C0050 on 2014-2023 Ram ProMaster: Right Rear Wheel Speed Sensor Circuit Fault, Causes, and Fixes

What's Unique About the 2014-2023 Ram ProMaster

The Ram ProMaster, based on the Fiat Ducato, has been in its current generation since its North American debut in 2014, so the diagnosis for this code is consistent across the 2014-2023 year range. A key point for this van is that while the wheel speed sensor is a separate, replaceable part, the magnetic encoder ring it reads is integrated into the rear wheel hub and bearing assembly. This means that if the ring is damaged or corroded, the entire hub assembly must be replaced, even if the sensor itself is functional. This integrated design is a common failure point, as confirmed by owners of its platform-mate, the Fiat Ducato, who report replacing the sensor only to find the hub's magnetic ring was the true culprit.

Symptoms You May Notice

• ABS warning light is on
• Electronic Stability Control (ESC) or traction control warning light is on
• "Service ESC System" or similar message on the dashboard
• "Service Hill Start Assist" message on the dash 🎬 Watch: Common causes and solutions for ESC and Hill Holder issues.board
• Cruise control is disabled
• Wheels may lock up and skid during hard braking

Most Likely Causes

1. Failed Right Rear Wheel Speed Sensor 🔴 High Probability → Shop ABS Wheel Speed Sensor The sensor is exposed to road debris, water, and salt, leading to corrosion and electronic failure over time. It's the most frequently replaced part for this code.
   How to confirm: Use an ABS-capable scan tool to monitor live data from all four wheel speed sensors while driving. If the right rear sensor shows 0 MPH or an erratic reading while the others read correctly, the sensor is likely bad. You can also test the sensor's internal resistance with a multimeter; a good sensor should have a specific resistance value (e.g., some Ram sensors test around 1000-2300 ohms), while a bad one may show an open circuit (infinite resistance). Swapping it with the left side sensor (if they are the same part number) to see if the code changes to C0045 (left rear) is another effective diagnostic step.
   Typical fix: Replace the right rear wheel speed sensor. The sensor is typically held in by a single bolt and is accessible after removing the wheel.
   Est. part cost: $30-$75
2. Damaged Wiring or Connector 🟡 Medium Probability The wiring harness runs along the chassis and suspension to the wheel hub, making it vulnerable to damage from road debris, improper jacking, or corrosion, especially at the connector. Rodent damage is also a known issue on these vans.
   How to confirm: Visually inspect the entire length of the wiring harness from the wheel hub back to the main chassis. Look for any cuts, abrasions, melting, or signs of rodent damage. Unplug the connector at the sensor and check for green or white corrosion on the pins. Perform a continuity test on the wires between the sensor connector and the ABS module connector to check for opens or shorts to ground.
   Typical fix: Repair the damaged section of wire with solder and heat-shrink tubing or replace the pigtail connector if it is corroded. Secure the harness away from moving parts.
   Est. part cost: $15-$40
3. Damaged or Contaminated Wheel Hub Encoder Ring 🟡 Medium Probability The magnetic encoder ring is built into the seal of the rear wheel hub assembly. Rust jacking under the ring or metallic debris from brake wear can accumulate on it, disrupting the signal the sensor reads. This is a very common misdiagnosis, where the sensor is replaced but the hub is the actual problem.
   How to confirm: After removing the wheel speed sensor, use a flashlight and a small mirror to inspect the magnetic ring on the hub assembly. Spin the hub and look for cracks, rust buildup, or metallic debris stuck to the surface. A damaged or severely corroded ring will provide an erratic signal.
   Typical fix: The encoder ring is not serviced separately. The entire rear wheel hub and bearing assembly must be replaced.
   Est. part cost: $190-$400

Rare But Worth Checking

• Loose ABS Module Ground: → Shop ABS Control Module A recall (NHTSA 24V-290) was issued for some 2021 ProMaster models (built Aug 14, 2021 - Oct 18, 2021) due to a loose ground nut (Part #06107185AA) for the ABS module. This was an assembly error, not a part defect. This can cause loss of communication, various ABS codes, and system failure. While specific to 2021, it's a quick and valuable check for any year: ensure the main ground connection for the ABS module is clean and tight.
• Failed ABS Control Module: → Shop ABS Control Module This is the least likely cause. The ABS module is the computer for the brake system. It typically fails only after all other possibilities (sensor, wiring, hub) have been eliminated. A module failure will often set additional communication codes (like U0121) or internal fault codes.
• Post-Repair Hydraulic Leak: While documented on other heavy-duty Ram platforms, TSB Bulletin #S2505000003 notes that DTC C0050-00 can sometimes be set following a recent repair if a brake system hydraulic leak occurs.

Diagnosis Steps

1. Connect an ABS-capable scan tool and confirm the presence of code C0050. 🎬 See this walkthrough on diagnosing and fixing the C0050 code. Note any other codes or manufacturer-specific sub-codes (e.g., C0050-5A for 'Signal not plausible').
2. View live data from all four wheel speed sensors. Drive the vehicle slowly (above 5 MPH) in a straight line. Compare the Right Rear (RR) speed reading to the others. A reading of zero or one that is erratic or jumps around points to a fault in the RR circuit.
3. Raise and safely support the rear of the vehicle. Remove the right rear wheel.
4. Visually inspect the wheel speed sensor and its wiring harness for obvious damage, corrosion, or loose connections. Pay close attention to where the harness may rub against suspension or chassis components.
5. Unplug the sensor. Inspect the connector pins for corrosion or damage. Clean with electrical contact cleaner if necessary.
6. Remove the single bolt holding the wheel speed sensor and carefully pull it out of the hub. It may be seized and require gentle prying.
7. Inspect the magnetic encoder ring on the wheel hub assembly through the sensor mounting hole. Look for cracks, heavy rust, or metallic debris. Clean any debris and re-test. If the ring is cracked or damaged, the hub assembly needs replacement.
8. If the ring looks good, test the sensor. You can measure its resistance with a multimeter (if specifications are known) or swap it with the left rear sensor to see if the fault code follows (changes to C0045). A bad sensor often shows an open circuit.
9. If the sensor and hub appear good, perform a continuity test on the wiring harness between the sensor connector and the ABS control module to check for opens or shorts. Wiggle the harness during the test to find intermittent faults.
10. Check the ABS module ground connection to ensure it is clean and tight, as highlighted by recall 24V-290 for 2021 models.
11. If wiring, sensor, and hub are all confirmed to be good, the final step is to diagnose the ABS control module itself, which is best left to a professional.

Parts You'll Likely Need

• Rear Wheel Speed Sensor (OEM #68199238AB) — This is the most common failure point. The sensor is exposed to the elements and can fail electronically over time. Part number 68199238AB is listed for both left and right rear positions on many ProMaster models.
  Trusted brands: Mopar, Standard Motor Products (SMP), Dorman, Holstein
  OEM price range: $50-$80
  Aftermarket price range: $30-$60
• Rear Wheel Hub & Bearing Assembly (OEM #68094829AB) — Required if the integrated magnetic encoder ring is damaged, cracked, or separated due to rust. The ring is not sold separately. The OEM part number 68094829AB is listed for the rear hub.
  Trusted brands: Mopar, Timken, MOOG, SKF
  OEM price range: $400-$590
  Aftermarket price range: $190-$350

Related Codes That Often Appear With This One

• C0037 — This code is for the Left Rear Wheel Speed Sensor. If both appear, it could suggest a shared wiring problem or similar wear/damage to both rear hub assemblies. A Reddit user with a 2023 ProMaster reported C0037 along with several related codes, all pointing back to the wheel speed sensor circuit.
• U0415 — Invalid Data Received From Anti-Lock Brake System Control Module. This code is often set in other modules (like the PCM or BCM) when the ABS module reports a fault and goes offline.

Technical Service Bulletins (TSBs) & Recalls

• NHTSA 24V-290: A voluntary safety recall for 2021 Ram ProMaster models built between August 14, 2021, and October 18, 2021. An improperly tightened ground nut for the ABS module could lead to a loss of communication and failure of the ESC system. The remedy is to inspect and tighten the nut to the proper specification.
• TSB Bulletin #S2505000003: A manufacturer service bulletin notes that DTC C0050-00 can be set in the brake system if a hydraulic leak occurs after a recent repair.

Mechanic-Grade Diagnostic Values

• Wheel Speed Sensor Signal Voltage (at sensor connector) — expected: A toggling DC voltage, typically between ~0.7V and ~1.4V, when spinning the wheel by hand. This indicates the sensor is generating a signal.. Failure: A steady voltage or 0V indicates a dead sensor or a wiring issue.
• Sensor Supply Voltage (at harness connector, key on) — expected: Should be less than 1V between the 12V reference circuit terminal and ground.. Failure: A reading greater than 1V could indicate a short to voltage in the reference circuit.

Hidden / Shadow Codes Worth Checking

• C0050-5A: Signal Plausibility Failure. The signal from the sensor is present but doesn't make sense compared to other vehicle speed inputs. This often points to a damaged magnetic encoder ring or an intermittent wiring fault. (see via Professional scan tools like Mopar wiTECH or high-end Autel/Snap-on scanners that can read manufacturer-specific symptom bytes.)
• C0050-18: Low Signal Amplitude. The signal from the sensor is too weak. This can be caused by an excessive air gap between the sensor and ring, heavy debris, or a failing sensor. (see via Professional scan tools like Mopar wiTECH or high-end Autel/Snap-on scanners.)
• C0050-0F: Erratic Signal. The sensor signal is inconsistent or drops out. This strongly suggests a mechanical issue like a cracked encoder ring, debris, or a loose connection. (see via Professional scan tools like Mopar wiTECH or high-end Autel/Snap-on scanners.)
• C0050-06: Low Voltage / Open Circuit. This indicates a likely open in the wiring, a bad sensor, or a fault within the ABS module's power supply to the sensor. (see via Professional scan tools like Mopar wiTECH or high-end Autel/Snap-on scanners.)

Scan Tool Commands That Help

• wiTECH, AlfaOBD, Autel: Live Data > ABS Module > Wheel Speed Sensors — This is the primary diagnostic step. It allows the technician to view and graph the speed signal from all four wheels in real-time while driving. A faulty right rear sensor will show a flat line, erratic signal, or a reading that doesn't match the others.
• wiTECH, AlfaOBD: Proxy Alignment — This procedure is mandatory if the ABS control module itself is replaced. It synchronizes the new module with the vehicle's other computers. Failure to perform a proxy alignment will result in a flashing odometer and non-functional ABS/ESC systems.

Wiring & Ground Locations

• ABS Control Module (HCU) — Located in the engine bay on the driver's side, mounted below the master cylinder and brake booster.. This is the destination for the wheel speed sensor wiring. The main connector here is a critical point for testing continuity back to the sensor.
• ABS Module Ground — A ground wire runs from the ABS wiring harness to a stud on the chassis, typically very close to the module itself in the driver's side engine bay. For 2021 models, a specific recall (24V-290) addressed a loose ground nut at this location.. A poor ground for the ABS module can cause a wide range of erratic codes, including false wheel speed sensor faults, and loss of communication.
• Right Rear WSS Circuit at ABS Connector — A YouTube video for a similar year Ram truck identifies the two rearmost pairs of wires on the bottom row of the large ABS module connector as being for the rear wheel speed sensors. The Orange/Green pair corresponds to the right rear sensor.. Knowing these specific wire locations allows for targeted continuity and voltage testing directly at the module, confirming if the fault is in the wiring harness or elsewhere.

Real Owner Repair Stories

• promasterforum.com user (2016 Ram ProMaster) — ABS and ESC warning lights on, code C0050 present.
  ❌ Tried (didn't work) Replaced the right rear wheel speed sensor.
  ✅ What actually fixed it The code returned after replacing the sensor. The final fix was replacing the entire right rear wheel hub and bearing assembly. The magnetic encoder ring on the original hub was found to be damaged/corroded, which was the true source of the bad signal.
• promasterforum.com user (2017 Ram ProMaster 2500) — ABS, traction control, and hill assist warning lights on.
  ❌ Tried (didn't work) Initial diagnosis pointed to the sensor.
  ✅ What actually fixed it The wiring harness for the wheel speed sensor had chafed through where it passed near the leaf spring mounting bracket. Repairing the damaged wires resolved the code.

OEM Part Supersession History

• 68094829AA → 68094829AB — Standard part revision/update by the manufacturer.
  Heads up: Parts are interchangeable. The 'AB' revision is the current and correct replacement part.
• Unknown (possibly 68199238AA) → 68199238AB — Standard part revision/update by the manufacturer.
  Heads up: Parts are interchangeable. 68199238AB is the current OEM part number for the rear sensor.

Model Year Variations Within This Range

• 2022-2023: The 2022 model year introduced a significant refresh with a new 9-speed transmission, an electric power steering system, and an electric parking brake. While the fundamental wheel speed sensor and hub design remained the same, the ABS module is more deeply integrated with new systems like Lane Keep Assist and Adaptive Cruise Control. A fault in the WSS circuit will disable a larger number of driver-assist features on these later models.

Diagnostic Flowchart

Used vs. New Parts: Buying Guide for This Vehicle

When a used part is the smart pick: A used OEM wheel hub assembly from a low-mileage donor vehicle can be a cost-effective alternative to a new OEM part, which can be expensive. This is a good option if the magnetic ring on your original hub is confirmed to be the problem.

Donor-vehicle mileage cap: roughly under 60000 miles for the part to have meaningful remaining life.

What to inspect on the donor part:

• Verify the donor vehicle's mileage.
• Inspect the magnetic encoder ring on the used hub for any visible cracks, rust, or damage before purchase.
• Source the part from a dry, non-salt-belt state to minimize the risk of corrosion and bearing wear.
• Ensure the bearing spins smoothly by hand with no roughness or play.

OEM-only on this vehicle (don't cheap out):

• ABS Control Module - While not a common fix for this code, if needed, a new or remanufactured OEM module is recommended due to the critical need for correct software and the requirement for Proxy Alignment programming.

Aftermarket brands forum-validated for this vehicle:

• For Wheel Hubs: Timken, MOOG, SKF are reputable brands known for quality bearings.
• For Sensors: Standard Motor Products (SMP), Dorman, and Holstein are reliable aftermarket choices.

Brands owners have reported issues with on this vehicle:

• Ultra-low-cost, unbranded wheel hubs and sensors from online marketplaces often have high failure rates and poor-quality bearings or magnetic rings, leading to a repeat repair.

Real Owner Stories

Aggregated from forums and TSBs cited above. Mileages and costs reflect what owners reported in those sources.

Related OBD-II Codes

• C0045 — This is the code for the Left Rear Wheel Speed Sensor circuit. It is directly related as a diagnostic companion; swapping the right rear sensor (C0050) with the left rear sensor is a key test. If the code changes to C0045, the sensor itself is confirmed to be faulty.
• C0036 — A code for the Left Rear Wheel Speed Sensor circuit. An owner report confirmed that this code produces the identical set of dashboard warnings (Service ABS, ESC, Hill Start Assist) as C0050, indicating the same failure mode on a different wheel.
• C0037 — Another code related to the Left Rear Wheel Speed Sensor circuit. It often appears with C0036 and points to the same type of fault as C0050, just on the opposite side of the vehicle.
• C0050-5A — This is a manufacturer-specific sub-code or 'symptom byte' for C0050. The '-5A' provides more detail, indicating 'Signal not plausible,' which helps a technician differentiate between a complete signal loss and an erratic or unbelievable signal from the sensor.

Frequently Asked Questions