oil level, or clogged air filter. These minor problems don’t activate the check engine light while it can shut off the engine.

But if your car stops randomly while driving, look for more serious problems, such as a bad crankshaft position sensor or idle air valve. But don’t just restart the vehicle and decide to keep driving, as it can cause severe problems.