U0415 on 2021 Ram 1500: Invalid ABS Data Causes and Fixes

What's Unique About the 2021-2021 Ram 1500

For the 5th Generation (DT) Ram 1500, the U0415 code is frequently a companion to other diagnostic trouble codes, particularly those pointing to an internal failure of the ABS module itself (C2200) or low system voltage. A Ram-specific Technical Service Bulletin (TSB #08-037-21) for the 2021 model year with the 3.6L eTorque engine lists U0415 alongside codes for low battery voltage (P0562) and internal processor performance (P060C-00), suggesting that electrical system health and software updates for the Hybrid Control Processor (HCP) are critical factors on these trucks. Furthermore, a massive recall was issued in 2024 for 2019 and 2021-2024 models due to a software malfunction that could cause the ABS control module to disable the Electronic Stability Control (ESC) system.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• ABS warning light illuminated
• Electronic Stability Control (ESC) or traction control warning light on
• "Service Electronic Braking System" message on the dash.
• "Service Trailer Brake System" message on the dash.
• Cruise control may be inoperative.
• 4WD system may be disabled or unavailable.
• In vehicles with air suspension, a "Service Air Suspension System" message may appear.
• Multiple warning lights may appear simultaneously, often described as a 'Christmas tree' effect on the dash.

Most Likely Causes

1. Failing ABS Control Module 🔴 High Probability ABS modules on late-model Ram trucks are a widely documented failure point, often due to internal electronic faults or circuit board issues that lead to corrupted data transmission. This is often confirmed by the presence of code C2200-49 for internal electronic failure. 🎬 See how to diagnose and fix the common C2200 module failure.
   How to confirm: A professional scan tool will often show other codes, like C2200, indicating an internal module fault. Diagnosis involves ruling out all other possibilities (wiring, power, software) before condemning the module. A technician may try to re-flash the module before recommending replacement.
   Typical fix: Replace the ABS control module. This requires programming the new module to the vehicle's VIN and configuration using a tool like AlfaOBD or the dealer's wiTECH software. In many cases, only the electronic part of the module is replaced, avoiding the need to bleed the brakes.
   Est. part cost: $250-$800
2. ABS Module Software/Firmware Issue 🔴 High Probability Stellantis issued a major recall in August 2024 for over 1.2 million 2019 and 2021-2024 Ram 1500s for a software malfunction that could cause the ABS module to disable the ESC system. TSB 08-037-21 also points to a software update for the HCP on 3.6L eTorque models as a fix for a group of codes including U0415.
   How to confirm: A dealer or a shop with a wiTECH scan tool can check the vehicle's VIN against open recalls and check the current software calibration of the ABS module against the latest available version.
   Typical fix: Update the ABS control module software. This must be done at a dealership or a qualified independent shop.
   Est. part cost: $0 (if covered by recall/warranty) - $200 (for labor)
3. Low Battery Voltage or Charging System Fault 🟡 Medium Probability Modern trucks with numerous electronic modules are highly sensitive to voltage fluctuations. A weak battery, especially in models with eTorque, can cause communication errors between modules, leading to codes like U0415. TSB #08-037-21 explicitly links U0415 to low voltage conditions (P0562).
   How to confirm: Test the battery with a digital multimeter or a load tester. A resting voltage below 12.4V indicates a weak battery. Check the alternator output while the engine is running (should be 13.5V-14.5V). Many owners on forums report that random warning lights are the first sign of a failing battery.
   Typical fix: Replace the battery and ensure battery terminals are clean and tight. If the alternator is faulty, it will need to be replaced.
   Est. part cost: $150-$400
4. Wiring Harness or Connector Issue 🟡 Medium Probability The wiring harness to the ABS module or wheel speed sensors can be damaged by road debris, improper repairs, or corrosion at the connector pins. A user on RamForum.com reported getting U0415 and C2200 codes immediately after hitting a tire on the highway, suspecting wiring damage.
   How to confirm: Visually inspect the wiring harness leading to the ABS module (located in the driver's side front wheel well area) and to each wheel speed sensor for any signs of chafing, melting, or corrosion. Check for a secure connection at the ABS module plug.
   Typical fix: Repair the damaged section of wiring or replace the affected harness/connector. Clean any corrosion from connectors using electrical contact cleaner.
   Est. part cost: $20-$500
5. Faulty Wheel Speed Sensor ⚪ Low Probability Wheel speed sensors provide the primary data to the ABS module. If a sensor fails or sends erratic signals (e.g., due to a damaged tone ring or wiring), the ABS module may output invalid data to the rest of the network.
   How to confirm: Use a scan tool to monitor live data from all four wheel speed sensors while driving. A sensor that reads 0 mph or has an erratic signal compared to the others is likely faulty. 🎬 Watch: Finding a hidden ABS wiring problem a dealer might miss. This will usually be accompanied by a specific wheel speed sensor code (e.g., C0031-C003A).
   Typical fix: Replace the faulty wheel speed sensor. The sensor and its wiring are often a single assembly.
   Est. part cost: $50-$150

Rare But Worth Checking

• Vehicle Configuration Mismatch: If major components like the steering angle sensor or other modules have been replaced, the ABS module may need to be re-configured to the vehicle. If this 'proxy alignment' or 're-learn' procedure is skipped, it can send data that other modules deem invalid, triggering U0415.

Diagnosis Steps

1. Check for Recalls: First, check if your vehicle's VIN is part of the August 2024 recall for an ABS software update.
2. Scan for All Codes: Use an advanced OBD-II scanner (like AlfaOBD or wiTECH) to read codes from ALL modules, not just the PCM. Pay close attention to any codes stored in the ABS module itself, especially C2200.
3. Check Battery & Charging System: Verify battery health. A resting voltage should be above 12.4V. With the engine running, check for a stable charging voltage between 13.5V and 14.5V.
4. Inspect Wiring and Connectors: Thoroughly inspect the wiring harness and main connector at the ABS module, which is typically located in the driver's side engine bay or wheel well area. Look for any signs of rodent damage, chafing, or corrosion.
5. Monitor Live Data: If a wheel speed sensor is suspected, use a scan tool to monitor the live data from all four sensors while driving to confirm an erratic or missing signal.
6. Check for Software Updates: If no physical faults are found, the next step is to have a dealer or qualified shop check for available software updates for the ABS module or Hybrid Control Processor (HCP), as specified in TSB 08-037-21.
7. Module Replacement: If all other steps fail, and especially if code C2200 is present, the ABS control module is the likely culprit and will require replacement and programming.

Parts You'll Likely Need

• ABS Control Module

Related Codes That Often Appear With This One

• C2200 — This code specifically indicates an 'Anti-lock Brake Module Internal Electronic Fault' and is a very strong indicator that the ABS module itself has failed and needs replacement.
• P0562 — This code for 'Battery/System Voltage Low' often appears with network codes like U0415 because low voltage can disrupt communication between modules. This was noted in TSB #08-037-21.
• C0051-28 — This code relates to the steering wheel position sensor. Since the stability control system uses both steering angle and wheel speed data, a fault in one system can trigger codes related to the other.
• U0121 — This code for 'Lost Communication With Anti-Lock Brake System (ABS) Control Module' can also be triggered by the same software issues noted in TSB 08-037-21, indicating a severe communication breakdown.

Technical Service Bulletins (TSBs) & Recalls

• TSB 08-037-21: Published March 16, 2021, this TSB applies to 2021 Ram 1500s with the 3.6L eTorque engine. It involves a software update for the Hybrid Control Processor (HCP) to resolve a list of potential DTCs, including U0415-00, P0562 (low battery), and U0121 (lost communication with ABS).
• NHTSA Recall 24V-573 (Unofficial Number, Announced Aug 2024): Stellantis recalled over 1.2 million Ram 1500 trucks (model years 2019, 2021-2024) for a software malfunction in the ABS control module that can disable the Electronic Stability Control (ESC) system, increasing crash risk. The fix is a software update performed by the dealer.

Platform-Specific Known Issues

• NHTSA Complaint ODI #11625519: An owner complaint filed with the NHTSA for a 2021 Ram 1500 specifically mentions retrieving code U0415, which was interpreted as an ABS failure.
• source — A user on Reddit with a 2022 Ram 3500 reported their dashboard 'lit up like a Christmas tree' with multiple service warnings and the only code present was U0415. Other users in the thread confirmed that the ABS controllers on Ram trucks are a known 'terrible' failure point.
• source — An owner of a Ram 1500 experienced a dashboard full of lights (ABS, Traction, Brake) and codes U0415, U0423, and C2200 after hitting a tire on the road. This points to a likely scenario where an impact damaged a wheel speed sensor wire, which in turn caused the ABS module to report invalid data and flag an internal fault.

Mechanic-Grade Diagnostic Values

• CAN Bus Network Resistance — expected: Approximately 60 Ohms between CAN High and CAN Low pins at the OBD-II port (with battery disconnected).. Failure: A reading of 120 Ohms suggests an open circuit or a fault in one of the two terminating resistors (often in the ABS and another module). A reading in the kilo-ohms or mega-ohms at a specific module connector points to an open circuit at that module.
• ABS Module Power Supply Voltage — expected: 12.0V ± 0.5V at the module's power supply pin.. Failure: Low voltage can cause communication dropouts and trigger U-codes.
• ABS Module Ground Resistance — expected: < 5 mΩ (milliohms) between the module's ground pin and a clean chassis ground.. Failure: High resistance indicates a poor ground connection, which is a common cause of intermittent electronic issues.
• Wheel Speed Sensor Wire Resistance — expected: Very low resistance, typically under 1 Ohm, from the sensor connector to the corresponding pins at the ABS module connector.. Failure: High resistance (e.g., kilo-ohms) or an open circuit (OL) indicates a broken wire in the harness.

Hidden / Shadow Codes Worth Checking

• U0415-00: The '-00' suffix is a Failure Type Byte (FTB) or symptom byte. For this code, it generally means 'No Sub Type Information' or that the invalid data is the primary and only fault detail being reported by the module setting the code. It's the most generic form of the U0415 code. (see via Dealer-level scan tools like wiTECH or advanced aftermarket tools like AlfaOBD will display the full DTC with the symptom byte.)

Scan Tool Commands That Help

• wiTECH: ABS Initialization — This function must be run after replacing or reprogramming the ABS module. It performs a self-test and calibrates the system. Failure to run this can leave warning lights on even after a successful repair.
• wiTECH: Restore Vehicle Configuration / PROXI Alignment — Used when a module is replaced to ensure all modules on the network recognize the new part and the vehicle's correct configuration. An incorrect configuration can be a source of invalid data codes.
• AlfaOBD: ABS Initialization — Similar to the wiTECH function, this is used to initialize a newly installed ABS module. It is found under the 'ABS' module selection, in the 'Procedures' tab.
• AlfaOBD / wiTECH: Read/Clear Fault Codes from all modules — Crucial first step to see which other modules are logging faults. U0415 is often set in modules like the PCM or BCM, while the root cause code (like C2200) is stored in the ABS module itself.

Wiring & Ground Locations

• ABS Control Module — In the engine compartment, typically on the driver's side, mounted to the hydraulic control unit. It will have multiple steel brake lines and a large electrical connector attached.. This is the source of the 'invalid data'. The module itself, its connector, and the surrounding harness are primary inspection points for damage or corrosion.
• G101 (Ground) — A primary ground point for the ABS module, located on the left (driver's) side front area of the engine bay, down low.. A loose or corroded G101 ground can cause high resistance in the ABS module's ground circuit, leading to erratic behavior and communication codes like U0415.
• External Power Distribution Center (PDC) — Located in the engine compartment near the battery.. This fuse box contains the main power feeds for the ABS module, typically fuses F06 and F26. A blown fuse or corrosion in the fuse box can cut power to the module.
• ABS Module Connector C3 (at PDC) — A long, black rectangular 42-cavity connector located under the Power Distribution Center (PDC).. Pins 1, 26, and 32 in this connector are related to the ABS module. Corrosion or a poor connection here can interrupt power or communication, causing faults.

Real Owner Repair Stories

• RamForum.com user (2021 Ram 1500) — Dash lit up with ABS, Traction Control, and Brake lights. Received messages for 'Service ABS', 'Service Trailer Brake System', and 'Service Electronic Braking System'.
  ❌ Tried (didn't work) Visual inspection of wiring and connectors showed no obvious damage.
  ✅ What actually fixed it The issue started immediately after hitting a stray tire on the highway with the driver-side wheels. The user suspected wiring damage or a shocked module, with codes U0415, U0423, and C2200 all appearing at once. The combination of codes, especially C2200 (internal module failure), strongly points to the impact either damaging the module internally or compromising its wiring harness, leading to the invalid data fault. The final fix was not posted, but the evidence points to either a wiring repair or ABS module replacement.

OEM Part Supersession History

• 68415317AA → Unknown, but this is a common part number for 2019-2021 Ram 1500 ABS modules. — Part revisions often address hardware or internal logic flaws.
  Heads up: Multiple ABS module part numbers exist for the 2021 model year (e.g., 68415320AA, 68436461AG, 68436462AH) depending on vehicle options like trailer brake control, adaptive cruise, etc. The correct part number must be used, and it must be programmed to the vehicle.