Convertible models of the BMW E-Series and Mini R-Series generations are equipped with a module that protects the occupants during a “rollover” crash.
These modules can fail after disconnecting the battery or if the battery is discharged too deeply. There are also other known cases where the controller spontaneously malfunctions.
You can recognize the fault by the following error codes and an error on the dashboard:
- 9402 Internal error
- 9402 Rollover-protection controller: internal fault
Relevant part numbers:
- 9264926
- 9201128
- 9187933
- 9180627
- 9179400
- 9134734
- 6950640
- And more
The ROC is present in, among others:
- BMW 1 serie – E88
- BMW 3 serie – E93
- BMW 6 serie – E64
- Mini R-serie
What does the rollover controller do?
The rollover controller is part of the BMW and Mini’s safety system. The module is designed to protect occupants in the event of a rollover crash, i.e., if the car rolls over or is about to roll over. The rollover controller is a computer that uses sensors to measure the car’s motion and determine when a rollover is imminent. These include gyroscopes, which measure motion along the horizontal and vertical axes, and accelerometers, which measure the car’s acceleration.
If the rollover controller detects a rollover, several safety measures are activated. The exact measures depend on the sensors. For example, the seatbelts are tightened and the side and curtain airbags are deployed to protect the occupants from injury. The fuel system can also be deactivated to prevent a fire in the event of an impact.
The rollover controller is an important part of a BMW’s safety system and contributes to the protection of the occupants in the event of a rollover.
Enlist the help of Carware
Fault
Unfortunately, the ROC module sometimes fails. In that case, a fault will be visible on the dashboard or via the iDrive. You can also recognize the ROC fault by the following error code in the airbag module (ABG/ACSM): 9402 Rollover-protection controller: internal fault.
This error often occurs when the battery has been discharged or due to a voltage spike in the car’s onboard electrical system. This can corrupt the data on the chip (EEPROM). The computer then detects this error and displays an error code.
It’s important to have this checked as soon as possible. Otherwise, a rollover crash could be fatal!
References
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After replacing several parts on my BMW M140 with no success, the ECU turned out to be the culprit. After some online research, I found Hagenaar Carware, where I received excellent service. Jan quickly diagnosed the problem correctly. He clearly explained the problem and the costs. Clear communication, no surprises, and expert service. Highly recommended for anyone with electronic problems with their BMW or MINI.
My car has been parked since July 7th due to a malfunction in the electronic steering lock on my BMW E90.
Last year, the entire steering column was replaced, but after a few months, the same problem arose. No one could solve it, but after a long search online, I found Jan, and after a clear explanation and a potential solution, I regained hope.
Jan remotely—how?—really got my car running again and immediately wrote down all the malfunctions and error messages.
Jan is a hero! It's a shame you can only give 5 stars and not 10, otherwise he would have definitely earned them!
Last year, the entire steering column was replaced, but after a few months, the same problem arose. No one could solve it, but after a long search online, I found Jan, and after a clear explanation and a potential solution, I regained hope.
Jan remotely—how?—really got my car running again and immediately wrote down all the malfunctions and error messages.
Jan is a hero! It's a shame you can only give 5 stars and not 10, otherwise he would have definitely earned them!
I had a problem with the ROC module for my BMW. Jan neatly fixed all the error codes and reinstalled the module. A fantastic solution, instead of having a new and expensive module replaced at the garage. Jan communicates quickly and honestly about the options and any risks. He also provides immediate clarity about the costs. In short, I understand why all the reviews here are 5 stars, and this one adds another 5 stars!
Response from the owner 06:46 01 Sep 25
Jos, dank voor je leuke review en je lovende woorden. Daar doen we het voor! 🙂
The ECM of a 320 convertible was repaired and updated with new software. The car now drives smoothly and better than ever. Excellent service! Perfect! Highly recommended!
Response from the owner 06:46 01 Sep 25
Dank voor je lovende woorden!
I have an old BMW Z3, and after winter storage, it wouldn't start.
Jan was able to come on-site within two days to scan the Z3, but unfortunately, that wasn't possible because the Z3 has an older system.
Luckily, Jan still had an old laptop with the correct software.
He quickly realized the AWS module was malfunctioning. He gave me tips on how to work around this and adjusted the ECU. And yes, it's running like a charm again.
Excellent, clear communication, good advice.
Simply a true professional.
We need more of them.
Jan was able to come on-site within two days to scan the Z3, but unfortunately, that wasn't possible because the Z3 has an older system.
Luckily, Jan still had an old laptop with the correct software.
He quickly realized the AWS module was malfunctioning. He gave me tips on how to work around this and adjusted the ECU. And yes, it's running like a charm again.
Excellent, clear communication, good advice.
Simply a true professional.
We need more of them.
Response from the owner 06:47 01 Sep 25
Joost, dank voor je leuke review. En veel rijplezier toegewenst in je Z3!
My frame broke.
He expertly repaired it for me.
Great service.
I was able to get an appointment within two hours and it was fixed within half an hour. Absolutely fantastic.
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He expertly repaired it for me.
Great service.
I was able to get an appointment within two hours and it was fixed within half an hour. Absolutely fantastic.
Highly recommended 👌👌
Response from the owner 09:57 28 Jul 25
Dankjewel Cristian voor je review. En fijn dat je FRM het weer helemaal doet
We had Jan install original BMW cruise control in our BMW Z4. Everything was expertly installed and thoroughly tested. Jan works calmly and consistently. Highly recommended!
Response from the owner 09:58 28 Jul 25
Ha Johan,Fijn dat je blij bent met de originele cruise control. Origineel blijft in onze ogen de mooiste oplossing voor je Z4.Hartelijke groet,Carware
After some online research, I found Hagenaar Carware for an upgrade to the DCT gearbox in my BMW E92 M3, specifically the GTS software. After contacting them through the app, I was able to quickly schedule an appointment.
Once I arrived, Jan already heard me 🥳. He immediately grabbed the laptop to check everything for error codes, after which the software could be installed. Meanwhile, Jan changed my menu to Dutch (it was in English), completely free of charge 👌
After an hour, we were back on the road, and the shifting was so incredibly fast.
Thanks, Jan!
Once I arrived, Jan already heard me 🥳. He immediately grabbed the laptop to check everything for error codes, after which the software could be installed. Meanwhile, Jan changed my menu to Dutch (it was in English), completely free of charge 👌
After an hour, we were back on the road, and the shifting was so incredibly fast.
Thanks, Jan!
Response from the owner 09:59 28 Jul 25
Ha Piet,Het werken aan een E92 M3 is altijd extra leuk. Fijn dat je tevreden bent, en het mooie V8-geluid was inderdaad al van ver te herkennen ;-)Hartelijke groet,CarwareTroubleshooting
There are two ways to resolve this issue. First, the module can be replaced with a new one, which is the most expensive solution. Fortunately, it’s also possible to repair the module.
During the repair, the chip is read, the data is recovered, and then the chip is rewritten. This is done using specialized programming equipment. After this, the module will function normally again. There’s always a very small chance that the module actually has a hardware defect; in that case, the memory may become corrupted again after the repair. Normally, the problem is permanently resolved.
Note!
Unfortunately, there are also companies that can (cheaply) write off this error. This is extremely dangerous; absolutely do not try this!
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