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C1260ModerateChassis

C1260: How to Diagnose & Fix — Steering Angle Sensor Circuit / Signal (manufacturer-specific)

12 vehicles · 3 makes · $50-$1,500 repair

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How to diagnose and fix C1260: most-reported vehicles

Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.

Kia K5 · 2021–2024

Link to this issueError Codes:C1260C1261

On 1.6T turbocharged K5 variants, some owners and NHTSA complainants have reported a hissing sound from the brake booster area upon brake pedal application, accompanied by a noticeably harder brake pedal and reduced power assistance. The GDi turbocharged engine uses an electric vacuum pump to supplement braking assist; failures or leaks in the vacuum pump, vacuum check valve, or booster hose connection reduce available vacuum and compromise brake pedal feel and stopping distance. This has been flagged as a safety concern in NHTSA filings.

Common Symptoms

  • Hissing sound when brake pedal is pressed
  • Hard or stiff brake pedal requiring significantly more force to stop
  • Longer stopping distances than normal
  • Brake warning light or low vacuum warning illumination
  • Brake pedal feel improving after engine warms up then worsening again

How to Fix

Inspection of the vacuum pump, vacuum reservoir, check valve, and all vacuum lines connecting to the brake booster is required. The electric vacuum pump (Kia/Mobis part number 59100-L2000 or per VIN) may require replacement if output is below specification. The vacuum check valve (a common failure point) is a lower-cost item at approximately $20–$50. Full vacuum pump replacement is $300–$700 parts and labor.

What you need to fix it

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

  • Genuine Kia 28810-2M810 mechanical brake-vacuum pump
    OEMKia 28810-2M810, superseded by 28810-2M831

    Replace the engine-driven pump after a vacuum-output test confirms pump failure Fitment/availability: 2021-2024 Kia K5 with 1.6L Gamma-II turbo; seller shows supersession to 28810-2M831. Confirm VIN and current EPC before ordering, and d…

    KiaPartsNow

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:$50 - $900

Research This Issue

Based on 31 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence31 owner reportsReviewed May 2026

Hyundai Sonata · 2015–2017

Link to this issueError Codes:C1260C1101

The Motor-Driven Power Steering (MDPS) unit can fail, illuminating the EPS warning light and causing sudden loss of power assist or a steering wheel that becomes very tight/hard to turn - sometimes during low-speed maneuvers (parking, tight turns) and sometimes at highway speed (~35 mph). Owners report having to stop, shift to park, and restart the engine to clear the light, and that the wheel can briefly 'lock' or require very high effort. Root causes traced to the MDPS module/motor, wiring-harness connections, or the steering-angle sensor. Hyundai issued a warranty extension covering the MDPS/EPS unit for EPS-warning-light illumination on 2016-2017 model-year vehicles from 5yr/60,000 mi to 15yr/150,000 mi.

Common Symptoms

  • EPS / MDPS warning light on
  • Sudden loss of power steering assist
  • Steering wheel very hard to turn or briefly locked
  • Loss of assist during tight low-speed turns or at ~35 mph
  • Light clears only after restarting the engine

How to Fix

Scan for MDPS-related codes and inspect the wiring harness/connectors and steering-angle sensor before condemning the unit; repairing a connection sometimes resolves it. A failed MDPS module is replaced. For 2016-2017 vehicles the MDPS/EPS unit is covered under the extended warranty (15yr/150,000 mi) when the EPS light illuminates - have it documented and repaired under that coverage.

Typical repair cost:$0 - $1,500
Sources for this issue (3)
  • Electronic Power Steering Failure - Hyundai Forumsforum
  • 71 Complaints: 2015 Hyundai Sonata Steering Problems - CarComplaintsforum
  • 2017 Sonata Power Steering Problem - Hyundai Forumsforum

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026

Audi A8 · 2019–2025

Link to this issueError Codes:C1260U1121

On air-suspension-equipped 2019-2025 Audi A8 vehicles, the cluster may show an air-suspension malfunction warning while the suspension controller stores C1260F0 or U112100 with symptom code 262400. Audi directs diagnosis toward communication, wiring and connector contacts between the suspension controller and compressor control module; the bulletin does not establish that every warning is a failed compressor, leaking spring or collapsed suspension.

Common Symptoms

  • Air-suspension malfunction warning in the instrument cluster

How to Fix

Record the complete DTC and symptom code and have an Audi-capable technician inspect the specified wiring and connector contacts. If no wiring or contact problem is found, continue the guided procedure in current Audi service information. Do not replace a compressor, spring or relay from this card alone.

Sources for this issue (1)
  • Audi TSB 2059363/6 - Air-Suspension Warning with C1260F0 or U112100tsb

Research This Issue

GoogleRedditYouTubeNHTSA
Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

Audi e-tron · 2019–2023

Link to this issueError Codes:C1260U1121

Audi TSB 2059363/5 covers a legacy e-tron air-suspension malfunction when suspension controller J775 stores C1260F0 for no communication with compressor-control unit J1135 or U112100 with symptom code 262400 for a missing message. This is an electrical communication path; the bulletin does not establish leaking air lines, worn struts, height-sensor failure, compressor burnout or ball-joint wear as one common defect.

Common Symptoms

  • Air-suspension malfunction warning
  • C1260F0 or U112100 symptom 262400 in suspension controller J775

How to Fix

Read the complete suspension DTC and symptom code, then inspect wiring, terminals and connectors between J775 and J1135 as Audi directs. If the fault is passive/sporadic on its first occurrence, clear it and verify operation. Replace J1135 if the fault is active/static after the electrical inspection or if C1260F0 or U112100 with symptom 262400 returns a second time as passive/sporadic. Diagnose vehicle sag, leak-down or compressor noise separately; do not order a compressor, air-supply unit or suspension parts from the former card.

Owner tips & cautions

  • TipAsk for the full DTC, symptom code and passive/sporadic versus active/static status before authorizing a control unit or mechanical suspension part.
Sources for this issue (1)
  • Audi TSB 2059363/5 - Air-Suspension Warning with C1260F0 or U112100tsb

Research This Issue

GoogleRedditYouTubeNHTSA
Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

Audi Q8 · 2019–2025

Link to this issueError Codes:C1260U1121

Audi TSB 2059363/6 applies to air-suspension-equipped 2019-2025 Q8 vehicles when the instrument cluster reports an air-suspension malfunction and suspension control unit J775 stores C1260F0 for no communication or U112100 for a missing message, both with symptom code 262400. The bulletin identifies communication with compressor-control unit J1135; it does not establish universal air-spring, strut or compressor wear.

Common Symptoms

  • Air-suspension malfunction warning in the instrument cluster

How to Fix

Inspect the wiring and connector contacts between J775 and J1135 before replacing a component. For a first passive or sporadic occurrence, clear the fault and release the vehicle. If the same passive fault returns a second time, or the fault is active or static after wiring inspection, Audi directs replacement of J1135 under current repair and parts information. Do not buy struts, springs, a compressor or a conversion kit solely from this warning.

Sources for this issue (1)
  • Audi TSB 2059363/6 - Air Suspension Warning with C1260F0 or U112100tsb

Research This Issue

GoogleRedditYouTubeNHTSA
Manually Verified
High ConfidenceVerifiedReviewed Jul 2026

Find C1260 by make

Browse every documented model and issue for your make.

Audi · 10 issuesHyundai · 1 issueKia · 1 issue

C1260 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 C1260 mean?

C1260 stands for "Steering Angle Sensor Circuit / Signal (manufacturer-specific)." C1260 is a chassis code most commonly defined as a fault in the steering angle sensor (SAS) circuit or signal, used widely on Hyundai/Kia and GM vehicles (some platforms apply it to a wheel-speed comparison fault instead). The ABS/stability-control module relies on the SAS to know the steering wheel's angle and direction for electronic stability control calculations, and it sets this code when that signal is missing, corrupt, or illogical. The result is typically disabled stability/traction control with warning lights. Because the exact definition varies by make, confirm against the vehicle's service data.

What are the most common causes of C1260?

The most common causes of C1260 are: Faulty steering angle sensor, Steering angle sensor needs recalibration/initialization, Worn steering coupler/clock spring (common on Hyundai/Kia), Damaged wiring or connector to the SAS, CAN communication fault between SAS and ABS module, Faulty ABS/ESC control module, Recent steering or suspension work without recalibration. The specific cause varies by vehicle.

How much does it cost to fix C1260?

Repair costs for C1260 range from $50 to $1,500, depending on the vehicle and root cause.

Which vehicles are affected by C1260?

Au7o has documented C1260 across 12 vehicle models from 3 manufacturers: Audi, Hyundai, Kia.

Related codes

  • C1261 · Manufacturer-Specific Chassis Code (Steering Angle Calibration or ABS Inlet Valve Solenoid)
  • C0031 · Left Front Wheel Speed Sensor Circuit
  • C0034 · Right Front Wheel Speed Sensor Circuit
  • C0036 · Left Front Wheel Speed Sensor Circuit
  • C0037 · Left Rear Wheel Speed Sensor Circuit
  • C0038 · Left Rear Wheel Speed Sensor Circuit
  • C003A · Right Rear Wheel Speed Sensor Circuit
  • C003B · Right Rear Wheel Speed Sensor Supply Circuit
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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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