What causes a hybrid car not to start?

Most common problems why your Hybrid Mercedes-Benz won’t start. This guide discusses the top 2 causes why a hybrid vehicle won’t start.

Índice Show

Why does my vehicle not start?
Two most common problems with Hybrid Systems
Reminders before you repair the vehicle or let someone repair the vehicle
What is the most common problem with hybrid cars?
How do you start a dead hybrid car?
What do you do when your Toyota hybrid won't start?
What are the signs of the hybrid battery failing?

Why does my vehicle not start?

One reason why your vehicle is not starting is because of the hybrid system failure. Many units on the Mercedes-Benz Hybrid are connected to the high voltage or hybrid system, so if one unit in the high voltage (HV) system is not working, that will bring down the whole HV network and prevent engine start.

For example, if you have a bad AC compressor connected to the hybrid system, that will cause the vehicle not to start because the system is not working properly.

Also, having your vehicle parked for a very long time can cause the battery to wear out. In this case, the hybrid battery will show a 15% charge or below, and that causes the vehicle not to start.

Two most common problems with Hybrid Systems

Power Electronic Module Failure
High Voltage Hybrid Battery Failure

As you can see in the video, almost all vehicles are diagnosed due to a faulty power electronic module.

Hybrid Battery replacement can cost around $15,000, and Power Electronic Module replacement can cost $10,000 to $12,000.

Reminders before you repair the vehicle or let someone repair the vehicle

Diagnosing the vehicle using an advanced scanner
– scanning the vehicle tells the causes why the vehicle is not starting, which will help you ease the work.
Knowing the shop before you let your vehicle in
– before you let the vehicle be repaired know the shop first because many mechanics do not know about repairing a Hybrid vehicle or High Voltage vehicle.
Hybrid Vehicles are high voltage.
– it is better to let someone who can deal (have more knowledge) with high voltage vehicles do the work rather than doing it yourself because the high voltage is dangerous and deadly.

Hybrid Vehicles are great cars, but when it comes to repairing, not all mechanics have the knowledge and can’t work on hybrid vehicles. We have tutorials on replacing the parts, but you must be aware of that when working with high voltage.

High voltage can cause injuries or can also cause death, and that is one of the reasons why many mechanics and repair shops will turn you down and tell you that they don’t want to work on hybrid systems. If you decide to work on hybrid vehicles, you must get training first on how to handle high-voltage electric vehicles.

We hope you find the Top 2 Causes Why A Hybrid Vehicle Won’t Start guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.

Just like regular gasoline cars, not all hybrid systems are created equal and this includes their batteries. Jump-starting any car is dangerous if you do not know what you are doing.

In general, most hybrid vehicles can be jump-started just like a regular car with a conventional gas engine. However, the unusual layout of many hybrids’ powertrains can cause some confusion.

Considerations:

Powertrains are not standardized across the hybrid auto industry, there are variations across brands and even within the same brand over model year redesigns.
Many hybrid cars have more than one battery, and they might not be located where you expect them to be.
Some hybrid cars do need a trip to the dealership if the battery dies.
Some new hybrid models can jump-start themselves.

Most hybrid models have two distinct batteries:

The main high-voltage battery in the powertrain, which takes over when the car is not using its gasoline engine or runs in tandem with the gas engine for better efficiency.
A smaller 12-volt battery tasked primarily with starting the vehicle, which can be located under the hood but is often located in the trunk.

The presence of a hybrid’s high-voltage battery pack is most likely why some people believe it is unsafe or impossible to jump-start a hybrid, but those batteries should be distinctive from the smaller, more conventional 12-volt battery used for starting the car. A hybrid battery pack should be sealed, to prevent electric shocks caused by accidental contact, and should be marked with warning labels. Be extra careful to ensure you are working with the correct battery.

Both of those batteries can drain. If you are having battery trouble, you will have to determine which battery is the source of your problems. If your hybrid car will not start, and jump-starting does not work, you will need a mechanic to look at the main hybrid battery.

Some vehicles feature a jump-start terminal under the hood, which you should use instead of the 12-volt battery. Once you have located this terminal, the steps to jump-start the hybrid are pretty much the same as jumping any other car.

By the way, if you need to use a hybrid car to jump-start another car, the smaller 12-volt battery is what you will need to use. In a lot of hybrids, it is located in the trunk instead of under the hood, and the terminals should be marked with plus (+) and minus (-) posts like the battery of a regular car. If you do not find the battery in the trunk, or see marked terminals for jump-starting, check your owner’s manual.

So far, we have been careful to say that “most” regular cars have a 12-volt battery responsible for starting duty. That is because until 2017, every modern car had such a battery, according to Car and Driver. Instead of the 12-volt battery, some have opted for a lithium-ion battery located next to the main hybrid battery.

Some hybrids are capable of starting themselves, they cannot be traditionally jump-started, nor can they be used to jump-start another car. If the starter battery dies, a switch inside the car, labeled “12V Batt Reset,” pulls enough current from the main hybrid battery to jump the starter battery. In addition to the convenience, the lithium-ion starter battery is 26 pounds (nearly 12 kilograms) lighter than a regular 12-volt starter battery, which helps make these vehicles more efficient.

If you own a hybrid car, your best bet is to familiarize yourself with the jump-starting options and procedures for your make and model before you actually need them. Your owner’s manual is always a good source for this kind of information. You also can contact your dealership’s service department or the manufacturer’s customer service. If you don’t know what you’re doing in an emergency, call a roadside assistance service. That will keep you from getting hurt and not cause permanent damage to your hybrid car’s complicated powertrain.

Threewitt, Cherise. (2018). “Can You Jump-start a Hybrid Car?” Retrieved from https://auto.howstuffworks.com/can-jump-start-hybrid-car.htm.

What is the most common problem with hybrid cars?

One of the typical hybrid car issues is problems with the evaporative emissions system. Usually, problems occur in the form of system failure or leaks. If valves or lines fail, you have to replace the system, but scheduling regular hybrid car maintenance can prevent this issue.

How do you start a dead hybrid car?

Allow the discharged battery to rest with the jumper cables connected for 5 minutes. Then, run the engine in the vehicle that is boosting at about 2,000 RPM with the gas pedal lightly depressed. Start the hybrid system and make sure the “ready” light is on. Disconnect the negative cable and then the positive cable.

What do you do when your Toyota hybrid won't start?

Correcting most no-start problems usually involves replacing the alternator, starter or battery, cleaning connections, ignition system repairs, or fuel system repairs. But because there are so many potential causes, the diagnosis is key to understanding how expensive the repair will be.