C0033 on 2015-2016 Ram 1500: Right Front Tone Wheel Failure Causes & Fixes

What's Unique About the 2015-2016 Ram 1500

On this generation of Ram 1500 (and its platform mates), the tone wheel is not a separate, serviceable part like the toothed rings on older vehicles. Instead, it is a magnetic encoder ring integrated into the seal of the wheel hub and bearing assembly. This design means that a failure of the tone wheel, whether from damage, delamination, or a worn-out wheel bearing causing excessive play, requires the replacement of the entire hub assembly. This is a common point of failure and a frequent topic in owner forums, especially in regions with high road salt usage, which can cause the hub to seize to the aluminum steering knuckle, 🎬 Watch this step-by-step guide to replacing the front wheel hub assembly. complicating the repair.

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 is on
• Traction Control (ESC) warning light is on
• "Service ABS System" or similar message on the dash
• Cruise control may be disabled
• 4WD system may show a service light or be disabled (if equipped).
• Brake pedal may vibrate or pulsate at low speeds as the ABS system incorrectly activates.
• A roaring, grinding, or clicking noise from the front wheel area, indicative of a failing wheel bearing.
🎬 Watch: 6 common causes for an ABS light and how to fix them.

Most Likely Causes

1. Failed Wheel Hub and Bearing Assembly 🔴 High Probability → Shop Hub Assembly The tone wheel is integrated into the hub assembly's seal. Wear and tear on the bearing can cause excessive play (wobble), which damages the magnetic tone ring or creates an incorrect air gap with the sensor, leading to signal loss. The magnetic ring itself can also crack or delaminate from corrosion.
   How to confirm: Safely jack up the front right wheel and check for any play or wobble by grabbing the tire at the 12 and 6 o'clock positions. Any noticeable movement indicates a bad bearing. A roaring or grinding sound while spinning the wheel is another confirmation. A scan tool showing an erratic or dropping signal from the right front wheel, when compared to the others, points to this failure.
   Typical fix: Replace the entire right front wheel hub and bearing assembly. In rust-prone areas, the hub can seize to the aluminum knuckle, requiring a specialized puller or the use of the vehicle's own power steering to press it out.
   Est. part cost: $150-$400
2. Damaged or Corroded Wiring/Connector 🟡 Medium Probability The wheel speed sensor wiring harness is exposed to road debris, moisture, and salt, which can lead to corrosion in the connector pins or physical damage (chafing, breaks) to the wires. This is a known issue, and forum users frequently advise checking the wiring first.
   How to confirm: Visually inspect the wiring harness leading from the right front wheel speed sensor up into the fender well. Unplug the connector and check for green or white corrosion, or bent/broken pins. A multimeter can be used to check for voltage and continuity at the connector.
   Typical fix: Clean the connector terminals with a specialized contact cleaner. If the wiring is damaged, it's highly recommended to replace the entire sensor/harness assembly rather than attempting a splice, as repairs can introduce resistance and cause future signal issues.
   Est. part cost: $10-$100
3. Faulty Right Front Wheel Speed Sensor ⚪ Low Probability → Shop ABS Wheel Speed Sensor While the sensor itself can fail, it's less common than a hub failure for this specific code. Corrosion can build up under the sensor's mounting point, physically pushing it away from the tone ring and increasing the air gap, which causes a weak or lost signal.
   How to confirm: The best way is to use a scan tool that can read live ABS data. Watch the signal from the right front sensor while driving; if it drops out or is erratic compared to the others, and the hub/wiring are good, the sensor is likely faulty. You can also swap the right and left front sensors to see if the code follows the sensor.
   Typical fix: Replace the right front wheel speed sensor. It is critical to thoroughly clean the mounting surface on the knuckle before installing the new sensor to ensure the correct air gap.
   Est. part cost: $35-$75

Rare But Worth Checking

• Failed ABS Control Module: → Shop ABS Control Module This is very rare. Before condemning the expensive ABS module, all other possibilities (hub, sensor, wiring) must be exhaustively ruled out by a professional. A code like C2200 is more indicative of a module failure.

Diagnosis Steps

1. Confirm the code with an ABS-capable OBD-II scanner. Note any other related codes like C0034.
2. Use the scanner to monitor live data from all four wheel speed sensors while driving. Observe if the right front sensor's reading is erratic, drops to zero, or doesn't match the other wheels.
3. Safely raise and support the front of the vehicle. Grasp the right front tire at the top and bottom (12 and 6 o'clock) and attempt to rock it. Any significant play or clunking points to a failed wheel bearing.
4. Spin the right front wheel by hand and listen for any grinding or roughness, which also indicates a bad bearing.
5. Visually inspect the wheel speed sensor wiring and connector for any signs of damage, chafing, or corrosion. Trace the wire from the hub into the fender well.
6. If no bearing play is found but the signal is bad, inspect the sensor. Remove the 5mm hex bolt, pull the sensor, and check its tip for metallic debris. Clean the mounting surface on the knuckle thoroughly before reinstalling or replacing.
7. If wiring and sensor are confirmed good, and bearing play is present or the signal is still bad, the failure is inside the hub assembly. The entire wheel hub and bearing assembly must be replaced.

Parts You'll Likely Need

• Front Wheel Hub and Bearing Assembly (OEM #68453985AD (supercedes 68453985AC)) — This is the most common cause of code C0033 because the magnetic tone wheel is integrated into this assembly. A worn bearing or damaged magnetic ring necessitates replacing the entire unit.
  Trusted brands: Mopar, MOOG, Timken, SKF, DuraGo
  OEM price range: $220-$320
  Aftermarket price range: $150-$250
• Front Wheel Speed Sensor — Replaced if the sensor itself is faulty or if the wiring harness is damaged, as it is often sold as a single unit. Less common fix than the hub itself.
  Trusted brands: Mopar, Standard Motor Products, Delphi, TRQ
  OEM price range: $50-$80
  Aftermarket price range: $30-$60

Related Codes That Often Appear With This One

• C0034 — C0034 points to the Right Front Wheel Speed Sensor circuit. The two codes often appear together because a problem with the hub/tone wheel (C0033) can cause the sensor to generate an erratic signal that the ABS module interprets as a sensor fault (C0034).

Technical Service Bulletins (TSBs) & Recalls

• 68292756A$: Confirms the code definition as 'Right Front Tone Wheel-General Signal Failure' for 2016 Ram trucks.
🎬 See a real-world diagnosis of the C0033-02 code on a Ram EcoDiesel.

Platform-Specific Known Issues

• The provided NHTSA Technical Service Bulletin #68292756A$ lists C0033-02 (Right Front Tone Wheel-General Signal Failure) as a potential fault code for the 2016 Ram, confirming the definition and its relevance to this specific vehicle.
• A significant issue during repair is the hub assembly corroding and seizing to the aluminum steering knuckle, particularly in the rust belt. This can make removal extremely difficult, sometimes requiring specialized tools or even damaging the knuckle.
• TSB 08-044-16 for 2016 models addresses an issue where the instrument cluster illuminates on its own, which involves an RF Hub Module software flash, but is unrelated to this ABS code.

Mechanic-Grade Diagnostic Values

• Wheel Speed Sensor Signal (Hall-Effect Type) — expected: On this vehicle, the sensor is a two-wire Hall-effect type. The ABS module provides a 12V reference, and the sensor varies this voltage, producing a digital square wave signal as the wheel turns. The signal is superimposed on the power wire.. Failure: Using a scan tool, the signal from the right front wheel will drop out, become erratic, or read significantly different from the other three wheels while driving. For example, reading 62 km/h when other wheels are at 78 km/h, or dropping to zero when coming to a stop below 16 km/h.

Hidden / Shadow Codes Worth Checking

• C0033-02: Right Front Tone Wheel - General Signal Failure. This is the manufacturer-specific sub-code that pinpoints the tone wheel signal as the problem. (see via Professional scan tools like Mopar's wiTECH or advanced aftermarket scanners (e.g., AlfaOBD) can read these sub-codes.)

Scan Tool Commands That Help

• wiTECH or AlfaOBD: ABS Initialization — This procedure is required after replacing the ABS control module to ensure it is properly configured to the vehicle. It may also be used during diagnostics to reset the system after other repairs.
• wiTECH or AlfaOBD: Read/Clear Faults — Used to verify if the C0033 code is active and to clear it after a repair is performed. The code must be active for some diagnostic tests to be valid.
• Advanced Scan Tool (Live Data): Graph All WSS Speeds — This is the primary diagnostic step. By graphing all four wheel speed sensors simultaneously while driving, a technician can visually confirm if the right front sensor's signal is dropping out or behaving erratically compared to the others.

Wiring & Ground Locations

• ABS Module Fuses — In the main underhood fuse box (Power Distribution Center) next to the battery.. Before complex diagnostics, it's wise to check F6 (40A ABS Pump), F26 (30A ABS Valves), and F76 (10A ABS/ESC Module) to rule out a simple power supply issue.
• ABS Control Module — Located in the driver's side front wheel well, behind the fender liner. It is attached to the hydraulic pump assembly.. This is the computer that receives the signal from the wheel speed sensor and sets code C0033. The main wiring harness connects here, and it's a potential point for connection issues, though module failure itself is rare for this specific code.

Real Owner Repair Stories

• Screamin' Diesel Ltd. on YouTube (2016 Ram 1500 EcoDiesel) — ABS and traction control lights on. Brake pedal would vibrate/pulsate when coming to a stop at low speeds. Scan tool showed code C0033-02.
  ❌ Tried (didn't work) The technician immediately suspected a bearing or sensor issue based on the code and symptoms.
  ✅ What actually fixed it The technician jacked up the truck and found excessive play in the right front wheel, indicating a failed wheel bearing. Replacing the entire right front wheel hub and bearing assembly resolved the issue. The post-repair scan tool data showed a smooth, consistent signal from the new sensor.

OEM Part Supersession History

• 68453985AC → 68453985AD — Standard part revision by the manufacturer.
  Heads up: The new part number (68453985AD) is the correct replacement for the original and is fully compatible.