AutoCodes – Lexus – P0C77 Lexus

P0C77 Lexus Code - Hybrid Battery System Precharge Time Too Short

Quick Answer

The inverter contains a three-phase bridge circuit, which consists of six power transistors (IGBTs) each for MG1 and 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: P0C77 Lexus indicates Hybrid Battery System Precharge Time Too Short.
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 1,361

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 Feb 13, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P0C77 Lexus Description

The inverter contains a three-phase bridge circuit, which consists of six power transistors (IGBTs) each for MG1 and MG2. The inverter converts high-voltage direct current from the HV battery into three-phase alternating current for generator (MG1) and motor (MG2); it also converts three-phase alternating current supplied by generator (MG1) and motor (MG2) into direct current for the HV battery. The MG ECU controls the actuation of the power transistors (IGBTs). The inverter transmits information necessary for control, such as amperage and voltage, to the MG ECU.

OBDII Code P0C77 Lexus - Hybrid Battery System Precharge Time Too Short - AutoCodes.com — P0C77 Lexus Code - Hybrid Battery System Precharge Time Too Short

What does this mean?

What are the Possible Causes of the DTC P0C77 Lexus?

Faulty Inverter with converter assembly
Inverter with converter assembly harness is open or shorted
Inverter with converter assembly circuit poor electrical connection
Faulty Power management control ECU

How to Fix the DTC P0C77 Lexus?

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 P0C77 Lexus 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 P0C77 Lexus Code

1. What does the OBDII code P0C77 mean on a Lexus?

P0C77 indicates that the hybrid battery system's precharge time is shorter than expected, suggesting a potential issue with the precharge circuit or related components.

2. What are the common symptoms of code P0C77 in a Lexus?

Common symptoms include the Check Hybrid System warning light, reduced hybrid system performance, and possible failure to start the vehicle.

3. What causes the P0C77 code to appear on a Lexus?

Possible causes include a malfunctioning hybrid battery precharge relay, issues with the precharge resistor, damaged wiring, or a fault in the hybrid control module.

4. Can driving with code P0C77 damage my Lexus?

Yes, continued driving with this code could lead to further damage to the hybrid system or leave the vehicle unable to start.

5. How is the P0C77 code diagnosed on a Lexus?

Diagnosis typically involves checking the hybrid battery precharge system components, inspecting wiring and connectors, and testing the precharge relay and resistor for proper operation.

6. Can a weak hybrid battery cause the P0C77 code?

While a weak hybrid battery is not the primary cause, it can contribute to system instability, which might trigger this code.

7. How do you fix the P0C77 code on a Lexus?

Repairs may include replacing the precharge relay, repairing or replacing damaged wiring, replacing the precharge resistor, or addressing faults in the hybrid control module.

8. Is the P0C77 code unique to Lexus hybrid vehicles?

While P0C77 is most commonly associated with Lexus and Toyota hybrids, other hybrid vehicles may also use this code for similar issues.

9. How much does it cost to repair the P0C77 code on a Lexus?

Repair costs vary based on the root cause but may range from $200 to $800 or more, depending on whether the precharge relay, resistor, or other components need replacement.

10. Can I reset the P0C77 code without fixing the issue?

While the code can be cleared temporarily, it will likely reappear unless the underlying problem with the hybrid battery precharge system is resolved.