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2023 R1S Regen Braking Feels Inconsistent or Weak

0

Mike T. · rep 0 · May 25, 5:07 AM · 1 replies · solved · Question

Vehicle: 2023 Rivian R1S Launch Edition

I've noticed on my 2023 Rivian R1S Launch Edition that the regenerative braking isn't as consistent as it used to be. Sometimes it feels strong, providing good one-pedal driving, but other times it's barely there, almost like I'm just coasting when I lift off the accelerator.

This inconsistency makes the friction brakes engage more often, which feels different and less predictable. I'm used to the smooth, strong regen of my R1S.

Is this normal behavior for an EV under certain conditions, or a sign of a problem with the system? I haven't seen any warning lights.

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 5:07 AM

0

ClearTheCode admin answer:

Inconsistent regenerative braking on your 2023 Rivian R1S can be concerning, especially when you rely on it for one-pedal driving. While EVs are designed for strong regen, several factors can influence its performance.

Common Causes for Inconsistent Regen:

  • Battery State of Charge (SoC): When the battery is near 100% charged, the vehicle has less capacity to accept energy from regenerative braking. The system will reduce regen to prevent overcharging, relying more on friction brakes.
  • Battery Temperature: Extremely cold or hot battery temperatures can limit regenerative braking efficiency. The battery management system will protect the battery by reducing regen output.
  • Driver Mode Settings: Ensure you haven't inadvertently changed your drive mode or regen intensity settings. Rivian offers different levels of regen.
  • Brake Pedal Position Sensor (BPPS): If the BPPS is faulty, it might incorrectly detect brake pedal input, causing the system to reduce regen or engage friction brakes prematurely.
  • Software Glitch: Minor software bugs can sometimes cause temporary inconsistencies. Ensure your vehicle's software is up to date.
  • Motor or Inverter Issues: Less common, but a problem with the electric motors or their inverters could affect their ability to generate electricity during deceleration.

Potential OBD Codes (if a fault exists):

  • P0A7A: Drive Motor A Inverter Performance (or similar for other motors)
  • C0040: Brake Pedal Position Sensor Circuit Malfunction

What You Can Do:

  1. Check SoC and Temperature: Observe if the inconsistency correlates with a full battery or extreme weather conditions.
  2. Verify Drive Mode: Double-check your vehicle's settings to ensure the desired regen level is selected.
  3. Software Update: Ensure your R1S has the latest software updates, as these often include bug fixes and performance improvements.
  4. Monitor: Pay attention to when and under what conditions the regen feels inconsistent. Does it happen only at certain speeds or after a specific duration of driving?

When to See a Shop:

  • Soon: If the inconsistency is persistent, happens regardless of battery SoC or temperature, or if you notice any associated warning lights (e.g., check engine light, brake system warning). A Rivian service center can perform diagnostics to check for sensor faults, software issues, or deeper powertrain problems. While not an immediate safety hazard if friction brakes are working, consistent regen is crucial for predictable driving and optimal energy efficiency.
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