AutoCodes – Chevrolet – P1A20 Chevrolet

P1A20 Chevrolet Code - Hybrid Battery System Precharge Time Too Long

Quick Answer

The drive motor generator battery control module is also referred to as the Battery Energy Control Module (BECM). Common causes include Faulty Drive Motor Generator Battery Assembly, Drive Motor Generator Battery Assembly harness is open or shorted, Drive Motor Generator Battery 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: P1A20 Chevrolet indicates Hybrid Battery System Precharge Time Too Long.
Common causes: Common causes include Faulty Drive Motor Generator Battery Assembly, Drive Motor Generator Battery Assembly harness is open or shorted, Drive Motor Generator Battery 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 1,700

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 15, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
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Code P1A20 Chevrolet Description

The drive motor generator battery control module is also referred to as the Battery Energy Control Module (BECM). The drive motor generator battery control module will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is communicated from the drive motor generator battery control module to the Hybrid Powertrain Control Module (HPCM) through serial data. The hybrid powertrain control module is the host controller for Diagnostic Trouble Code (DTC) information.
1. The drive motor generator battery contains 3 high voltage contactors that allow the high voltage Direct Current (DC) batteries to be connected to the vehicle or safely contain the DC high voltage within the drive motor generator battery assembly. The three contactor/relays are a positive high voltage contactor, negative high voltage contactor, and the current limit relay.
2. The power-up sequence for the high voltage DC system occurs in the following order:
3. The drive motor generator battery control module performs a precharge test, by closing both the negative contactor and current limit relay. Because the current limit relay routes the high voltage current through a current limit resistor, the hybrid battery terminal voltage should increase at a steady, predictable rate.
When the drive motor generator battery control module observes that hybrid battery terminal voltage and hybrid battery calculated voltage are at about the same voltage, the motor generator battery control module closes the positive contactor.
With both the negative and positive contactors closed, the drive motor generator battery control module opens the current limit relay.

OBDII Code P1A20 Chevrolet - Hybrid Battery System Precharge Time Too Long - AutoCodes.com — P1A20 Chevrolet Code - Hybrid Battery System Precharge Time Too Long

What does this mean?

What are the Possible Causes of the DTC P1A20 Chevrolet?

Faulty Drive Motor Generator Battery Assembly
Drive Motor Generator Battery Assembly harness is open or shorted
Drive Motor Generator Battery Assembly circuit poor electrical connection

How to Fix the DTC P1A20 Chevrolet?

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 P1A20 Chevrolet 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 P1A20 Chevrolet Code

1. What are the common symptoms of OBDII code P1A20 in a Chevrolet vehicle?

- Common symptoms include difficulty starting the vehicle, reduced power, decreased fuel efficiency, and the illumination of the check engine light.

2. What does the OBDII code P1A20 Chevrolet indicate?

- The code P1A20 indicates that the Hybrid Battery System Precharge Time is too long in a Chevrolet vehicle.

3. What are possible causes of the P1A20 code in a Chevrolet hybrid vehicle?

- Possible causes include a faulty battery precharge relay, issues with the battery management system, high-voltage battery problems, or wiring/connectivity issues.

4. How can I diagnose the source of the P1A20 code in my Chevrolet hybrid vehicle?

- Diagnosing the code typically involves using a diagnostic scanner to retrieve the code, checking the high-voltage battery system for faults, inspecting wiring connections, and testing components like the precharge relay.

5. Can driving with the P1A20 code present cause further damage to the vehicle?

- Continuing to drive with the P1A20 code present can potentially cause damage to the hybrid system components and may lead to further issues with the vehicle's performance and safety.

6. How can I repair the Hybrid Battery System Precharge Time Too Long issue in my Chevrolet hybrid?

- Repair options may include replacing the faulty precharge relay, addressing any issues with the battery management system, repairing wiring/connectivity problems, or seeking professional assistance for a thorough diagnosis and repair.

7. Is it safe to continue driving my Chevrolet vehicle with the P1A20 code until it is repaired?

- It is not recommended to continue driving the vehicle with the P1A20 code present, as it can lead to potential safety hazards and further damage to the hybrid system components.

8. Are there any preventive maintenance measures to avoid encountering the P1A20 code in a Chevrolet hybrid?

- Regularly checking the high-voltage battery system, performing routine inspections, and addressing any issues promptly can help prevent the occurrence of the P1A20 code in a Chevrolet hybrid vehicle.

9. Can I reset the P1A20 code in my Chevrolet without addressing the underlying issue?

- Resetting the code without addressing the underlying issue will only temporarily clear the check engine light, and the problem may persist, potentially causing further issues with the vehicle.

10. How long does it typically take to repair the Hybrid Battery System Precharge Time Too Long issue in a Chevrolet vehicle?

- The repair time can vary depending on the specific cause of the issue, but it may take a few hours to a full day to diagnose and repair the components related to the P1A20 code in a Chevrolet hybrid vehicle.