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DTC C1241 Toyota
The diagnostic trouble code (DTC) C1241 for Toyota vehicles is related to the brake control system, specifically indicating an issue with the power supply or low voltage.
Code Definition
- Code: C1241
- Description: “Low Battery Positive Voltage or Abnormal Power Supply Voltage in ABS Control Module”
What Does C1241 Mean?
The Anti-lock Brake System (ABS) and/or Vehicle Stability Control (VSC) system rely on a stable power supply for proper operation. If the voltage supplied to the brake control module is too low or inconsistent, the system may not function correctly. This DTC is set when the detected voltage falls outside the acceptable range.
Common Causes of C1241
- Weak or Discharged Battery:
- A failing or discharged battery can cause low voltage.
- Faulty Alternator:
- An alternator not charging the battery correctly can lead to voltage drops.
- Electrical Load:
- Excessive electrical load (lights, accessories, etc.) can strain the system.
- Wiring Issues:
- Damaged, corroded, or loose battery terminals or wiring can cause voltage fluctuations.
- Brake Booster Pump Malfunction:
- A failing pump in hybrid or ABS systems can trigger this code.
- Defective ABS Control Module:
- Rarely, the ABS module itself may fail and report incorrect voltage.
Symptoms of C1241
- ABS or VSC Warning Light: Illuminated warning lights on the dashboard.
- Reduced Brake Assist: Decreased effectiveness of ABS or VSC functions.
- Other Electrical Issues: Flickering lights or weak starts due to low voltage.
- No Symptoms: The vehicle may appear to function normally despite storing the code.
Diagnostic Steps
- Check Battery Voltage:
- Use a multimeter to measure battery voltage (should be 12.6–12.8V when the car is off and 13.7–14.7V when running).
- Inspect Charging System:
- Test the alternator’s output and ensure it is charging the battery correctly.
- Visual Inspection:
- Check battery terminals, cables, and ground connections for damage or corrosion.
- Scan for Related Codes:
- Use a compatible OBD-II scanner to check for other electrical or ABS-related codes.
- Test the Brake Booster Pump:
- For hybrid vehicles, ensure the brake booster pump is operating as expected.
- Inspect ABS Module:
- Verify the module’s power supply and ground connections.
Common Fixes
- Replace or Recharge the Battery:
- Install a new battery if it’s old, weak, or not holding a charge.
- Repair the Charging System:
- Replace or repair the alternator if it’s underperforming.
- Clean or Tighten Connections:
- Remove corrosion and tighten loose battery terminals or wiring.
- Reduce Electrical Load:
- Turn off unnecessary electrical accessories to reduce strain on the system.
- Repair or Replace the ABS Module:
- If the module is defective, replace it as a last resort.
Estimated Repair Costs
- Battery Replacement: $100–$300
- Alternator Replacement: $400–$800
- Battery Terminal Cleaning or Repair: $50–$100
- Brake Booster Pump Repair (Hybrid): $500–$1,500
- ABS Module Replacement: $500–$1,200
Preventive Tips
- Monitor Battery Health: Regularly check the battery’s condition and replace it as needed.
- Keep Connections Clean: Prevent corrosion on battery terminals by using protective sprays.
- Avoid Overloading Electrical Systems: Use accessories sparingly, especially in older vehicles.
- Perform Regular Maintenance: Have the charging and braking systems inspected during routine service.