Safety Warning

DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.

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HOMESERVICE MANUALSHYUNDAI2014EQUUS SIGNATUREREPAIR AND DIAGNOSIS (SINGLE PAGE)BRAKESANTI-LOCK BRAKESELECTRONIC STABILITY CONTROL (ESC) DIAGNOSISDTC C1235: PRIMARY PRESSURE SENSOR-ELECTRICALCOMPONENT INSPECTION

2014 Hyundai Equus Signature

Component Inspection

2014 Hyundai Equus SignatureSECTION Component Inspection

IG "OFF".
IG "ON".
Connect GDS and select "Diagnostic Trouble Codes (DTC)" mode.
Using a GDS, Clear DTC.
Check if the pressure sensor's service data shows '0 bar' on the GDS while not pressing the brake pedal.
Use the GDS and check that the pressure sensor value rises while pressing the brake pedal.
Is the pressure sensor's data unusually shown?
YES
- Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NOTE:
  * In a case of replacing HECU, perform following functions
  1. "Steering Angle Sensor Calibration" for steering angle sensor offset correction (refer to C1261 ) -ESP (ESC) only
  2. "Longituginal Sensor Calibration" for Longituginal sensor offset correction (refer to C1285 ) - ESP (ESC) only
  3. "Variant Coding" for option coding (refer to C1702 )
NO
- This fault is intermittently caused by pressure sensor. Go to "VERIFICATION OF VEHICLE REPAIR " procedure.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.