Description:

This diagnostic trouble code (TCU 524227.12) is generated if the filter bypass valve (coldweather starting) is open while transmission input speed (engine speed) is above 1400 rpm and transmission oil temperature exceeds +30°C (86°F). If diagnostic trouble code TCU 000127.01 is also stored, process this code first.

Reaction:

When this error code is detected, the equipment may experience issues related to incorrect operation of the filter bypass valve under specified conditions, potentially leading to performance problems. The system might display warnings or enter a protective mode to prevent further issues.

Recommendations:

1. Address Related DTCs:

• Process TCU 000127.01 First: Resolve any issues related to transmission oil pressure before addressing this code.

2. Inspect Filter Bypass Valve:

• Verify Operation: Ensure that the filter bypass valve is functioning correctly and not opening by mistake.
• Check Conditions: Verify the operating conditions to ensure they align with the expected parameters for the filter bypass valve.

3. Verify Sensor Readings:

• Check Temperature Sensors: Ensure that the transmission oil temperature sensor is providing accurate readings.
• Inspect for Errors: Look for any discrepancies in the sensor data that could lead to incorrect valve operation.

4. Examine Wiring and Connectors:

• Inspect Wiring: Check all wiring and connectors associated with the filter bypass valve and related sensors for damage or disconnection.
• Repair or Replace: Repair or replace any faulty wiring or connectors.

5. Verify Control Unit Functionality:

• Test Control Unit: Ensure that the control unit is correctly processing signals from the filter bypass valve and related sensors.
• Update Software: Update the control unit software if necessary.

Note:

Maintaining accurate sensor readings and proper operation of the filter bypass valve is essential for optimal performance during varying temperature conditions. Regular inspections and prompt repairs can help prevent issues related to incorrect valve operation.