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.
1990 Ford Bronco II RWD, Standard, M5OD-R1FACTORY OEM SERVICE PROCEDURE
Traction Control: Anti-Lock
- Anti-Lock Brake Safety Precautions
- Description & Operation
- Bleeding Brake System
- Trouble Shooting
- Diagnosis
- Retrieving Trouble Codes
- Trouble Codes
- No Codes
- Code 1
- Code 2 (Open Isolate Circuit)
- Code 3 (Open Dump Circuit)
- Code 4 (Closed Valve Switch Or Open Dump Valve) Bronco, "E" & "F" Series
- Aerostar, Explorer, Ranger & Navajo
- Code 5 (System Dumps Too Many Times)
- Code 6 (Speed Sensor Signal Rapidly Cuts In And Out)
- Code 7 (No Isolate Valve Self-Test)
- Code 8 (No Dump Valve Self-Test)
- Code 9 (High Sensor Resistance)
- Code 10 (Low Sensor Resistance)
- Code 11 (Stoplight Switch Circuit)
- Code 12 (Fluid Level Switch Closed During A Stop) Bronco, "E" & "F" Series
- Code 12 (Loss Of Brake Fluid For One Second During Stop) Aerostar, Explorer, Navajo & Ranger
- Code 13 (Speed Sensor Check)
- Code 14 (Program Check)
- Code 15 (Memory Failure)
- Code 16 (Aerostar)
- Testing
- Notes
- Test A - Yellow Light Off & Does Not Self-Check
- Test B - Red Light On, Yellow Light Off & Does Self-Check
- Test C - Yellow & Red Lights On Steady
- Test D - Yellow Light On, Red Light Off
- Test E - Yellow Light Flashing & Red Light Off
- Test F - Lights Okay & Rear Wheels Lock-Up
- Test G - Yellow Light Self-Checks, Red Light Does Not Self-Check
- Removal & Installation
- Torque Specifications
- Wiring Diagrams
Factory Service Tools
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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.