This article analyzes common error codes, like 57 (0x39), on the E46 SMG pump due to the pump’s inability to generate proper system pressure. The SMG pump usually activates to create a specific pressure range, most noticeable when the vehicle has been idle for a lengthy period. The majority of this fluid pressure is retained in the accumulator for future shifting and clutch operations.
Error code 57 (0x39) arises when the DME encounters unexpected pressure fluctuations. There are several potential causes, listed here in order of commonality:
- Electric motor failure: The motor may not provide enough torque or speed to build pressure within the set time frame, leading eventually to total motor failure.
- High power relay (salmon relay) damage: This is often tied to motor problems, as extra load can cause high current and wear out the relay. A malfunctioning relay could trigger additional codes when stuck in either the ON or OFF position.
- Low SMG fluid level: This can allow air into the pump, preventing pressure build-up. Bleeding the system is recommended to remove residual air.
- External hydraulic leaks: These can reduce fluid levels, causing low pressure. Inspect for leaks, particularly at the SMG slave cylinder or actuator.
- Faulty pressure sensor: This can give the DME a false low-pressure reading, causing the pump to run excessively.
- Pressure accumulator outside specifications: If the accumulator cannot store enough reserve pressure, the pump may need to activate more often.
- Wiring harness or fuse damage: This can occur if the relay gets stuck in the ON position, causing wire harness overheating and insulation damage.
- Internal hydraulic leaks: Worn-out SMG system parts can allow pressurized fluid to leak back into the reservoir. Check for damaged solenoid valve seals, worn pressure relief valves, and damaged solenoid valves.
This comprehensive guide will help identify and address any issues related to E46 M3 SMG cog light error code 57 (0x39).
