The situation when Toyota Prius 20 Refusing to start often causes panic in the owner, but in the case of a hybrid, this does not always mean a fatal engine failure. Unlike classic machines, here the start is controlled by complex electronics, and the lack of starter sound is the normal behavior of the system, not a sign of malfunction. Before calling a tow truck, it is necessary to conduct an initial diagnosis to understand which node is blocking the start.
Most often, the problem lies in the discharge of the auxiliary 12-volt battery, which powers the onboard network and controls the contactors of the high-voltage battery. If the dashboard does not light the indicators READY or flashing a red triangular (alarm), the fault-finding algorithm will be different from the case when the machine is simply silent. Understanding the logic of the hybrid plant Hybrid Synergy Drive This will save time and money on the diagnosis.
In this article, we will discuss in detail all possible scenarios of failure of the launch, from the banal withered “finger” battery to serious problems with the inverter. You will learn how to properly light up the hybrid, what errors on the display are considered critical and why the gasoline engine may not start even with a working traction battery.
Diagnostics of 12-volt battery and READY system
The most common reason why Prius 20. not started, is the discharge of an additional battery with a voltage of 12 volts. This small battery, located in the trunk on the right (or under the hood in newer versions, but in the 20th body usually in the rear), is responsible for turning on the car's "brains." If its voltage is not enough to close the main contactors in the high-voltage battery, the machine will not go into readiness.
Pay attention to the dashboard: if you press the button POWER Only the yellow indicator of the car with the key lights up or the green indicator of the key flashes, and the inscription READY It doesn't appear, so the hybrid hasn't started. The internal combustion engine (ICE) in hybrids is not started by a starter in the classical sense, but by an electric motor-generator. MG1This requires a high voltage through the inverter. Without a 12-volt circuit, this process is not possible.
⚠️ Note: If you hear clicks from under the seat or from the trunk when trying to turn on, but the car stalls or does not go into READY mode, in no case do not try to spin the engine with a starter using classical methods. This can damage the inverter’s electronics.
Check the status of the terminals of the 12-volt battery. Often, oxidation of the contacts or weakening of the nuts leads to a drop in voltage under load. Even if the light bulbs in the cabin burn brightly, the initiation current for activating the high-voltage system may not be enough. Measure the voltage at the terminals: it should be not lower than 12.5 V at rest.
Problems with High Voltage Track Battery (HVB)
If the 12-volt battery is in good condition, Prius 20. still does not start, suspicion falls on the traction nickel-metal hydride battery. A high-voltage battery (HVB) consists of many modules, and failure of even one cell can block the operation of the entire system. The car’s computer constantly monitors the voltage of each module, and if a critical imbalance is detected, it prohibits starting.
A symptom of problems with VVB is often that the machine may be in mode. READY, travel a few meters or seconds, and then deafen with the characteristic sound of the contactors opening. On the dashboard at the same time lights up red triangular and the inscription Check Hybrid System. In some cases, the car may go into emergency mode, allowing only low speed travel, but re-starting after a stop will become impossible.
Battery resource at Prius 20
The average service life of the original battery is 10-15 years or 300-400 thousand km of mileage. However, deep discharge with prolonged downtime (more than 2-3 months without recharging) can irreversibly damage the cells, making it impossible to start without replacing the modules.
For accurate diagnosis of the state of VVB, a scanner is required to read the error codes and the balance of cells. Independently, without equipment, you can only visually assess the condition of the fan cooling battery located in the cabin. A dust-clogged fan is a common cause of overheating and subsequent battery failure, which leads to the inability to start.
Inverter and control system errors
Inverter in Toyota Prius 20 performs the function of converting high voltage direct current into variable for electric motors and vice versa during recovery. If the Inverter Control Unit (IPM) detects a malfunction, the system blocks the start for safety purposes. A common cause is overheating or breakdown of transistor modules.
When the inverter fails, a red triangle with an exclamation mark usually lights up on the instrument panel, and sometimes an overheating indicator. The machine can make a short squeak when turned on, but the mode READY It won't. It is important to note that problems with the inverter are often accompanied by errors in the cooling system, as it has its own circuit with antifreeze and an electric pump.
| Error code (example) | Description of the problem | Possible solution |
|---|---|---|
| P0A78 | Failure of the generator/motor drive | Diagnosis of the inverter, checking the windings |
| P0A94 | The DC-DC Converter Error | Replacement of converter or 12V battery |
| P3000 | Battery management error | Balancing or Replacement of WBB Modules |
| P0A0F | Engine failed to start. | Checking the ignition system and MG1 starter |
If you find a leak of coolant from under the hood in the area of the inverter, you can not start the car. The hit of antifreeze on high-voltage contacts can cause a short circuit and fire. In such cases, evacuation and defective cooling systems are required.
Periodically check the level of antifreeze in the inverter circuit (a separate tank with pink liquid). Its fall can lead to overheating of the electronics and failure of the launch.
Gasoline engine: mechanical and fuel causes
Although the hybrid is started by an electric motor, the start of the gasoline engine is required to move and charge the battery. 1NZ-FXE (1.5 liters). If a READY system is in place but the ICE is not catching when trying to charge the battery or under load, the problem may be the fuel system or ignition. Engine. Prius 20 It operates on the Atkinson cycle, which makes it sensitive to fuel quality and candle condition.
A common cause of failure is throttle contamination or valve malfunction VVT-i. It is also worth checking the fuel pump: if it does not create the right pressure in the ramp, the engine will not start. Unlike conventional cars, there is no classic starter, so you will not be able to “twirl” the engine in the usual way - it will either start with a jerk from the MG1, or will not start at all.
- 🔌 Ignition plugs: Check the gap and the charcoal. For Prius 20 Replacement of candles every 30-40 thousand. In the area of mileage, the use of iridium candles is mandatory.
- ⛽ Fuel filter: Built into the gas pump module. If the filter is clogged, the pressure in the system drops, and the engine stalls or does not start.
- 🌡️ Temperature sensor: Incorrect readings of the coolant sensor can block the launch in the cold season, since the ECU does not see warming up.
If the engine makes extraneous knocks or grinds when trying to start, stop trying immediately. This may indicate problems with the HRM chain or crankshaft inserts, although for motors Toyota This is rare with timely service.
Safety system and ignition key
Sometimes the cause is banal and lies in the immoblazer system. If the car does not see the chip key, the launch will be blocked. V Prius 20 Keyless access is used, and battery discharge in the key or interference in the cabin can lead to the fact that the machine will not go into mode. READY. The key indicator on the panel will flash green.
Try to hold the key close to the logo Toyota on the steering wheel or to the start button to amplify the signal. Also check if there are any sources of strong radio interference (powerful transmitters, other keys, electronics). If the second key is in the car, put it away, as the system can get lost between two signals.
⚠️ Note: If you have replaced the 12V battery and reset the settings, the system may need time to sync. Don’t panic if the first launch goes away with a delay or errors that disappear after the restart.
Algorithm of actions when trying to start ("Lightning")
If you find out that the problem is in the stagnant 12-volt battery, the car can be started by the method of “lighting” from another car or starter. V Prius 20 Under the hood there are special contacts to connect the plus and minus terminals on the body, which simplifies the process, since you do not need to get to the battery in the trunk.
It is important to observe polarity and sequence of actions so as not to damage the sensitive electronics of the hybrid. After connecting the donor, you need to wait a few minutes to recharge the small battery before trying to turn on the mode. READY.
☑️ Checklist launch with a dead 12V battery
After a successful launch, do not stop the car immediately. Allow the system to charge the 12-volt battery and recharge the traction battery if necessary. The hybrid drive contributes to faster charging than parking, as the engine operates in optimal efficiency mode.
The main rule: Never try to start the Prius "from the pusher" or the classic starter from another car directly to the starter. The current is only supplied to the 12-volt network to power the electronics.
Frequently Asked Questions (FAQ)
Why does the Prius 20 not start in the winter in the cold?
In severe frosts (below -25 ° C) thickens the oil, and the 12-volt battery loses capacity. Electronics can block the start due to low voltage. It is recommended to store the car in a warm garage or use a preheater for a 12V battery.
Can I drive a Prius if I don’t start a gasoline engine?
Only if the battery charge allows. However, you can not drive for a long time without a working internal combustion engine, since the battery will quickly sit down and the car will stand up. In addition, the non-working engine does not warm up the catalyst and cabin.
How much does it cost to replace a 12-volt battery with a Prius 20?
The cost depends on the type of battery (AGM or conventional lead-acid) and brand. The average price varies from 3 to 8 thousand rubles for the battery itself, plus the cost of work, if you do not change it yourself.
What if a red triangle is burning and the car is not moving?
It's emergency mode. The error codes must be considered as a scanner. This often indicates problems with the VVB or inverter. Operation in this mode can lead to complete failure of expensive nodes.