C0020 on 2017-2018 Ram 2500: ABS Pump Motor Failure Causes & Fixes

What's Unique About the 2017-2018 Ram 2500

This is a widely documented problem specific to 2017-2018 Ram 2500 and 3500 trucks, leading to a class-action lawsuit (*Gonzalez v. FCA US LLC*) and an NHTSA investigation (PE22-012). The investigation found that swelling brushes in the ABS pump motor were the core problem. The failure is so common that FCA (Ram's parent company) issued a technical service bulletin (TSB #9004246 / Case #S2005000004) guiding technicians to replace the Hydraulic Control Unit (HCU) separately 🎬 Watch: A complete walkthrough of the HCU replacement process. from the electronic module. This eventually led to a voluntary safety recall (NHTSA Recall No. 24V-896) to replace the defective component. The root cause is poor quality motor brushes that stick in their housings due to carbon dust and tight tolerances, preventing proper electrical contact, especially when hitting bumps.

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 on
• Traction Control (TC) or Electronic Stability Control (ESC) light on
• "Service Electronic Braking System" message on dash
• Cruise control is disabled
• Warning lights may appear intermittently, often triggered by hitting bumps
• In rare cases, an unresponsive or spongy brake pedal
• Audible chime accompanying the warning lights

Most Likely Causes

1. Failed ABS Hydraulic Control Unit (HCU) Pump Motor 🔴 High Probability Multiple owner complaints, an NHTSA investigation, and a class-action lawsuit confirm a widespread manufacturing defect. The carbon brushes inside the pump motor are prone to swelling or getting stuck in their housings with carbon dust, breaking electrical contact with the motor's commutator. This appears to be a supplier quality issue specific to these model years.
   How to confirm: With the vehicle running, lightly tap the round, black ABS pump motor (located inside the driver's side frame rail) with a hammer or screwdriver handle. If the warning lights on the dash flicker or turn on/off, it strongly indicates sticking brushes inside the motor. A professional bidirectional scan tool can also attempt to activate the pump; a failure to run, or an audible buzzing without spinning, confirms the issue.
   Typical fix: The official fix is to replace the entire Hydraulic Control Unit (HCU), which is now covered by a safety recall. A less conventional but popular DIY fix involves removing the pump motor, disassembling it, and cleaning/sanding the sides of the carbon brushes 🎬 See how to perform this $100 DIY motor brush repair. to allow them to move freely. Mail-in repair services are also available.
   Est. part cost: $450-$600 for a new HCU (Mopar P/N 68143491AB).
2. Poor Electrical Connection at ABS Module ⚪ Low Probability
   How to confirm: Disconnect the main electrical connector at the ABS module. Inspect for any signs of corrosion, moisture, or backed-out pins. Wiggling the harness with the vehicle on can sometimes trigger the fault if there's a loose connection. Some owners have had success by disassembling the connector, removing the red front cap, and re-tensioning the female pins with a small tool to ensure a tight fit on the module pins.
   Typical fix: Clean the connector terminals with electrical contact cleaner. If pins are loose, they may need to be re-seated or the connector pigtail replaced.
   Est. part cost: $0-$50
3. Failed ABS Electronic Control Unit (ECU) ⚪ Low Probability
   How to confirm: This is diagnosed by exclusion. If the HCU pump motor and wiring are confirmed to be good, but the code persists, the ECU itself may be at fault. FCA's TSB S2005000004 explicitly instructs technicians to replace the HCU first, and only replace the ECU if the C0020-01 code returns after a test drive.
   Typical fix: Replace the ABS ECU. This part is often sold and replaced as a complete assembly with the HCU, but the TSB advises against this as the initial step.
   Est. part cost: $487+ for the full module assembly (Mopar P/N 68347098AB).

Diagnosis Steps

1. Read fault codes with an OBD-II scanner capable of reading chassis codes to confirm C0020-01 is present.
2. Visually inspect the main electrical harness and connector going to the ABS module for damage, corrosion, or looseness.
3. With the ignition on, access the ABS module located on the driver-side frame rail (may require removing the inner fender liner). Gently tap the round, black ABS pump motor 🎬 Watch: How to diagnose and fix the C0020-01 fault code. with a screwdriver handle. If this causes the warning lights and chime on the dash to appear or disappear, the motor brushes are the confirmed culprit.
4. If available, use a bidirectional scan tool (like AlfaOBD or JScan) to command the ABS pump motor to activate. If it fails to run, this points directly to a faulty motor or its circuit.
5. If the pump does not run, check for power and ground at the ABS module connector according to the vehicle's wiring diagram. An open circuit reading across the two motor leads on the HCU also confirms a motor fault. A simple test is to apply a 9V battery to the two motor contacts; if it doesn't spin, the motor is bad.
6. If power and ground are present and the pump fails the activation test, the Hydraulic Control Unit (HCU) requires replacement or repair.

Parts You'll Likely Need

• ABS Hydraulic Control Unit (HCU) (OEM #68143491AB (replaces 68143491AA)) — This is the component that contains the failure-prone pump motor. Per TSB #9004246 and the subsequent recall, this is the primary replacement part for code C0020-01.
  Trusted brands: Mopar
  OEM price range: $480-$630
  Aftermarket price range: N/A
• ABS Control Module Assembly (OEM #68347098AB) — This is the complete assembly including the electronic (ECU) and hydraulic (HCU) portions. It is often replaced as a unit, though the TSB advises replacing the HCU (68143491AB) first. This part is only needed if the code returns after HCU replacement.
  Trusted brands: Mopar
  OEM price range: $500-$700
  Aftermarket price range: $200-$400 (Remanufactured/Repair Service)

Related Codes That Often Appear With This One

• C2200-49: Anti-lock Brake (ABS) Module Internal Electronic Failure. This code sometimes appears alongside C0020-01, pointing to a fault within the electronic control portion of the ABS assembly.

Technical Service Bulletins (TSBs) & Recalls

• Bulletin #9004246 / Case #S2005000004: Specifies the code C0020-01 as 'ABS PUMP MOTOR CONTROL - GENERAL ELECTRICAL FAILURE' and instructs technicians to replace the HCU first before considering the ECU, as diagnostics were under review. It also noted the part would be on parts restriction.

Platform-Specific Known Issues

• A class-action lawsuit (*Gonzalez v. FCA US LLC*) was filed against FCA, resulting in a settlement and a voluntary safety recall (NHTSA Recall No. 24V-896).
• The NHTSA opened an official investigation (PE22-012) into the problem in December 2022, which identified swelling motor brushes as the root cause.
• Owner complaints frequently mention that the replacement parts are on national backorder, with waits lasting months. Some dealers were reportedly rationing parts, only able to order one per week.
• The failure is known to be recurrent; some owners have had the module replaced under warranty only for the new part to fail again in as little as 15,000-20,000 miles.

Mechanic-Grade Diagnostic Values

• ABS Pump Motor Fuse Resistance — expected: 0 ohms. Failure: An open circuit (infinite resistance) reading indicates a blown fuse.
• Voltage at ABS Pump Motor Fuse — expected: ~12.6V with ignition on, ~13.5V with engine running. Failure: A significant voltage drop below battery voltage indicates a problem in the power supply wiring to the fuse block.

Hidden / Shadow Codes Worth Checking

• C0020-16: ABS Pump Motor Control - Circuit Voltage Below Threshold. This indicates the voltage supplied to the pump motor is too low (e.g., 50% of ignition voltage). (see via Professional scan tools like wiTECH or advanced DIY tools like AlfaOBD can read these manufacturer-specific suffix codes.)
• C0020-1C: ABS Pump Motor Control - Circuit Voltage Out of Range. This can be set by a poor ground connection for the pump motor or an internal short in the ABS module's motor driver. (see via Professional scan tools like wiTECH or advanced DIY tools like AlfaOBD can read these manufacturer-specific suffix codes.)

Scan Tool Commands That Help

• AlfaOBD / JScan / wiTECH: ABS Pump Motor Activation / Actuation Test — This is a key diagnostic step. Use this command to attempt to run the pump motor. If the motor does not run, it confirms a fault in the motor or its power/ground circuit, which is the core of the C0020-01 issue.
• AlfaOBD / JScan / wiTECH: ABS Bleed Procedure / ABS Initialization — This is a mandatory step after replacing the Hydraulic Control Unit (HCU). The procedure cycles the pump and internal solenoids to purge all air from the new component, which cannot be done with a manual bleed alone.
• wiTECH: Restore Vehicle Configuration / ABS Initialization — If a used ABS module is installed, its VIN will not match the vehicle's, causing a 'VIN Mismatch' fault. The wiTECH service tool has a function to program the vehicle's VIN into the replacement module and initialize it.

Wiring & Ground Locations

• ABS Module Connector — On the ABS module, located on the driver's side frame rail, accessible after removing the inner fender liner.. This is the main electrical interface for the entire ABS system. Corrosion or loose pins in this large connector can cause the C0020 code. Wiggling the connector while the system is on can help diagnose a poor connection.
• ABS Pump Motor Fuse — In the under-hood fuse box (Power Distribution Center). It is a high-amperage fuse, typically 40A.. This fuse provides the high current required to run the ABS pump motor. While not a common failure point for this specific issue, it is a fundamental check for any 'no power' condition to the pump.

Real Owner Repair Stories

• YouTube user 'cheeesman1' (2017 Ram 5500, 58,000 miles) — ABS and traction control lights flashing on and off when hitting bumps, cruise control disabled, code C0020-01 present.
  ❌ Tried (didn't work) The HCU/ABS module had been replaced by the dealer at 20,000 miles, but the problem returned by 38,000 miles.
  ✅ What actually fixed it The owner removed the ABS pump motor from the HCU (without disconnecting brake lines), disassembled the motor housing, and found one of the two carbon brushes was stuck in its guide and not making contact with the commutator. He freed the stuck brush, cleaned the carbon dust, reassembled the motor, and the problem was resolved.
• YouTube user 'MKS Performance & Offroad' (2017-2018 Ram 2500/3500) — Intermittent 'Service ABS System' warning on the dash.
  ✅ What actually fixed it The video demonstrates two successful fixes. The first is replacing the entire HCU. The second, more detailed fix, involves disassembling the pump motor, finding the brushes are too tight in their guides, and replacing them with new 6x6x15mm carbon brushes ordered from Amazon that are then sanded down to fit properly.

OEM Part Supersession History

• 68143491AA → 68143491AB — The 'AA' revision is the original, failure-prone part. The 'AB' revision is the updated replacement intended to resolve the sticking brush issue.
  Heads up: Both parts are physically interchangeable, but installing another 'AA' revision part is likely to result in a repeat failure.