FAQ
TL;DR: BMW E60/E63 Active Steering faults often log 0x613A when supply dips below 7.5 V; many owners report “the processor does not get up.” Alternator events, firmware corruption, and BGA/power-stage faults are common roots. [Elektroda, MIKUr1, post #16838946]
Why it matters: This FAQ helps DIYers and techs diagnose and repair Active Steering driver failures, voltage errors, and comms issues fast.
Quick Facts
- Typical fault set: 0x612C “hardware error control device” and 0x613A “Supply voltage Kl.30.” [Elektroda, MIKUr1, post #16842036]
- Kl.30 is battery supply; verify feed and grounds per BMW’s power-supply diagram before ECU work. [Power supply for Active Steering]
- Post-alternator repair, a replacement AS controller worked after VIN rewrite. [Elektroda, MIKUr1, post #16847163]
- BDM access: built like EDC16; use the same BDM method to read MPC. [Elektroda, marcin_70, post #16886241]
- Alternator over/under-charge and 2–3 jump-starts preceded some failures. [Elektroda, MIKUr1, post #16841663]
What do BMW Active Steering codes 0x612C and 0x613A actually mean?
0x612C flags an internal hardware error in the AS controller. 0x613A indicates the module sees low supply at Kl.30. If 0x613A logs, verify battery, charging system, fuses, and grounds before opening the ECU. Clear codes, road-test, and re-scan to confirm persistence. [Elektroda, MIKUr1, post #16842036]
Should I try BGA reballing on the Active Steering ECU?
Yes, if power and firmware checks pass but the module still won’t boot, reballing the BGA can restore processor-to-board connections. A pro advised, “Do a BGA reballing first.” Perform only after stable supply verification and code reads. Use proper rework profiles to avoid pad lift. [Elektroda, seat21, post #16840640]
My alternator failed and AFS died afterward—are they related?
Yes. Reports show AFS failure right after alternator over/under‑charge episodes and 2–3 jump-starts. Voltage swings can trip 0x613A and stress the controller. Inspect charging output, battery condition, and grounds. If supply is stable yet AFS stays offline, proceed to firmware and hardware checks. [Elektroda, MIKUr1, post #16841663]
Can flashing with DIS/ISTA recover a nonresponsive Active Steering unit?
If there is communication, attempt a software flash with DIS/ISTA before hardware work. This can restore corrupted calibration or firmware. Ensure a fully charged battery and a stable charger during programming. If flashing fails or comms drop, continue with bench reading via BDM. [Elektroda, seat21, post #16841852]
How do I connect BDM to read the AS controller’s MPC?
It’s built like EDC16. Use an EDC16 BDM adapter to contact the MPC pads, read the dump, compare, and repair if needed. 1) Identify BDM pads and align the EDC16 probe. 2) Read and save full MPC contents. 3) Compare with a good dump and write back corrected data if corrupt. “You can copy the batch from the new to the old.” [Elektroda, marcin_70, post #16886241]
What does an “all FFFF” MPC dump indicate, and how do I fix it?
An “all FFFF” dump indicates erased or unread firmware/calibration data in the MPC flash. Read the working replacement unit, then write its corresponding batch to the original, matching part and software levels. Recode if needed, then clear faults and test drive. [Elektroda, marcin_70, post #16886241]
Do I need to code the VIN after swapping the AFS controller?
Yes. A used controller typically works only after VIN rewrite and coding to the vehicle. One case restored full AFS operation immediately after writing the car’s VIN into the donor module. Always verify steering angle calibration afterward. [Elektroda, MIKUr1, post #16847163]
Where can I find the official power-supply and pin references for AFS?
Use BMW’s technical information: the Active Steering power-supply page shows feeds, grounds, fusing, and signal routing. Follow it to verify Kl.30, ignition feeds, and earth points before suspecting ECU hardware. Print the diagram for step-by-step probing. [Power supply for Active Steering]
Could water on the passenger floor kill the AFS module even if the PCB looks dry?
Yes, cabin water ingress correlates with AFS issues, but the ECU may still appear dry. Moisture can affect connectors or wiring under carpet. After drying, inspect harness splices and measure supply at the module. If faults persist, proceed to firmware checks. [Elektroda, adamek2828, post #18550496]
Can jump-starting or a weak battery corrupt the AFS firmware?
Owners observed AFS faults after repeated jump-starts and weak batteries. Voltage transients can coincide with software issues. Stabilize the electrical system, then diagnose. If corruption is suspected, confirm via BDM read and compare with a known-good dump. [Elektroda, adamek2828, post #18550496]
What is Kl.30 in this context, and what should I measure?
Kl.30 is the unswitched battery supply input to vehicle modules. Verify battery voltage at Kl.30 at the AFS connector and across grounds per the BMW diagram. If the module logs low Kl.30, fix supply faults before reflashing or reballing. [Power supply for Active Steering]
ISTA/DIS sees the module but flags 0x612C—what next?
0x612C suggests an internal controller fault. After confirming stable power and grounds, check firmware integrity via BDM. If the dump is corrupt, repair by cloning or rewriting matched software. If software is intact, consider BGA rework. [Elektroda, MIKUr1, post #16842036]
Orientation tip: how are the BDM points laid out on this board?
With the controller connector facing you, the BDM points are on the right, matching EDC16 conventions. Use that orientation to place your BDM probe correctly and avoid pin swaps during reads. [Elektroda, MIKUr1, post #18477316]
After alternator replacement, AFS still dead—what sequence should I follow?
Confirm power per the BMW diagram, then attempt a software flash. If unsuccessful, read the MPC via BDM and repair the dump. As a last step, try a known-good module coded with your VIN to isolate hardware from software faults. [Elektroda, MIKUr1, post #16847163]
Is the highlighted power stage the motor driver or CPU supply?
A pro review in-thread dismissed the initially highlighted part as the culprit and did not suspect the CPU itself. Prioritize verifying the supply path, firmware integrity, and BGA connectivity before replacing power stages. [Elektroda, MIKUr1, post #16883262]
Any quick on-car checks before ECU surgery?
Yes. Check battery SOC, alternator output ripple, and all fuses. Measure Kl.30 at the AFS connector. If ISTA/DIS communicates, try a controlled reflash. Only then proceed to bench BDM read or BGA work. “If there is communication, try flashing first.” [Elektroda, seat21, post #16841852]
Sometimes the alternator overcharged, other times it didn't. I did not notice it right away, because the car never refused to obey due to the fact that the moments when it did not load and loaded smoothly and quickly intertwined. I noticed it only on the last route before the alternator was repaired, when all possible controls went out and I started the charging voltage check function on the meter. I was far from home, and the car, after restarting, drove as it should and everything went out, so I concluded that there is no need to "tow". I will add that AFS was working properly until the very end. In the backyard it was fired from the cables 2-3 times and a few meters to the garage it was already "remaining electricity" and again the disco on the clocks. From that moment it was not fired until the alternator was repaired. After assembling and firing, I noticed the symptoms and errors listed in the first post. Coming back to the topic, isn't the selected system sometimes responsible for powering the electric motor? Can the processor also power it? As I mentioned before, after playing with Inpa it looks more like a CPU problem. I absolutely do not question knowledge, especially since mine is definitely much lower, I'm just trying to do something like brainstorming and bring this dead man back to life together 
