AutoCodes – Generic – P0C77

P0C77 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 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 2,051

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

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

What does this mean?

What are the Possible Causes of the DTC P0C77?

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?

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 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.

Need more information about the P0C77 code?

Need more information on how to fix the P0C77 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0C77 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P0C77 Buick — Hybrid Battery System Precharge Time Too Short
P0C77 Cadillac — Hybrid Battery System Precharge Time Too Short
P0C77 Chevrolet — Hybrid Battery System Precharge Time Too Short
P0C77 GMC — Hybrid Battery System Precharge Time Too Short
P0C77 Lexus — Hybrid Battery System Precharge Time Too Short
P0C77 Toyota — Hybrid Battery System Precharge Time Too Short

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 Code

1. What are the common symptoms of OBDII code P0C77 (Hybrid Battery System Precharge Time Too Short)?

The common symptoms include the Check Engine light coming on, decreased fuel efficiency, and potentially reduced hybrid system performance.

2. What are some possible causes of OBDII code P0C77?

Possible causes include a malfunctioning precharge relay, issues with the hybrid battery voltage, or problems with the hybrid battery cooling system.

3. How can I diagnose the cause of OBDII code P0C77?

Diagnosing the cause typically involves using a diagnostic scanner to read the code and then performing further testing on the precharge relay, hybrid battery voltage, and cooling system components.

4. Can I continue driving my vehicle with OBDII code P0C77?

It is not recommended to drive the vehicle with this code present, as it can lead to further damage to the hybrid battery system and potentially affect the vehicle's performance.

5. How can I repair OBDII code P0C77?

Repairing this code may involve replacing the precharge relay, addressing issues with the hybrid battery voltage, or fixing problems with the cooling system. It is recommended to consult a professional mechanic for proper diagnosis and repair.

6. Are there any DIY tips for troubleshooting OBDII code P0C77?

While basic troubleshooting steps like checking the battery connections and fuses can be done, diagnosing and repairing this code usually requires specialized tools and knowledge. It's best to seek help from a qualified technician.

7. How much does it cost to repair OBDII code P0C77?

The cost of repairing this code can vary depending on the root cause of the issue, the extent of the damage, and the labor rates in your area. It's advisable to get a few quotes from different mechanics to compare prices.

8. Can a faulty hybrid battery cause OBDII code P0C77?

Yes, a faulty hybrid battery or issues related to the hybrid battery system can contribute to triggering OBDII code P0C77 due to the precharge time being too short.

9. Is OBDII code P0C77 specific to certain hybrid vehicle models?

While this code is related to hybrid systems, it can be found in various hybrid vehicle models across different manufacturers. It's important to refer to the specific vehicle's service manual for accurate diagnosis and repair information.

10. How urgent is it to address OBDII code P0C77?

It is recommended to address this code promptly to prevent further damage to the hybrid battery system and to ensure the vehicle operates efficiently. Ignoring the code could lead to more severe issues down the line.