The largest online repair guide library for every car

About us
Contact support
FAQ
Sign up
Sign in

2023 R1T regen braking feels weak and inconsistent

0

Mike T. · rep 0 · May 25, 5:05 AM · 1 replies · solved · Question

Vehicle: 2023 Rivian R1T Explore

My 2023 Rivian R1T Explore has recently started having very inconsistent regenerative braking. Sometimes it feels strong and normal, but other times, especially after a cold start or during longer drives, it feels significantly weaker, almost like coasting in a traditional ICE car. This makes one-pedal driving difficult and unpredictable.

There are no warning lights on the dash, and the regular friction brakes work fine. I've checked the settings, and it's still set to "High" for regen. The battery state of charge is usually above 20%, so it shouldn't be limited by a full battery.

Is this a software bug, or could there be an issue with the motors or inverter affecting regen performance?

✓ Accepted solution

ClearTheCode Admin

ClearTheCode Team · rep 0 · May 25, 5:05 AM

0

ClearTheCode admin answer:

Inconsistent regenerative braking on your 2023 Rivian R1T can be frustrating, especially if you rely on one-pedal driving. While some variations in regen are normal, significant and unpredictable changes warrant investigation.

Normal Factors Affecting Regen:

  1. Battery State of Charge (SoC): If the battery is nearly full (e.g., above 90-95%), the system will reduce regen to prevent overcharging.
  2. Battery Temperature: A very cold battery will have reduced regen capability to protect the cells. Similarly, an extremely hot battery might also see limitations.
  3. Motor Temperature: If the drive motors are overheating, regen might be reduced to prevent further heat generation.

Potential Issues (if not due to normal factors):

  1. Motor Controller (Inverter) Malfunction: The inverters control the motors for both propulsion and regen. A fault in one or more inverters could lead to inconsistent regen performance.
  2. Brake System Sensor Fault: Although your friction brakes work, a sensor that communicates with the regen system (e.g., brake pedal position sensor) could be sending incorrect signals, causing the system to think you're using friction brakes more than you are, or limiting regen prematurely.
  3. Battery Management System (BMS) Anomaly: A subtle issue with the BMS might cause it to intermittently limit energy input to the battery, affecting regen, even if it's not severe enough to trigger a fault light.
  4. Software Glitch: An intermittent software bug affecting the regen algorithm or sensor interpretation could certainly be a culprit. This is often resolved with an OTA update.

Diagnostics:

Without a warning light, specific OBD codes might not be present. However, a Rivian service center can check for:

  • Pending or historical codes: Even if not active, past events might be logged.
  • Live data: Monitoring battery temperature, motor temperature, inverter status, and brake sensor inputs can reveal inconsistencies.

When to See a Shop:

  1. Monitor & Document: Pay close attention to when and under what conditions the inconsistency occurs (e.g., specific temperatures, duration of drive, battery SoC). This information is valuable for technicians.
  2. Check for Updates: Ensure your R1T has the latest software. Rivian frequently pushes updates that address driving dynamics and system optimizations.
  3. Schedule Service: If the issue is persistent, unpredictable, and not explained by normal operating conditions (like cold battery), it's best to schedule a service appointment. While not immediately dangerous if friction brakes are working, inconsistent regen can impact driving feel and efficiency, and could be a precursor to a larger issue.
Menu

Help & account