DCT Mechatronic Unit Internal Fault
2012-2018 BMW 328i 2.0L Turbo I4
Description
The mechatronic unit (combined TCM and hydraulic valve body in DCT transmissions) has detected an internal electronic or hydraulic fault.
Symptoms
- Check Engine Light
- Transmission warning light
- Multiple gear selection faults
- Erratic shifting behavior
- Limp mode in fixed gear
- Loss of drive intermittently
Common Causes
- Mechatronic electronic board failure
- Internal solenoid failure
- Hydraulic valve body wear
- Pressure accumulator leak
- Temperature sensor within unit failed
Diagnostic Steps
- Read mechatronic unit internal fault codes
- Check hydraulic fluid level in mechatronic
- Monitor solenoid commands vs responses
- Test temperature sensor readings
- Perform mechatronic self-test sequence
Repair Notes
Replace or rebuild mechatronic unit. Some manufacturers offer refurbished units. Requires special filling and bleeding procedures.
Related Codes
Other Powertrain Codes
- P0001Fuel Volume Regulator Control Circuit/Open
- P0002Fuel Volume Regulator Control Circuit Range/Performance
- P0003Fuel Volume Regulator Control Circuit Low
- P0004Fuel Volume Regulator Control Circuit High
- P0010Intake Camshaft Position Actuator Circuit/Open Bank 1
- P0011Intake Camshaft Position Timing Over-Advanced Bank 1
- P0012Intake Camshaft Position Timing Over-Retarded Bank 1
- P0013Exhaust Camshaft Position Actuator Circuit/Open Bank 1
- P0014Exhaust Camshaft Position Timing Over-Advanced Bank 1
- P0015Exhaust Camshaft Position Timing Over-Retarded Bank 1
P3046 on Other Vehicles
Common Questions
What does code P3046 mean on a 2012-2018 BMW 328i?
P3046 stands for "DCT Mechatronic Unit Internal Fault". The mechatronic unit (combined TCM and hydraulic valve body in DCT transmissions) has detected an internal electronic or hydraulic fault.
What are the symptoms of P3046 on a BMW 328i?
Common symptoms of P3046 include: Check Engine Light, Transmission warning light, Multiple gear selection faults, Erratic shifting behavior, Limp mode in fixed gear, Loss of drive intermittently.
What causes P3046 on a 2012-2018 BMW 328i?
Common causes of P3046 include: Mechatronic electronic board failure, Internal solenoid failure, Hydraulic valve body wear, Pressure accumulator leak, Temperature sensor within unit failed.