Prius P0A0D Code: The Common Culprits & How to Fix Them

It doesn’t matter how long you’ve been cruising your Prius. There might still be some components you’ll find strange to understand. Imagine your engine control system detects issues with parts that require prompt attention. One such issue could be the error code P0A0D. What does it mean and what can you do to fix the problem?

Get yourself the best information and enlightenment about this problem as you read through this article. I’ve also offered information about the fixes.

What Does Error Code P0A0D Mean?

The engine code P0A0D is an indication that your car’s high-voltage system has an electrical issue. This often affects the system’s main relay and the hybrid system. Once a disconnection is detected by the engine control module, the hybrid system automatically shuts down. Thus, the engine control module sets code P0A0D.

There are two subcodes under the P0A0D:

P0A0D – 350: This notifies you that the problem came up while the car was stopped and will possibly render the car inoperative. 

P0A0D – 351: This indicates that the problem came up while the car was in motion. Thus, the car will not become inoperative immediately. 

The interlock safety connector, in most cases, is installed right above the power module or close to the high-voltage system (12 volts). If the interlock safety connector is disconnected in any way, the high-voltage system shuts down automatically. 

The service plug grip, frame wire, inverter terminal cover and two engine wires linked to the inverter with converter assembly are essential components. 

If they become disconnected, the signal line of the battery interlock becomes open or broken. Under this condition, your vehicle will show error code P0A0D, and all efforts to start the vehicle will likely fail.

The reason is that it can be dangerous if the system turns on while the circuit is broken. Therefore, to avoid accidents, electric shocks or even death, the high-voltage system goes off.

In effect, if the car is working, the engine control system alerts the driver very quickly right before the high voltage system turns off (P0A0D -351). Through the vehicle’s dashboard, the driver becomes aware of the issue and then figures out a corrective response.

Causes of Engine Code P0A0D

The possible causes of engine code P0A0D include the following;

  • Service plug grip problem: A lack of grip from the spark plugs can cause the engine not to produce enough torque and horsepower that’s needed. Hence, the code P0A0D will pop up. 
  • Inverter terminal cover problem: When driving, your vehicle needs the direct current turned to alternating current. This transition happens with the help of the inverter terminal. When the terminal cover is defective, the device won’t control the torque or speed of the car.
  • Bad inverter with converter assembly: The same symptoms occur if there’s an issue with the inverter assembly. The inverter offers power and stabilizes voltage. A faulty inverter assembly forces the inverter to burden more load than its capacity.
  • Faulty engine control module: It’s a no-brainer that you won’t be able to start your car once the engine control module goes bad. The engine might cut once the ECM is faulty, preventing you from starting the automobile again.
  • Defective or disconnected frame wire 
  • Electrical disconnection associated with Inverter with converter assembly
  • Too much voltage within the inverter may shut down the hybrid system

How To Fix code P0A0D

An OBD-II is a device that can help you read diagnostic trouble codes (DTCs), like engine code P0A0D and other related codes. If a warning light or Check Engine light appears on your dashboard use an OBD-II to check the problem and ascertain the DTC. 

The following steps will help you fix the code P0A0D once it displays on your instrument cluster:

Step 1: You can begin by taking safety precautions to prevent injuries or shocks. Remember to put on your insulated gloves. 

Step 2: You can now disconnect the service plug grip. 

Step 3: It is advised to wait for some minutes before operating on the HV system, to get the high voltage capacitor in the inverter with converter assembly discharged first.

Step 4: Ensure the battery fuse is properly inserted.

Step 5: Check all connectors associated with the frame wire, service plug grip and inverter terminator cover. This includes the inverter with converter assembly and the HV battery interlock control socket. Check if the 2 wire harnesses connected to the HV battery interlock control socket are well fixed.

Step 6: Inspect for a corroded harness or if the interlock harness is damaged. Endeavor to change the corroded harness as soon as it is discovered. 

Step 7: Inspect all components and change damaged, worn out or bent parts, especially the pins. 

Step 8: Check the powertrain control module to be sure it’s in good condition.


Are P0A0D -350 and P0A0D- 351 the same problem?

Although they both point out the same trouble area, each indicates the condition under which the problem was triggered.

How much will I fix Prius engine code P0A0D cost?

The cost of repairing Prius P0A0D varies, depending on factors like location, the underlying cause of the car’s issue and the engine type. Basically, the charges range between $70 and $160 per hour. 

Can I fix the problem myself?

Fixing engine code P0A0D isn’t that easy and demands expertise, as some tools will be needed to diagnose and fix the problem. If you do not have a fundamental knowledge of how mechanical components work, leaving the job to an expert will be in your best interest. 

Final Thoughts

Prius P0A0D means high voltage system interlock circuit high. The error code requires urgent attention and could cause your Prius to stall or refuse to start. Other symptoms include the appearance of a warning light or engine light on your dashboard. Do not panic if your car comes to a halt. Simply reach out to a qualified mechanic to help diagnose and resolve the issue without delay.

  • James Smith

    I'm James Smith, a car enthusiast and a content writer for Daily Car Tips. I have a passion for all things cars, from classic muscle cars to the latest electric vehicles. When I'm not writing about cars, you can usually find me tinkering with my car or checking out the latest automotive trends.

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