C1728 on Ford: How to Diagnose & Fix
EPS Motor Over-Temperature
1 Ford model · 1 documented issue · $300-$1,500 repair
C1728 on Ford by model: symptoms, diagnosis and fix
The 2003-2017 Ford Expedition with optional air suspension (standard on Eddie Bauer, King Ranch, Platinum, and EL/MAX trims) suffers from air suspension compressor failure, air spring leaks, and ride height sensor malfunctions. The compressor, located under the vehicle, is exposed to road debris, salt, and moisture which degrades the motor and valves. When air springs develop leaks, the compressor runs continuously trying to maintain ride height, leading to premature burnout. RepairPal estimates compressor replacement between $666 and $724, though dealer pricing can reach $1,200. NHTSA has received hundreds of complaints regarding air suspension failures. Strutmasters.com notes that 2007-2011 Expedition and Navigator share the same air suspension system and failure patterns. Many owners opt for air-to-coil spring conversion kits as a permanent, lower-cost solution.
Common Symptoms
- Rear of vehicle sagging or sitting noticeably lower
- Air suspension warning light or message on dash
- Compressor runs excessively or continuously
- Loud compressor noise from under the vehicle
- Harsh ride over bumps
- Vehicle leans to one side
- Hissing sound from air springs or compressor
- Vehicle bottoming out on speed bumps or driveway transitions
How to Fix
Most cost-effective permanent fix is an air-to-coil spring conversion kit from Strutmasters or Arnott ($300-500 for kit plus installation). If keeping air suspension: replace the compressor (Arnott P-2936 or Dorman 949-200, $200-400 part), both rear air springs ($150-250 each), and inspect all air lines for cracks. Always replace air springs in pairs. Compressor relay should also be checked - a corroded relay causes intermittent compressor operation. RepairPal estimates $666-724 for compressor replacement at a shop.
Sources for this issue (1)
C1728 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 C1728 mean on a Ford?
C1728 stands for "EPS Motor Over-Temperature." This chassis code relates to an over-temperature condition in the electric power steering (EPS) motor, the electric motor that provides power-assist for the steering. The steering control module monitors the motor's temperature (directly or by estimating it from current draw and time), and when it gets too hot the system sets this code and temporarily reduces or cuts steering assist to protect the motor from heat damage. Drivers often notice the steering becoming heavy until the system cools down. It frequently follows prolonged hard steering, but can also indicate an electrical fault that makes the motor draw excessive current. On Ford it is documented across 1 model: Expedition.
What are the most common causes of C1728?
The most common causes of C1728 are: Prolonged hard or full-lock steering causing thermal overload, Faulty or shorting EPS motor drawing excess current, Low system voltage forcing higher current draw, Faulty temperature sensor or estimation circuit, Wiring or connector fault in the EPS motor circuit, Failing EPS control module, Mechanical steering bind increasing motor load. The specific cause varies by vehicle.
How much does it cost to fix C1728 on a Ford?
Published repair estimates on Ford range from $300 to $1,500 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.
Looking for C1728 on a different make?
View C1728 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.