C0020 on 2020-2021 Ford Explorer: ABS Pump Motor Fault Causes and Fixes

What's Unique About the 2020-2021 Ford EXPLORER

On the 2020-2021 Ford Explorer (and related Lincoln Aviator and Police Interceptor Utility), the appearance of code C0020 is very frequently a red herring. Ford identified a specific manufacturing issue where a poor ground connection at location G108 (on the driver's side front frame rail) or improper plating on the ground bolts causes the code to set, mimicking a catastrophic failure of the expensive ABS module. This led to the release of TSB 21-2030, which advises technicians to correct the ground issue before considering replacing the ABS module/HCU.

Diagnostic Flowchart

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

Symptoms You May Notice

• Illuminated Anti-lock Brake System (ABS) warning light
• Illuminated Traction Control or Stability Control light
• Pre-Collision Assist Not Available warning message
• AWD system warnings or faults
• Loss of ABS function (wheels may lock up during hard braking)
• Loss of traction and stability control function

Most Likely Causes

1. Poor Ground Connection at G108 🔴 High Probability A known manufacturing issue documented in Ford TSB 21-2030 affects vehicles built on or before December 24, 2020. The bulletin points to a poor ground connection or improper plating on the attachment bolts at this specific ground point.
   How to confirm: Inspect the ground connection at location G108 🎬 Watch: How to properly inspect and clean engine ground connections., which is on the driver's side frame rail in the front wheel well area. Check for looseness or corrosion. The TSB provides a specific service procedure for technicians to follow.
   Typical fix: Follow the procedure in TSB 21-2030: remove the ground fasteners, clean the contact surfaces of the frame and the cable eyelets, and install new, properly plated fasteners (Ford Part No. W718919-S439). This often resolves the code without any parts replacement.
   Est. part cost: $5-$20
2. Faulty ABS Module / Hydraulic Control Unit (HCU) ⚪ Low Probability → Shop ABS Control Module While this is the component the code points to, it's often not the actual cause on this specific vehicle due to the known TSB. However, an internal failure of the pump motor or the module's electronics can still occur, especially on vehicles not covered by the TSB's build dates.
   How to confirm: This should only be considered after the ground issue (TSB 21-2030) has been ruled out. A technician would use a high-level scan tool to command the ABS pump motor to activate. If the pump doesn't run despite having good power and a verified ground, the module/HCU assembly is likely faulty.
   Typical fix: Replacement of the ABS module and Hydraulic Control Unit (HCU) assembly, followed by programming and brake system bleeding.
   Est. part cost: $700-$1500

Rare But Worth Checking

• Wiring Harness or Connector Issue: Corrosion or damage to the wiring or connector pins leading to the ABS module can cause an open or shorted circuit, triggering the C0020 code.
• Low Battery Voltage: → Shop Vehicle Battery A weak or aging battery or a failing alternator 🎬 Watch: Step-by-step guide for replacing the battery on this platform. can provide insufficient voltage to the ABS module, which can set this code, especially during the self-test at startup. Forum users have reported that low voltage during startup can trigger various electrical faults.
• ABS Control Module Software Glitch: → Shop ABS Control Module Outdated or corrupted software within the ABS module can sometimes misinterpret normal motor function and falsely trigger a C0020 code. A dealer or qualified shop can check for available software updates.

Diagnosis Steps

1. Check for Technical Service Bulletins (TSBs). Specifically, check if TSB 21-2030 applies to your vehicle's build date (on or before Dec 24, 2020).
2. If the TSB applies, perform the service procedure. Locate ground G108 on the driver's side front frame rail. Disconnect the battery, remove the ground nuts/bolts, thoroughly clean the cable eyelets and the frame surface to bare metal, and install new fasteners.
3. Clear the DTCs and perform a road test to see if the code returns.
4. If the TSB does not apply or the fix does not work, inspect the main ABS module electrical connector (C135) for corrosion, moisture, or pushed-out pins.
5. Using a multimeter, verify that the ABS module is receiving proper battery voltage and has a solid ground connection. Check for battery voltage at Pin 1 (VT/RD wire) and Pin 25 (BU/RD wire) of connector C135. Check for ground by measuring resistance between Pin 13 (BK/YE wire) and Pin 38 (BK/YE wire) of C135 and a clean chassis ground; it should be less than 5 ohms.
6. Using a professional scan tool (like FORScan or Ford IDS), attempt to command the ABS pump motor to activate (PMP_MOTOR). Listen for the motor running.
7. If the motor does not run but power and ground are confirmed to be good, the ABS module/HCU assembly has likely failed and requires replacement.

Parts You'll Likely Need

• Ground Cable Fasteners (OEM #W718919-S439) — Per TSB 21-2030, the original bolts may have improper plating. The TSB procedure involves replacing them with new, properly plated ones to ensure a good ground connection.
  Trusted brands: Motorcraft
  OEM price range: $5-$20
  Aftermarket price range: $5-$15
• ABS Control Module / HCU Assembly (OEM #LC5Z-2C219-D (Note: Part number can vary based on vehicle options like AWD/FWD and specific calibration. Always verify with VIN.)) — This is the part to replace ONLY if the ground issue is ruled out and the module is confirmed to be faulty through diagnostic testing.
  Trusted brands: Motorcraft, Bosch (OEM supplier)
  OEM price range: $700-$1500
  Aftermarket price range: $400-$900

Related Codes That Often Appear With This One

• U0418 - Invalid Data Received From Brake System Control Module 'A'
• U0102 - Lost Communication With Transfer Case Control Module

Technical Service Bulletins (TSBs) & Recalls

• TSB 21-2030: Addresses an illuminated ABS lamp with DTC C0020 due to a poor ground connection at G108. This bulletin supersedes previous versions.
• TSB 21-2017: An earlier version of the bulletin for the same C0020 ground issue, later superseded by TSB 21-2030 to update the production fix date.
• TSB 20-2364: The original bulletin for the C0020 ground issue, also superseded.

Platform-Specific Known Issues

• TSB 21-2030: The Definitive Fix: Ford explicitly states that for 2020-2021 Explorer/Aviator/Police Interceptor Utility models built on or before December 24, 2020, DTC C0020 is likely caused by a poor ground connection at G108 and that replacing the ABS module is likely unnecessary. The fix involves cleaning the ground surfaces and replacing the fasteners.
• Owner Experience: Successful Ground Repair: An owner on explorerforum.com with a 2020 Explorer XLT experiencing ABS and Pre-Collision Assist warnings confirmed the dealer performed TSB 21-2030. The repair involved cleaning the G108 ground and replacing the nut, which successfully resolved all warning lights and codes.

Mechanic-Grade Diagnostic Values

• ABS Module Ground Circuit Resistance — expected: Less than 5.0 Ω. Failure: Resistance greater than 5.0 Ω indicates a poor ground connection at G108 or elsewhere in the circuit.
• ABS Module Power Supply Voltage (at Connector C135, Pin 1) — expected: Greater than 10-12 Volts. Failure: Voltage below this range indicates a problem with the power supply from the Battery Junction Box, fuse, or wiring.
• ABS Pump Motor Voltage Feedback (Internal Test) — expected: Less than 0.75 volts for less than 50 milliseconds. Failure: Voltage greater than 0.75V for more than 50ms sets a C0020:15 suffix code, indicating an open or short in the motor circuit.

Hidden / Shadow Codes Worth Checking

• C0020:16: ABS Pump Motor Control: Circuit Voltage Below Threshold. This indicates the ABS module detected an undervoltage condition at the pump motor's power input, reinforcing the possibility of a bad ground or power supply issue. (see via Ford-specific scan tools like IDS, FDRS, or advanced tools like FORScan.)
• C0020:49: ABS Pump Motor Control: Internal Electronic Failure. This sets when the pump's actual state (running or not) does not match the commanded state. (see via Ford-specific scan tools like IDS, FDRS, or advanced tools like FORScan.)
• C0020:71: ABS Pump Motor Control: Actuator Stuck. This sets when the ABS module commands the pump motor to run, but detects that it is not rotating. (see via Ford-specific scan tools like IDS, FDRS, or advanced tools like FORScan.)
• C0020:15: ABS Pump Motor Control: Circuit Short to Battery or Open. Sets when the module detects an open/high resistance in the pump motor circuit or if voltage feedback is too high. (see via Ford-specific scan tools like IDS, FDRS, or advanced tools like FORScan.)

Scan Tool Commands That Help

• Ford IDS / FDRS / FORScan: ABS Pump Motor (PMP_MOTOR) Active Command — After verifying power and ground, use this command to toggle the ABS pump motor on. Listening for the motor to run is a direct test of its functionality. If it doesn't run, and wiring is good, the module/HCU is likely faulty.
• Ford IDS / FDRS: Programmable Module Installation (PMI) — This function is required after replacing the ABS module. It copies the configuration data from the old module (if possible) or downloads it from Ford's servers and writes it to the new module, configuring it for the specific vehicle's options (tire size, drivetrain, etc.).
• Ford IDS / FDRS: ABS Module Self-Test — This command initiates a comprehensive self-check of the ABS module and its related components, which can help confirm if a fault is still present after a repair attempt.

Wiring & Ground Locations

• G108 — On the driver's side front frame rail, often accessible from the wheel well area.. This is the specific ground point identified in TSB 21-2030 as the primary cause for code C0020 on these vehicles due to a manufacturing defect.
• C135 — The main electrical connector on the ABS module/HCU assembly.. This is the connector where all power, ground, and communication signals enter the ABS module. Pinpoint tests for voltage and resistance are performed here to diagnose the circuit.
• C135 Pin 13 & Pin 38 — Within the ABS module connector C135.. These are the primary ground pins for the ABS module. They use a Black/Yellow (BK/YE) wire. Testing resistance from these pins to the chassis is the definitive way to confirm the integrity of the G108 ground connection.
• C135 Pin 1 & Pin 25 — Within the ABS module connector C135.. These are the main power supply pins for the ABS module and pump. Pin 1 (Violet/Red) and Pin 25 (Blue/Red) should have constant battery voltage. A loss of voltage here points to a fuse or wiring issue upstream.

OEM Part Supersession History

• L1MC-2C219-BA → L1MZ-2005-F — Part number update for the ABS pump/modulator assembly.
  Heads up: Part numbers are extremely specific to vehicle options (AWD, FWD, adaptive cruise, etc.). Always verify the correct part number with the vehicle's VIN before ordering.

Model Year Variations Within This Range

• 2020 - early 2021: Vehicles built on or before December 24, 2020, are specifically called out in TSB 21-2030 as being prone to the G108 ground fault. Vehicles built after this date have the production fix and are less likely to experience this specific issue, making an actual module failure a slightly higher possibility.