AutoCodes – Buick – P1A20 Buick

P1A20 Buick 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 Buick 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.

Save to My Repairs My Repairs

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

Code Popularity 1,078

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
Comments
Add Comment

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

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

What does this mean?

What are the Possible Causes of the DTC P1A20 Buick?

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 Buick?

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 Buick 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 P1A20 Buick code?

Need more information on how to fix the P1A20 Buick code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1A20 Buick code diagnosed by a professional: Find a repair shop in your area

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 Buick Code

1. What are the common symptoms of OBDII code P1A20 in a Buick related to the Hybrid Battery System Precharge Time Too Long?

- The common symptoms include the check engine light illuminating on the dashboard, reduced hybrid system performance, and potential difficulty starting the vehicle.

2. What are the possible causes of OBDII code P1A20 in a Buick indicating the Hybrid Battery System Precharge Time Too Long?

- The code P1A20 in a Buick can be triggered by issues such as a faulty precharge relay, problems with the high voltage battery, or a malfunction in the hybrid battery control module.

3. How can I diagnose OBDII code P1A20 in a Buick related to the Hybrid Battery System Precharge Time Too Long?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific fault code, checking the hybrid battery system components for any visible damage, and testing the precharge relay and related circuits.

4. Is it safe to continue driving my Buick with OBDII code P1A20 indicating the Hybrid Battery System Precharge Time Too Long?

- It is not recommended to continue driving the vehicle with this code as it can lead to further damage to the hybrid battery system and affect the overall performance of the vehicle.

5. What are some repair tips for addressing OBDII code P1A20 in a Buick related to the Hybrid Battery System Precharge Time Too Long?

- Repair tips may include inspecting and replacing the precharge relay if faulty, checking and repairing any damaged wiring or connections, and resetting the fault code after completing repairs.

6. Can a DIY enthusiast fix OBDII code P1A20 in a Buick indicating the Hybrid Battery System Precharge Time Too Long?

- While some basic troubleshooting steps can be performed by a DIY enthusiast, diagnosing and repairing issues related to the hybrid battery system may require specialized tools and knowledge best handled by a professional technician.

7. Are there any recalls or technical service bulletins related to OBDII code P1A20 in Buick vehicles with Hybrid Battery System Precharge Time Too Long?

- It's recommended to check with Buick dealerships or visit the National Highway Traffic Safety Administration (NHTSA) website to see if there are any recalls or technical service bulletins related to this specific code.

8. What is the typical cost to repair OBDII code P1A20 in a Buick due to the Hybrid Battery System Precharge Time Too Long?

- The cost of repairing this code can vary depending on the underlying issue, but it may involve replacing components such as the precharge relay, high voltage battery, or hybrid battery control module, which can range from a few hundred to a couple of thousand dollars.

9. How often does OBDII code P1A20 occur in Buick vehicles with Hybrid Battery System Precharge Time Too Long?

- The occurrence of this specific OBDII code can vary, but it is not uncommon in Buick hybrid vehicles experiencing issues with the precharge time of the hybrid battery system.

10. Can resetting the fault code associated with OBDII code P1A20 in a Buick resolve the issue of the Hybrid Battery System Precharge Time Too Long?

- Resetting the fault code may temporarily clear the check engine light, but it will not fix the underlying problem causing the code to appear. It's important to diagnose and address the root cause of the issue for a lasting solution.