AutoCodes – Toyota – P0A73 Toyota

P0A73 Toyota Code - Generator Phase V Current Low

Quick Answer

The inverter converts the high-voltage direct current of the HV battery and the alternating current for the MG1/MG2. Common causes include Faulty Inverter With Converter Assembly, Inverter With Converter Assembly harness is open or shorted, Inverter With Converter Assembly circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: P0A73 Toyota indicates Generator Phase V Current Low.
Common causes: Common causes include Faulty Inverter With Converter Assembly, Inverter With Converter Assembly harness is open or shorted, Inverter With Converter Assembly circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 1,280

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 11, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0A73 Toyota Description

The inverter converts the high-voltage direct current of the HV battery and the alternating current for the MG1/MG2. The inverter contains a three-phase bridge circuit, which consists of 6 power transistors each for the MG1 and the MG2, in order to convert the direct current and the three-phase alternating current.
The HV control ECU controls the actuation of the power transistors.
The inverter transmits information that is necessary for effecting control, such as the amperage and voltage, to the HV control ECU.
The motor inverter current sensors detect the amperage that flows through the V and W phase cables between the inverter and MG1/MG2. The inverter transmits information that is necessary for effecting control, such as the amperage and voltage, to the HV control ECU.
The HV control ECU monitors the inverter current sensors to detect a malfunction in the sensor system.

OBDII Code P0A73 Toyota - Generator Phase V Current Low - AutoCodes.com — P0A73 Toyota Code - Generator Phase V Current Low

What does this mean?

What are the Possible Causes of the DTC P0A73 Toyota?

Faulty Inverter With Converter Assembly
Inverter With Converter Assembly harness is open or shorted
Inverter With Converter Assembly circuit poor electrical connection

How to Fix the DTC P0A73 Toyota?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0A73 Toyota code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0A73 Toyota Code

1. What does the OBDII code P0A73 mean on a Toyota?

P0A73 indicates the hybrid control module has detected a low current in the generator's Phase V circuit, which is part of the hybrid system.

2. What are the common symptoms of the P0A73 code in a Toyota?

Symptoms may include the hybrid system warning light turning on, reduced fuel efficiency, loss of regenerative braking, or limited vehicle performance in hybrid mode.

3. What causes the P0A73 code to appear?

Common causes include a faulty generator (MG1), damaged wiring or connectors in the Phase V circuit, or an issue with the inverter/converter assembly.

4. Can I still drive my Toyota with the P0A73 code?

While you may be able to drive the vehicle, it's not recommended as the hybrid system may be compromised, potentially leading to further damage or reduced performance.

5. How is the P0A73 code diagnosed?

A technician will use a scan tool to check for related codes, inspect wiring and connectors in the generator circuit, and test the generator and inverter for proper operation.

6. How do I fix the P0A73 code on my Toyota?

Repairs may involve replacing the generator (MG1), repairing or replacing damaged wiring, or addressing issues with the inverter/converter assembly.

7. Is the generator the only part that can fail with a P0A73 code?

No, other components like the inverter, wiring, or connectors in the hybrid system can also cause this code.

8. How much does it cost to repair a P0A73 code on a Toyota?

Repair costs vary widely depending on the issue, ranging from a few hundred dollars for wiring repairs to over $2,000 for generator or inverter replacement.

9. Can a weak 12V battery cause the P0A73 code?

A weak 12V battery is unlikely to cause this specific code, as it relates to the high-voltage hybrid system components.

10. Do I need specialized tools to fix the P0A73 code?

Yes, diagnosing and repairing this code often requires specialized tools, like a hybrid-compatible scan tool and safety equipment for working with high-voltage systems.