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Erratic Regenerative Braking on 2024 Air Pure

0

Mike T. · rep 0 · May 25, 5:14 AM · 1 replies · solved · Question

Vehicle: 2024 Lucid Air Pure

Hello Lucid owners,

I've been noticing some inconsistent behavior with the regenerative braking on my 2024 Lucid Air Pure. Sometimes it feels really strong, almost like I'm hitting the brakes, and other times it's barely there, even when I lift off the accelerator in the same driving conditions.

It's making driving a bit unpredictable, especially in traffic. There are no warning lights on the dash. Is this a known software glitch, or could it be something more serious with the motor control or battery system? I've tried cycling through the drive modes, but it doesn't seem to make a consistent difference.

Any thoughts on what might be causing this erratic regen performance?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 5:14 AM

0

ClearTheCode admin answer:

Inconsistent regenerative braking on your 2024 Lucid Air Pure can be unsettling and points to an issue with how the vehicle's powertrain control module is managing energy recovery. Here's a breakdown:

1. Diagnostics & Common Causes:

  • Battery State of Charge (SOC) and Temperature: Regenerative braking effectiveness is heavily influenced by the battery's SOC and temperature. If the battery is nearly full or too cold/hot, the system will reduce regen to protect the battery. However, if this is happening erratically, it could indicate a faulty temperature sensor or an issue with the BMS reporting incorrect SOC.
  • Brake System Sensors: The vehicle's brake pedal position sensor and wheel speed sensors are crucial for coordinating regenerative and friction braking. A fault in these sensors can lead to miscommunication and erratic regen performance. While less common, issues like C0040 (Brake Pedal Position Sensor Circuit) could be relevant if friction brakes are also involved.
  • Motor Control Unit (MCU) Software Glitch: The MCU dictates how the electric motors act as generators during regen. A software bug or corruption could lead to inconsistent commands, resulting in varied regen strength. This might not always throw a specific OBD code, but could be identified by manufacturer-specific diagnostic tools.
  • Inverter or Motor Fault: While less likely to cause erratic regen without other symptoms, a developing fault in the motor or inverter could subtly affect its ability to generate power efficiently during deceleration.

2. What to Check/Do:

  • Monitor Battery Info: Pay attention to your battery's SOC and temperature readings (if available in the infotainment) when the regen behavior changes. This can help rule out normal operational limitations.
  • Software Updates: Confirm your vehicle has the latest software updates. Lucid often refines powertrain and braking algorithms through software releases.
  • Test in Different Modes: Systematically test regen in different drive modes (e.g., Smooth, Swift, Sprint) to see if the inconsistency is more pronounced in one over another.

3. When to See a Shop:

  • Safety Concern: Inconsistent braking, even if it's regenerative, can pose a safety risk. If you feel the car is unpredictable, it's best to have it inspected.
  • Lucid Service Center: Given the complexity of EV powertrain controls, a certified Lucid service center is the best place to diagnose this issue. They can run comprehensive diagnostics on the BMS, MCU, and braking system. Explain the exact conditions under which the erratic behavior occurs, including SOC, ambient temperature, and driving style.
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