Fault code P0A3E is called “Generator Inverter Over Temperature” but in different programs it may be called differently. This fault designation applies to all vehicles equipped with OBD-II.
Technical description and explained code P0A3E
The OBD-II fault code P0A3E is a generic fault code defined as “alternator inverter overheating”. In this case, the error indicates the specific problem with which the problem occurred.
The alternator inverter/converter is designed to convert the DC current from the high voltage battery into a three phase current designed to operate the motor generator. This is accomplished by a circuit in the control module that estimates the total power consumption.
When the inverter/generator converter assembly in the hybrid vehicle overheats, the engine control module (PCM) recognizes this with sensor information, and the PCM sets code P0A3E.
The inverter/generator converter voltage measurement circuit is designed to monitor the alternator and battery voltages while the vehicle is running. The alternator inverter/converter output voltage should be at the proper level.
This malfunction in the vehicle is due to elevated alternator inverter temperature. When the Powertrain Control Module (PCM) detects that the alternator inverter temperature is too high, code P0A3E will be set.
Symptoms of vehicle malfunctions
The main signal that an error P0A3E has occurred is the Malfunction Indicator Lamp (MIL) is also known as the CheckEngine Light.
It can also be warning signs such as:
- Check engine control lamp on the control panel will light up (the code will be recorded in the memory as a fault).
- The battery check lamp illuminates.
- Some gauges or sensors on the instrument panel may be inactive.
- Problems with starting the engine.
When fault P0A3E appears, the engine may not start, so this code should be considered serious. It is better to correct this error as soon as possible.
Factors that can cause this error code
The error code P0A3E can mean that one or more of the following problems have occurred:
- Generator inverter temperature sensor has failed.
- Faulty alternator inverter/converter.
- Open or short circuit in wiring harness.
- Loose or damaged connectors.
- Poor grounding is a common cause.
- Blown fuse or fusible link.
- Faulty battery.
- Sometimes faulty PCM or programming error is the cause.
How to fix or reset OBD-2 code P0A3E
Some suggested steps for troubleshooting and fix the error code P0A3E:
- Read all stored data and error codes with an OBD-II scan tool. To find out when and under what circumstances fault P0A3E appeared.
- Clear the error codes from the computer memory and test-drive the vehicle to find out if the malfunction appears again.
- If the error code appears again, visually inspect the electrical wiring and control module connector.
- Visually inspect and test the alternator inverter/converter as well as the temperature sensor.
- If necessary, repair or replace the inverter/generator converter and any defective wiring.
- If there are no defects, check the PCM itself and its software part.
Diagnose and repair of problems
When a P0A3E error code occurs, other errors may sometimes be present. Associated codes usually refer to abnormal system voltages. And also to performance range mismatch codes, which may refer to various sensors.
If there are no additional codes, the first thing to do is to check the battery to determine its state of charge and overall performance. If the battery is discharged or damaged, recharge or replace it.
Wiring check
After checking the battery, visually inspect all wiring associated with the inverter/generator converter. If necessary, repair or replace to ensure effective load transfer.
If no visible signs of shorts or other damage are found, use a voltmeter to check resistance and ground. Replace if necessary to ensure that all electrical values are within the limits specified by the manufacturer.
Also locate any fuses that are in any way connected to the charging system. After checking, replace any damaged or suspect fuses.
Testing the alternator inverter
If all the wiring is checked, you need to test the alternator inverter/converter itself with a multimeter. In most cases, a faulty inverter is the cause of error P0A3E.
If the defect is confirmed, replace it with a new or rebuilt unit, as it is almost always more cost-effective than a repair. However, make sure that the unit being replaced is identical to the original in all respects, including mounting brackets and specifications.
After replacement, start the engine and monitor the indicator light on the dashboard to make sure the inverter is working properly. The warning light should go out within a few seconds.
If the charging lamp does not come on, it may be the cause of the error. Therefore, it is necessary to test and troubleshoot the alternator control lamp.
You can also measure the system voltage, it should be between 14.2 and 14.8 volts. Allow the vehicle to run at least one full drive cycle before re-scanning the system. Most likely there will be no P0A3E error, but sometimes additional clearing with the scan tool is necessary.
On which vehicles does this problem occur most frequently
Fault code P0A3E can occur on different vehicles but there are statistics on which brands this occurs most often. Here is a list of some of them:
- Ford (Escape, Fusion)
- Hyundai
Fault code P0A3E can sometimes be found with other errors. The most common are the following: P0A36, P0A37, P0A38, P0A39, P0A3A, P0A3B.
