An E60 M5 and the Red Cog of Death

An E60 M5 and the Red Cog of Death

Are you worried about a transmission fault light on your dash and are looking for an auto mechanic for to check if your BMW has the dreaded “red cog of death”? Fluid MotorUnion in Naperville is the auto repair shop that has experience in replacing BMW clutches and complete diagnostics of the SMG transmission in BMW’s, as well as any service or repair work you may need. When your BMW has the transmission fault message, aka the “Red Cog of Death” in your SMG-equipped BMW, you need to get your car to a service facility ASAP … if you can even get the car to drive, that is! For one customer, the Red Cog of Death struck at a bad time, but with our auto mechanics expert knowledge and abilities, he’s back on the road in fighting form.



Recently, a customer sent us an e-mail detailing a new issue with his SMG-equipped E60 M5. While driving in first gear, the Red Cog of Death appeared, but it went away after he shifted. Two stop signs later, the car stalled out, and it could not be restarted. The gear position on the dashboard showed Neutral, but nothing could get the car started. This was after a random check engine light appeared earlier in the week, but it went away on its own.

Once he had the car towed to us, we put the M5 up on the rack to see if we could locate the cause of this issue. Sure enough, after we got a peek at the underside, we noticed what was wrong. The wires you see above are all frayed, and that’s not a good thing at all; those are the wires for the gear-position sensor, so the car didn’t actually know what gear it was in. Hence the inability to restart. Unfortunately, when these wires fray, you can’t just replace the wires; instead, you need to replace the entire pump.

Thankfully, the customer had already intended to replace the entire SMG pump assembly, in order to reinforce the SMG against any sort of future problems. He was also intent on replacing other pieces of the SMG, so that he had a perfectly-functioning transmission that acted and felt brand new. So, along with the SMG pump, we replaced the clutch, flywheel, PLCD sensor, throwout bearing, SMG fluid, and other components.







As we’ve said in the past, it’s best to get multiple jobs done at once if they are all centered around a specific region of the vehicle. That way, you save money on labor, because the transmission will only need to be dropped once (rather than twice or thrice, depending on how long you put off the forthcoming repair work). Plus, there’s no feeling quite as nice as having a whole slew of components replaced at once. The car feels like it’s brand new again.

Is your BMW displaying the red cog of death transmission fault and are looking for an auto mechanic to help you figure out whats going on? Fluid MotorUnion has all of the experience and diagnostic equipment to make sure your BMW’s transmission system is working properly. If you have questions about the transmission on your vehicle, don’t hesitate to get in touch with us via phone at 630-305-3054, or contact us through email at We’re conveniently located at the Iron Gate Motor Plaza in Naperville, just minutes from the I88 Rt. 59 exit, right next to top golf!

  • James
    Posted at 13:28h, 11 September

    How many miles does the M5 have when the “red cog of death” commonly occurs, and how many miles did this example have?

  • Grazyna
    Posted at 10:52h, 13 September

    Very good article. I definitely love this site. Keep writing!

  • fluidmotorunion
    Posted at 13:22h, 15 September

    SMG issues seem to be more age/time related than mileage traveled. That being said, this one had 70k miles plus.

  • Giray
    Posted at 19:26h, 21 April

    Same thing happened to me. So whole thing has to replaced ?

  • fluidmotorunion
    Posted at 14:37h, 09 May

    depends on how it broke, but yes typically, as they still don’t sell the sensor separately.

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