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 MANUALSGMC1999FORWARD CONTROL 5.7 R, AUTOMATICREPAIR AND DIAGNOSISBRAKESTRACTION CONTROLANTI-LOCK BRAKE SYSTEM
1999 GMC Forward Control 5.7 R, Automatic
Anti-Lock Brake System
1999 GMC Forward Control 5.7 R, AutomaticSECTION Anti-Lock Brake System
- Model Identification
- Description
- Operation
- Bleeding Brake System
- Diagnosis & Testing
- Symptom Tests
- Diagnostic Tests
- Notes
- DTC C0221: Right Front Wheel Speed Sensor Circuit Open
- DTC C0222: Right Front Wheel Speed Sensor Signal Missing
- DTC C0223: Right Front Wheel Speed Sensor Signal Erratic
- DTC C0225: Left Front Wheel Speed Sensor Circuit Open
- DTC C0226: Left Front Wheel Speed Sensor Signal Missing
- DTC C0227: Left Front Wheel Speed Sensor Signal Erratic
- DTC C0229: Drop Out Of Front Wheel Speed Sensor Signals
- DTC C0235: Rear Speed Sensor Signal Circuit Open Or Grounded (Gasoline Engines)
- DTC C0235: Rear Speed Sensor Signal Circuit Open Or Grounded (Diesel Engines)
- DTC C0236: Rear Speed Sensor Signal Missing (Gasoline Engines)
- DTC C0236: Rear Speed Sensor Signal Missing (Diesel Engines)
- DTC C0237: Rear Speed Sensor Signal Erratic (Gasoline Engines)
- DTC C0237: Rear Speed Sensor Signal Erratic (Diesel Engines)
- DTC C0238: Wheel Speed Signal Malfunction
- DTC C0241: Right Front Isolation Solenoid Circuit Open
- DTC C0242: Right Front Dump Solenoid Circuit Open
- DTC C0243: Right Front Isolation Solenoid Circuit Shorted
- DTC C0244: Right Front Dump Solenoid Circuit Shorted
- DTC C0245: Left Front Isolation Solenoid Circuit Open
- DTC C0246: Left Front Dump Solenoid Circuit Open
- DTC C0247: Left Front Isolation Solenoid Circuit Shorted
- DTC C0248: Left Front Dump Solenoid Circuit Shorted
- DTC C0251: Rear Isolation Solenoid Circuit Shorted
- DTC C0252: Rear Dump Solenoid Circuit Open
- DTC C0253: Rear Isolation Solenoid Circuit Shorted (Except "L" & "M" Series)
- DTC C0254: Rear Dump Solenoid Circuit Shorted
- DTC C0265: Pump Motor Relay Circuit Open
- DTC C0266: Pump Motor Relay Circuit Shorted
- DTC C0267: Pump Motor Circuit Open (Except "L" & "M" Series)
- DTC C0267: Pump Motor Circuit Open ("L" & "M" Series)
- DTC C0268: Pump Motor Locked Or Pump Motor Circuit Shorted (Except "L" & "M" Series)
- DTC C0268: Pump Motor Locked Or Circuit Shorted ("L" & "M" Series)
- DTC C0269 Or C0274: Excessive Dump/Isolation Time
- DTC C0271, C0272 & C0273: EBCM Internal Fault
- DTC C0281: Stoplight Switch Always Closed Or Shorted
- DTC C0286: Anti-Lock Indicator Light Circuit Shorted To Battery Voltage
- DTC C0288: Brake Warning Light Circuit Shorted To Battery Voltage
- Removal & Installation
- Torque Specifications
- Wiring Diagrams
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.