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Lincoln · Suspension · Critical code

C1727 on Lincoln: How to Diagnose & Fix

EPS Motor Circuit Malfunction

3 Lincoln models · 3 documented issues · 3 critical · $300-$2,500 repair

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C1727 by Lincoln model

  • 2003-2011Town Car1
  • 2003-2017Navigator1
  • 2020-2024Aviator1
  • FAQ

C1727 on other makes

  • Ford
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C1727 by Lincoln model

  • 2003-2011Town Car1
  • 2003-2017Navigator1
  • 2020-2024Aviator1
  • FAQ

C1727 on Lincoln by model: symptoms, diagnosis and fix

Link to this issueError Codes:C1727C1965

Final-gen Town Car (2003-2011 Panther platform) used a rear-only air suspension that develops bag leaks and compressor burnout very similar to the Navigator/Crown Vic Police Interceptor system. Cars sag dramatically overnight; compressor cycles continually trying to refill.

Common Symptoms

  • rear sag
  • compressor runs continuously
  • air suspension warning
  • rear bottoms out on bumps

How to Fix

Replace bags as a pair ($300-$600 aftermarket installed). Compressor + dryer kit ~$200-$400 installed. Many owners convert to coil springs with a Strutmasters-style kit (~$300-$500) — loses self-leveling but no further maintenance. Limo owners need to keep air for headroom adjustment.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Arnott A-2105 rear air spring, two required
    OEMArnott A-2105

    This issue is scoped to 2003-2011; confirm factory air equipment and order quantity two.

    AM AutoParts
  • AM AutoParts AM-1906992999 air-suspension compressor with dryer
    OEMAM-1906992999

    Do not install it as a first response to rea

    AM AutoParts
  • Arnott C-2615 rear coil-spring conversion kit with rear shocks
    OEMArnott C-2615

    Confirm 2003-2011 application and explain the loss of automatic load leveling before purchase; it is not the defau

    TruckSpring

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$300 - $1,200

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Link to this issueError Codes:C1727C1731C1965

2003-2017 Navigators with the optional/standard rear air suspension (and the 2003+ Expedition with the same system) develop air-bag leaks at the bag-to-piston seal as the bag rubber ages and cracks. Symptoms: rear of vehicle sagging overnight, compressor running constantly, error message "Check Air Suspension." Eventually the compressor burns out from constant duty.

Common Symptoms

  • rear sag
  • air suspension warning
  • compressor running constantly
  • uneven ride height

How to Fix

Replace air bags as a pair (Arnott or Strutmasters aftermarket ~$400-$700 per side; OEM Motorcraft ~$800-$1,200 per side installed). Replace the dryer with the compressor or it will quickly fail again. Some owners convert to coil springs (Strutmasters kit ~$700) — eliminates the leveling feature but is permanent.

Typical repair cost:$700 - $2,400

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Link to this issueError Codes:C1965C1727

2020+ Aviator with the optional Air Glide suspension shares its compressor and air spring design with the related Ford Explorer ST/Platinum. Owners report compressor noise becoming progressively louder by 40,000-80,000 miles, then bag leaks (rear first), then compressor burnout. Warning message: "Service Air Suspension."

Common Symptoms

  • rear sag overnight
  • compressor runs constantly
  • service air suspension message
  • uneven ride height

How to Fix

Diagnose with FORScan to confirm air bag vs. compressor failure. OEM bags $700-$1,100 per corner installed. Compressor (Wabco/Continental unit) ~$600-$900 installed. Replace compressor dryer at the same time as a bag (~$80) — extends compressor life.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • LC5Z-5A891-Q genuine Ford rear air spring, driver side, gas 3.0L
    OEMLC5Z-5A891-Q

    Replace a leak-confirmed left/driver rear spring on a non-PHEV Air Glide Aviator Fitment/availability: Live Add to Cart page identifies driver side, replaces LC5Z-5A891-K and lists 2020-2025 Aviator 3.0L gas fitment. Confirm VIN, Air Gli…

    FordPartsGiant
  • LC5Z-5A891-R genuine Ford rear air spring, passenger side, gas 3.0L
    OEMLC5Z-5A891-R

    Replace a leak-confirmed right/passenger rear spring on a non-PHEV Air Glide Aviator Fitment/availability: Live Add to Cart page identifies passenger side, replaces LC5Z-5A891-J and lists 2020-2025 Aviator 3.0L gas fitment. Confirm VIN, …

    FordPartsGiant
  • LC5Z-5A891-N genuine Lincoln rear air spring, driver side, 3.0L PHEV
    OEMLC5Z-5A891-N

    Replace a leak-confirmed left/driver rear spring on an Air Glide Grand Touring PHEV Fitment/availability: Live Add to Cart page identifies driver side, replaces LC5Z-5A891-M/-E and lists 2020-2023 Aviator 3.0L PHEV fitment. Do not substi…

    FordPartsGiant
  • LC5Z-5A891-P genuine Ford rear air spring, passenger side, 3.0L PHEV
    OEMLC5Z-5A891-P

    Replace a leak-confirmed right/passenger rear spring on an Air Glide Grand Touring PHEV Fitment/availability: Live Add to Cart page identifies passenger side, replaces LC5Z-5A891-L/-G and lists 2020-2023 Aviator 3.0L PHEV fitment. Do not…

    FordPartsGiant
  • LC5Z-5319-C genuine Ford air-suspension compressor/leveling assembly
    OEMLC5Z-5319-C

    Replace a compressor that fails electrical, command, pressure, run-time or thermal diagnosis after leaks are repaired Fitment/availability: Live official Ford direct product page identifies SKU LC5Z5319C and the four-corner air-suspensio…

    Ford Parts

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$700 - $2,500
Sources for this issue (2)
  • Ford SSM 51621: B1041/U2100 Diagnostic Service Modetsb
  • Ford SSM 51640: Front Air Spring/Strut Full Assembliestsb

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C1727 code reference

General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.

Frequently asked questions

What does C1727 mean on a Lincoln?

C1727 stands for "EPS Motor Circuit Malfunction." C1727 is a steering/chassis code indicating a malfunction in the Electric Power Steering (EPS) assist motor circuit. This motor provides the actual steering boost, and the EPS module monitors its electrical circuit for proper operation. When it detects an open, short, over-current, or otherwise out-of-spec condition in the motor circuit, it sets this code. It generally causes loss or reduction of power-steering assist (heavy, hard-to-turn steering) and an EPS/steering warning light, though the vehicle can still be steered manually with more effort. On Lincoln it is documented across 3 models: Town Car, Navigator, Aviator.

What are the most common causes of C1727?

The most common causes of C1727 are: Failed EPS assist motor, Open, shorted, or high-resistance wiring to the motor, Corroded or loose motor power/connector terminals, Low system voltage or poor ground to the EPS unit, Internal EPS control module driver fault, Overheated/over-current condition from excessive load, Damaged harness near the steering column or rack. The specific cause varies by vehicle.

How much does it cost to fix C1727 on a Lincoln?

Published repair estimates on Lincoln range from $300 to $2,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.

Related codes

  • C1725 · Steering Torque Sensor Circuit
  • C1726 · Steering Torque Sensor Signal Invalid
  • C1728 · EPS Motor Over-Temperature
  • C0327 · Excessive Lateral Acceleration Sensor Rate
  • C0710 · Steering Position Sensor
  • U0131 · Lost Communication with Power Steering Module

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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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