P0A77 OBD Error Code: Problem & Solutions

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There’s an OBD-II code P0A77 flashing, and you’re getting anxious on what it means and how to resolve it? Well, don’t worry, we have your back and put down all the important information you need to know about the error, and how to resolve it. This is a generic code and is set by the high voltage control module of your vehicle called the Engine Control Unit. The ECU sets this code when it notices a failure of the current monitoring sensors, after the code is set, the check engine light will also light up.

The inverter present in your vehicle is responsible for converting the high-voltage direct current of the HV battery as well as the alternating current for the MD1/MG2. There are three-phase bridge circuits present in the inverter, and there are sic power transistors present in each of the MG1 and MG2. ECU controls the actuation of the power transistors, when the inverter transmits all the necessary information (eg. amperage and voltage) to the ECU. When the ECU notices a malfunction in the inverter current sensors, the P0A77 code will be set.

What causes this problem with the Generator Phase W Current High?

• Fault present in the Inverter With Converter Assembly
• Harness of the Inverter With Converter Assembly is open or shorted
• Circuit of the Inverter With Converter Assembly has poor electrical connection

1. Inverter with Converter Assembly - Look for repairs and see If the P0A75 code is resolved after fixing the issues, otherwise you will have to replace the inverter with converter assembly.
2. Inverter with Converter Assembly Harness - Repair otherwise replace the harness if the repairs don’t solve the P0A75 code.
3. Engine Control Unit - Try to fix the issues with your ECU through repairs, if that’s not helping, you will have to opt for replacement. Order Online easily at Parts Avatar, simply select the ECU compatible with your vehicle's year of manufacture, make and model and place your order. We ship in just a matter of days!
4. Motor Inverter Current Sensors - Check if you can repair and fix the sensors otherwise go for replacement to get rid of P0A75 error.
5. Powertrain Control Module - Easily replace the PCM from Parts Avatar, order online and avail free shipping on orders above CAD $99, we don’t have any hidden shipping charges in our products, so worry not and order away!
6. Diagnostic Tools - Very important to have the best in hand for diagnosis, At Parts Avatar you can find ones that fit your budget and needs. Order easily from your home and receive your order at your doorstep.
7. Engine Control Module - In case you have to replace the ECM don’t worry you can find reliable brands with warranty. Search for the ECM compatible with your vehicle and place order, our customer care agent is available online 24/7 to help you out!
8. High Voltage Battery - Find the perfect battery for your vehicle. Choose from the wide variety that we have stocked. You can have your order delivered to your home in just a matter of days!

Knowing the symptoms to error code P0A77 will help you pick up what may be causing the problem in the first place. We at Parts Avatar have listed out few common symptoms associated with Generator Phase W Current High.

Common Symptoms

• Service Engine Soon Warning Light is on
• High voltage system is not working

Here are some ways with which you can correct the P0A77 code:

• Repair or replace the damaged wiring, connectors, harnesses and circuits
• Repair or replace High Voltage battery
• Repair or replace the ECU
• Repair or replace the diagnostic tools that aren’t working properly

There is no need to get strained if your OBD Code is still flashing up as we are here at your service. Have a look at our superior variety of Inverter With Converter Assembly, Inverter With Converter Assembly Harness, HV Battery, Engine Control Module (ECU), Motor Inverter Current Sensor and many more. Now all your problems would vanish within no time.

The diagnosis of P0A77 are not that complex, but it’s important to follow the steps and not sip any of them. If at all you think you won’t be able to do it on your own and need professional help, then feel free to approach a professional vehicle diagnostician for it and resolve your issue properly. However, if you want to solve it yourself then follow the steps below:

Start off by procuring your OBD scanner and connect it to the diagnostic port of your vehicle. Make sure you retrieve all the codes and freeze fame the data also, remember to make note of them all in the order of appearance. If you are able to find any codes set prior to P0A76, then you will have to resolve them first. Previous codes can cause other error codes to set as well, so it’s important that they are taken care of first. After making note of all the codes, clear them and take your vehicle on a test drive to see if the code resets or if the PCM enters readiness more. If the latter happens, then you are having an intermittent condition, this condition may have to worsen before accurate diagnosis can be made. If the code is reset, then you will have to start your diagnosis, the first step is to check all of the electrical system connected with this issue.

Start by checking of all the wires, circuits, connectors, harnesses etc. for damages like burning, breaks, corrosion, short etc. If you are able to find any of these issues, simply repair and correct them or opt for replacement. After you have sorted the circuitry you will have to clear the codes and again go on a test drive. Wait to see if the code returns or not (PCM enters readiness mode).If you find that the code is reset, then you will have to check all the parts pertaining to this problem. For this you will require your specific vehicles Technical Service Bulletins or TSB. Match them to the year of manufacture, make, model and engine. Once you have found it, match the symptoms and the error code P0A77 and see what diagnostic steps are mentioned in the TSB. Apart from having diagnostic steps the TSB will also have details of the parts and components related to this error. All the manufacturer specified configurations will also be present. Use the directions given by the TSB to fix your problem, the connector pin-out charts, and circuit flow charts etc will be extremely helpful and enable you to avoid any misdiagnoses.

Common Mistakes When Diagnosing the P0A77 Code

• Skipping steps in the Diagnostic procedure
• Falsely Concluding an issue with the ECU when the wires may be damaged and require repairs/replacements