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Powertrain Malfunction / Reduced Power on 2020 Cobra GT 500

atxcobra

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I recently purchased a 2020 Cobra GT 500 and was enjoying it quite a bit. This past weekend during a drive with one of my kids, I started to accelerate from a light, and suddenly the car started jerking back and forth, as if it couldn't properly shift. Then, the orange wrench icon appeared on the dash, and I received an error warning titled "Powertrain Malfunction / Reduced Power" on the Fordpass App. I was able to slow down and pull off onto a side street. I resumed driving, but without accelerating very quickly, to see if the car would shift properly without accelerating faster, and it did. Then, I got a second error, titled "Malfunction Indicator Lamp - Regulatory".

Naturally, this is a major disappointment, since the car has only 255 miles on it, newly purchased within the last month. The dealer sent out a flatbed tow truck to my location, to bring the car in for assessment. The dealership has been in touch with Ford engineering, and together they were able to trace the issue to an open circuit in the harness going to the transmission. They're confident it's not an issue with the transmission, but likely just a faulty pin, or worst case, the whole harness. I will say, the dealer has been awesome during this experience, and they're doing a great job at keeping me updated. That said, this is really surprising to have happen on a brand new car, and concerns me about what else may going to "go wrong" on the vehicle.

I'll post an update once I get the car back, but I'm curious how many other folks have had this happen?

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Cobra Jet

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I recently purchased a 2020 Cobra GT 500 and was enjoying it quite a bit. This past weekend during a drive with one of my kids, I started to accelerate from a light, and suddenly the car started jerking back and forth, as if it couldn't properly shift. Then, the orange wrench icon appeared on the dash, and I received an error warning titled "Powertrain Malfunction / Reduced Power" on the Fordpass App. I was able to slow down and pull off onto a side street. I resumed driving, but without accelerating very quickly, to see if the car would shift properly without accelerating faster, and it did. Then, I got a second error, titled "Malfunction Indicator Lamp - Regulatory".

Naturally, this is a major disappointment, since the car has only 255 miles on it, newly purchased within the last month. The dealer sent out a flatbed tow truck to my location, to bring the car in for assessment. The dealership has been in touch with Ford engineering, and together they were able to trace the issue to an open circuit in the harness going to the transmission. They're confident it's not an issue with the transmission, but likely just a faulty pin, or worst case, the whole harness. I will say, the dealer has been awesome during this experience, and they're doing a great job at keeping me updated. That said, this is really surprising to have happen on a brand new car, and concerns me about what else may going to "go wrong" on the vehicle.

I'll post an update once I get the car back, but I'm curious how many other folks have had this happen?

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The issue is common enough that Ford has issued an SSM on it. How many GT500’s are affected is an unknown. Most likely this is what your Service Center and Ford Engineering are researching.

See this thread for more info:
https://www.mustang6g.com/forums/th...r-multi-dtc’s-related-to-transmission.156359/
 
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atxcobra

atxcobra

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The issue is common enough that Ford has issued an SSM on it. How many GT500’s are affected is an unknown. Most likely this is what your Service Center and Ford Engineering are researching.

See this thread for more info:
https://www.mustang6g.com/forums/th...r-multi-dtc’s-related-to-transmission.156359/
Thank you so much for sharing. I had searched for other threads, and found one, but it was an older model Mustang. This is super helpful, and something I'm going to reach out to the dealer about tomorrow. This sounds like exactly what they are looking into, as they told me that they plan to get the transmission out and address the harness issue with a fix or replacement.

Thanks again for sharing!
 

Cobra Jet

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Thank you so much for sharing. I had searched for other threads, and found one, but it was an older model Mustang. This is super helpful, and something I'm going to reach out to the dealer about tomorrow. This sounds like exactly what they are looking into, as they told me that they plan to get the transmission out and address the harness issue with a fix or replacement.

Thanks again for sharing!
No problem Adam; that’s what we are here for, helping each other out. Stick around, this site has a lot of great folks and tons of great tech. The GT500 sub forum on here is great too - lots of GT500 owners with a wealth of knowledge too.
 
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atxcobra

atxcobra

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Update: The dealer has had the car for 10 days now, and it still isn't fixed. They diagnosed the issue with Ford engineering, and Ford told them to replace the entire harness, not just a pin or a piece. The dealer removed the transmission, replaced the harness, and ... it's still not working. Different error codes this time, and now the car won't move out of 'Park' into gear. The dealer is now saying that Ford told them to "try another harness". So, it's going to be another period of time to wait for the harness to get shipped, transmission removed, part replaced, and see what happens. I had the car for 4 weeks before they took it, and now it will have been in the shop for 3 weeks. Any chance I should be concerned that this isn't just a part, and that the car is a lemon? Interested in any thoughts and/or advice.
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