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Tahoe / Yukon Service Manual

DTC C05B0

Diagnostic Instructions Perform the Diagnostic System Check prior to using this diagnostic procedure: Diagnostic System Check - Vehicle Review the description of Strategy Based Diagnosis: Strategy Based Diagnosis An overview of each diagnostic category can be found here: Diagnostic Procedure Instructions DTC Descriptor DTC C05B0 Hydraulic Brake Circuit Leak Detected - Level 2 Symptom Byte Information: Symptom Byte List Circuit/System Description For an overview of the component/system, refer to: ABS Description and Operation Conditions for Running the DTC Ignition/Vehicle = OFF Conditions for Setting the DTC Antilock Braking System = Leaking Actions Taken When the DTC Sets ABS Indicator Control = ON Traction/Stability Control Indicator = ON Brake System Warning Indicator = ON Conditions for Clearing the DTC The conditions for setting the DTC no longer exist. A history DTC will clear after 40 consecutive malfunction-free ignition cycles. Diagnostic Aids If during testing the Brake Hydraulics Test still fails after performing the Hydraulic Brake System Bleeding at least 3 times, performing the scan tool control function test Brake System Hydraulics Corner Test can be performed to help isolate the concern. The Brake System Hydraulics Corner Test is not to be used in place of the Brake Hydraulics Test. Inspect the calipers, check for worn or tapered pads, seized pistons or guide pins. Refer to: Disc Brake System Diagnosis Reference Information Schematic Reference Antilock Brake System Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition/Vehicle » Off
  2. Verify there are no leaks in the component/system: Brake System » Refer to: Brake Fluid Loss
  3. Verify the brake pads are fully seated ⇒ If the brake pads are not fully seated 3.1. Disconnect the battery 3.2. Gradually apply the brake pedal to approximately 2/3 of its travel distance. 3.3. Wait 15 seconds and repeat until pedal is firm. 3.4. Reconnect battery. 3.5. Verify DTC C05B0 is not set. ⇒ If DTC C05B0 is not set All OK. ⇓ If DTC C05B0 is set ⇓ If the brake pads are fully seated
  4. Ignition » On / Vehicle » In Service Mode
  5. Clear code DTC C05B0 ⇒ If code does not reset All OK. ⇓ If code does reset
  1. Perform the scan tool control function: Brake Hydraulics Test ⇒ If the procedure/test does not pass Refer to: Hydraulic Brake System Bleeding ⇓ If the procedure/test passes
  2. Ignition/Vehicle » Off
  3. Ignition » On / Vehicle » In Service Mode
  4. Verify DTC C05B0 is not set. ⇒ If DTC C05B0 is set Replace the component: Brake Master Cylinder ⇓ If the DTC is not set
  5. All OK. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair: Diagnostic Repair Verification Brake Master Cylinder Replacement - With Power Brake Booster and Electronic Brake Control Module For control module replacement, programming, and setup refer to: Control Module References