Overview: This guide provides detailed troubleshooting steps for resolving issues related to the combustion air fan motor in Scania trucks’ auxiliary heater systems. The common error codes ATA 131 to ATA 134 are addressed, offering solutions to ensure the proper functioning of the heating system.
Related Resources:
- 2024.03 Scania SDP3 V2.59.3 V2.40 Diagnostic Software Free Download
- Scania VCI3 Diagnostic Adapter Full Chips
Troubleshooting Steps:
ATA 131: Combustion Air Fan Motor Failure to Start
- Issue: The auxiliary heater does not initiate.
- Cause: Disruption in the combustion air fan motor circuit.
- Important Note: Use an 18V motor only. Direct 24V connection can damage the motor.
- Resolution: Inspect the combustion air fan motor, referring to the electrical diagram for connection points. Measure resistance at points 1 and 2 in the control unit connector A. Expected resistance is around 4 ohms. Replace the control unit if necessary.
ATA 132: Short Circuit in Combustion Air Fan Motor Circuit
- Issue: The auxiliary heater won’t start.
- Cause: Short circuit within the combustion air fan motor circuit.
- Resolution: Same as ATA 131; inspect and measure resistance. Replace components as needed.
ATA 133: Fan Wheel Obstruction or Malfunction
- Issue: The fan wheel of the combustion air fan motor does not rotate.
- Cause: Blockage, excessive speed, or missing magnet in the fan wheel.
- Resolution: Verify the presence of the magnet on the fan wheel. Ensure the wheel is free of obstructions. Check the motor as in ATA 131 and 132.
ATA 134: Short Circuit or Overload of Combustion Air Fan Motor
- Issue: Potential short circuit or overload affecting the auxiliary heater’s combustion air fan motor.
- Cause: Possible electrical or mechanical fault in the motor, excessive voltage, or control unit issues.
- Important Note: Damage may occur if voltage exceeds 18V.
- Resolution: Inspect the auxiliary heater’s cable harness for short circuits. Evaluate the motor and control unit’s functionality and condition.
For additional support and information on troubleshooting Scania truck issues, please consult Scania Trouble Repair..