OBD Guide

C1239

ABS Hydraulic Pressure Differential Switch Input Open Circuit

C1239 is an OBD-II diagnostic trouble code meaning: ABS Hydraulic Pressure Differential Switch Input Open Circuit. Common causes: broken or damaged sensor wiring harness, oxidation of sensor contacts. Estimated repair cost: $56–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$56–167 (est.)

Symptoms

  • The ABS indicator on the dashboard is on
  • Disabling the ABS system
  • Incorrect operation of the anti-lock braking system

Causes

  • Broken or damaged sensor wiring harness
  • Oxidation of sensor contacts
  • Differential pressure sensor malfunction
  • Problems with the ABS control unit

How to Fix

  1. Check the integrity of the sensor wiring harness
  2. Clean the sensor contacts from oxidation
  3. Check sensor resistance
  4. If necessary, replace the differential pressure sensor
  5. Check the operation of the ABS control unit

Related codes

FAQ

What does the C1239 code mean?

C1239 is an OBD-II diagnostic trouble code that indicates: ABS Hydraulic Pressure Differential Switch Input Open Circuit

What causes a C1239 error code?

The most common causes of C1239 include: Broken or damaged sensor wiring harness; Oxidation of sensor contacts; Differential pressure sensor malfunction; Problems with the ABS control unit.

How do I fix a C1239 diagnostic trouble code?

To fix C1239: Check the integrity of the sensor wiring harness. Clean the sensor contacts from oxidation. Check sensor resistance. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with C1239?

Limited driving only, diagnose soon

How much does it cost to fix C1239?

The estimated repair cost for C1239 is $56–167. Actual cost depends on your vehicle, location, and labor rates.

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