C1B00 on Ford: How to Diagnose & Fix
Steering Angle Sensor Fault
4 Ford models · 4 documented issues · 4 critical · $900-$3,500 repair
C1B00 on Ford by model: symptoms, diagnosis and fix
The 2011-2016 F-150 uses a belt/column electric power-assist steering (EPAS) system that replaced the old hydraulic pump. Owners report the dash lighting up with a 'Power Steering Assist Fault — Service Now' or wrench warning, after which the assist cuts out and the wheel becomes very heavy, often at low speed in parking lots or during a turn. The failure is usually an intermittent electrical connection or a failed torque/steering-angle sensor or the EPAS motor buried in the rack, sometimes triggered by low battery voltage or a software calibration fault. While the F-150 was not part of Ford's large 2011-2013 sedan EPAS recall (423k Flex/Taurus/MKS), the truck shares the failure mode and it is heavily reported on owner forums.
Common Symptoms
- 'Power Steering Assist Fault' or wrench warning on dash
- Steering wheel suddenly very heavy / hard to turn
- Intermittent loss of assist, often at low speed or when turning
- Fault clears after restart then returns
- Whining or clunk from steering when assist drops
How to Fix
Scan for EPAS/steering DTCs and check battery voltage and the C-connector at the steering gear first (a poor connection or low voltage can trip the fault without a bad rack). Reflash the PSCM with the latest Ford calibration if applicable. If the motor or internal sensor has failed, the fix is a complete steering rack/gear assembly replacement (motor is non-serviceable). Always verify charging system health before condemning the rack.
Sources for this issue (3)
The 2012 Mk3 Focus was the first Focus with a fully electric rack-mounted power steering assist (EPAS). The torque/position sensor and motor assembly inside the rack, and the power steering control module (PSCM) integrated with it, fail intermittently - often heat-soaked on long drives or hot days. The dash shows "Power Steering Assist Fault - Service Now", the wheel goes heavy with no warning, and steering no longer self-centers. Failures are frequently intermittent at first (assist returns after a key cycle) and then become permanent. Because the assist motor is integral to the rack, Ford's repair is a complete steering gear replacement. Unlike the Fusion/Taurus/Flex family, which got NHTSA recall 15V340 for the same motor-sensor defect, the Focus was never recalled despite hundreds of NHTSA complaints, and was instead the subject of a class-action suit covering 2012-2014 Focus and Focus Electric.
Common Symptoms
- Power Steering Assist Fault - Service Now message
- Steering suddenly becomes very heavy while driving
- Assist comes back after restarting the car
- Steering does not return to center after a turn
- Fault appears more often on hot days or after long drives
How to Fix
Scan the PSCM for stored codes first (low battery voltage and corroded connectors at the rack can mimic the fault). If EPAS-internal codes are present, Ford's only repair is replacement of the complete electric steering gear assembly and PSCM software programming; some cars are fixed by a PSCM reflash alone when no hard codes are stored. Verify battery and alternator output before condemning the rack, since low system voltage will drop assist and set the same message.
Sources for this issue (5)
- Power steering assist fault | Focus Fanatics Forumforum
- Sudden and complete steering failure | Focus Fanatics Forumforum
- NHTSA Recall 15V340 - Ford, Failure of Electric Power Steering Assist (same motor sensor defect, Focus excluded)article
- Ford Steering Problems Come into Focus - Safety Research & Strategiesarticle
- 2012 Ford Focus Power Steering Failure: 122 Complaints - CarComplaintsarticle
Multiple Bronco owners reported sudden loss of power steering assist, often accompanied by warning messages and very heavy manual steering effort at low speeds. The issue has been tied to failures in the electric power steering system and steering gear/rack assembly, and Ford issued a safety recall (23V155) for certain 2022 Bronco Raptor and 2023 Bronco Wildtrak vehicles because a cracked steering gear ball nut retainer could cause increased steering effort or prevent the steering wheel from turning. Owner complaints and forum reports describe intermittent assist loss first, then complete failure requiring rack replacement.
Common Symptoms
- Power steering assist fault message
- Very heavy steering effort
- Intermittent steering assist loss
- Steering wheel jerks or binds
- Warning lights on dash
How to Fix
Scan the PSCM/ABS modules for steering-related faults and inspect for active recalls or field service actions before replacing parts. Dealers typically replace the steering gear/rack assembly and perform module calibration; in intermittent cases, wiring and connector checks at the rack and battery voltage verification are also important. If recall coverage applies, the repair should be completed through Ford rather than paid out of pocket.
Sources for this issue (3)
2011-2014 Mustangs equipped with electric power steering can experience sudden loss of steering assist, often accompanied by a wrench light and a 'Service AdvanceTrac' or steering assist warning. No NHTSA safety recall covers steering on 2011-2014 Mustangs, so repairs are typically out of pocket once warranty has expired. Owners describe steering becoming very heavy at low speeds or during parking maneuvers, creating a clear safety concern.
Common Symptoms
- Sudden loss of power steering assist
- Steering becomes very heavy
- Wrench light illuminated
- Service AdvanceTrac message
- Intermittent steering assist after restart
How to Fix
Scan the PSCM for steering-related DTCs and verify whether the VIN is covered by recall or field service action. Repairs may include software updates, torque sensor/steering gear replacement, or replacement of the electric power steering assembly depending on the fault. Battery and charging system health should also be checked because low voltage can aggravate EPS faults.
Sources for this issue (3)
C1B00 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 C1B00 mean on a Ford?
C1B00 stands for "Steering Angle Sensor Fault." C1B00 is a manufacturer-specific chassis code (commonly Ford) indicating the power steering or stability control module detected a fault with the steering angle (steering wheel position) sensor. This sensor tells stability control and electric power steering where the steering wheel is pointed, which is essential for traction/stability control and assist calibration. When the signal is missing, erratic, or fails plausibility checks, the module sets this code and may disable stability control and reduce or alter power steering assist. Steering still works mechanically, but related driver-assist systems may be limited. On Ford it is documented across 4 models: F-150, Focus, Bronco, Mustang.
What are the most common causes of C1B00?
The most common causes of C1B00 are: Faulty steering angle sensor / clockspring assembly, Calibration not performed after alignment, battery, or steering service, Damaged or corroded sensor wiring/connector, Erratic or implausible sensor signal vs. other inputs, Power steering control module fault, Low system voltage or poor ground, Worn or damaged steering column components. The specific cause varies by vehicle.
How much does it cost to fix C1B00 on a Ford?
Published repair estimates on Ford range from $900 to $3,500 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.
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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.