Defender Hybrid's Mystery: Grinding Gears & Warning Signs

Hey there! I had a similar issue with my 2019 Discovery Hybrid (also owned a Range Rover previously). As someone with moderate experience working on cars, those symptoms sound very familiar. Had the exact same problems, gear slipping, grinding noise during shifts, and warning lights. Took it to my trusted workshop, and it turned out the transmission oil level was dangerously low. They did a complete transmission fluid check and refill, which set me back about 365 Euro, but it fixed everything perfectly. Before you jump to conclusions about the sensor though, could you share: How many miles/km on your Defender? When was the last transmission service? Is the grinding noise constant or only when cold? This info would help me give you more specific advice about whether you're dealing with the same issue I had. Always better to rule out the simple stuff first!

Thanks for sharing your experience! My Defender has 67620 KM on the clock and just had its service last month. The grinding noise actually only happens when shifting gears, especially between 2nd and 3rd, but it's definitely more noticeable when the engine is cold. The slipping seems unusual though, sometimes it's fine for hours, then suddenly acts up. Really appreciate the tip about the transmission fluid, that's definitely less scary than a sensor issue! I'll get it checked out asap. Did you notice any other warning signs before your fluid got low? Just trying to figure out if I might have missed some earlier red flags.

Hey again! Thanks for the follow-up. Given what you've shared about the mileage and service history, I think we might be looking at something different than what I experienced with my Discovery. Mine started acting up around 45000 KM, and the symptoms were pretty consistent rather than intermittent like yours. The cold-start grinding between 2nd and 3rd is particularly interesting, that's exactly how mine started before the unusual slipping kicked in. But here's the thing: when my transmission fluid was low, the problems were constant, not intermittent like yours. After doing some more digging on Land Rover forums and from my own experience, I'm actually leaning towards your initial suspicion about the sensor. In my case, after the fluid change didn't completely solve the issue, it turned out I did have a faulty transmission control module that was misreading the pressure signals. The intermittent nature of your problem matches this more closely than a straight fluid issue. Quick question, have you noticed any lag or hesitation when you first accelerate from a stop? This was another symptom I experienced that helped diagnose the actual problem. If you're experiencing this too, I'd definitely recommend getting the sensor checked out.

I'll complete it from's perspective: Thanks for that detailed insight! That's really helpful, especially about the transmission control module, it actually makes a lot more sense now. And yes, I've definitely noticed that lag you mentioned when starting from a stop! I hadn't connected the dots between that and the other issues. You know what's funny? I was so focused on the grinding noise that I almost missed mentioning the hesitation at stops, but now that you bring it up, it's been happening pretty consistently for the past few weeks. Think I'll get both the sensor and the module checked out rather than just assuming it's a fluid issue. Better safe than sorry with these complex hybrids, right? Really appreciate you taking the time to walk me through your experience. Definitely feeling more confident about heading to the mechanic now with a clearer idea of what might be wrong. Will update the group once I get it sorted!