C1288

What the Code Means

Code C1288 points to a fault in the primary input of the pressure sensor (brake fluid pressure sensor). This sensor is built into the ABS unit and feeds critical data to the DSC (Dynamic Stability Control) system. A faulty sensor causes DSC and ABS to misbehave, since the system can't accurately read brake line pressure.

Symptoms

• ABS and DSC warning lights come on in the instrument cluster
• Incorrect brake fluid pressure readings in diagnostic data
• Possible loss of ABS and DSC functions (the system may drop into limp mode)

Diagnosis and Repair

Step 1: Scan for Codes

Hook up a diagnostic scanner (ISTA or INPA) and pull the fault codes. Confirm that C1288 is active.

Step 2: Check Live Data

Read the pressure sensor values in live data. Compare them against expected values (for example, while pressing the brake pedal).

Step 3: Replace or Repair the ABS Unit

The pressure sensor is built into the ABS unit and isn't sold separately. The ABS unit (hydraulic assembly) has to be replaced or rebuilt.

Step 4: Bleed the Brake System

After replacing the ABS unit, bleed the brake system to remove air.

Step 5: Clear the Codes

After the repair, clear the fault codes and take a test drive to verify.

Secondary Problems

Ignoring the fault can lead to:

• Loss of stability control (DSC) and anti-lock brake (ABS) functions
• Higher crash risk during emergency maneuvers or on slippery surfaces
• Incorrect operation of the brake system overall