ABS and Traction Control Lights On - 2021 Ram 1500 Longhorn

ClearTheCode admin answer:

When both your ABS (Anti-lock Braking System) and Traction Control lights illuminate on your 2021 Ram 1500 Longhorn, it typically indicates a fault within the vehicle's braking or stability control system. These systems are interconnected, so a problem in one often affects the other. Since your basic OBD-II scanner isn't showing codes, it means the issue is likely not powertrain-related but rather within the chassis control modules.

Here are the most common causes and what to consider:

1. Wheel Speed Sensors (WSS): This is by far the most frequent culprit. Each wheel has a sensor that monitors its rotational speed. If a sensor is dirty, damaged, or has a faulty wiring connection, it can send incorrect or no data to the ABS module. This confuses the system, causing both lights to come on. A common scenario is debris or rust affecting the sensor's reading. You might also notice a slight difference in braking feel, though not always.
2. Damaged Wiring or Connectors: Inspect the wiring harnesses leading to each wheel speed sensor. They are exposed to road debris and can get damaged, chafed, or have corroded connectors. A loose connection can also cause intermittent issues.
3. ABS Module Failure: While less common on a newer vehicle, the ABS control module itself can fail. This is a more expensive repair but would definitely trigger both lights. This usually presents with more erratic behavior or complete loss of ABS function.
4. Brake Fluid Level/Pressure Sensor: Although you checked the fluid level, a faulty brake fluid level sensor or a pressure sensor within the master cylinder could potentially trigger these lights, though usually, a dedicated brake warning light would also be present.
5. Steering Angle Sensor: The traction control system relies on the steering angle sensor to know the driver's intended direction. A fault in this sensor can confuse the system and activate the lights.

When to See a Shop:

• Since your basic scanner can't read ABS/Chassis codes, a professional shop with an advanced diagnostic scanner is necessary to pinpoint the exact fault. They can read the specific C-codes (Chassis codes) that your truck is storing.
• If you've visually inspected the wheel speed sensors and their wiring for obvious damage and found nothing.
• If the lights remain on after attempting a battery disconnect (to reset modules, though codes will likely return if the fault is persistent).
• While the truck might seem to drive normally, your ABS and Traction Control systems are currently disabled, which can be a safety concern, especially in adverse driving conditions. It's best to get it diagnosed and repaired promptly.