BigSud
2nd March 2025, 10:19 AM
Hi all,
This is my first "proper" post - seeking insight into a weird problem - although a couple of years back I sought advice on changing my SDV6 inlet manifolds. To the excellent advice I found for that job, I would add "buy crows-foot spanners".
This particular query is the first of three, the others of which I'll get to once I've solved the screen/battery issue, but in the interests of good storytelling they are:
1) Infotainment screen dead, 1.2A drain
2) Preventive maintenance main & big-end bearing replacement on the SDV6?
3) Which motor would be the best upgrade if there is a lot of towing in our future (there is) - a TDV8 (which one?) or should we wait and see about the "new" Ranger V6?
Some history of the car, which we intend to keep for another 10 years at least. Ours is a 2015 NZ-new Discovery 4 HSE SDV6 with the factory Safari and Winter packs fitted, meaning - as far as I can ascertain - it has the big alloy bash guard on the front, a snorkel and driving lights, plus heated steering wheel and side mirrors, plus the rear climate control. We're the second owners, having bought it in 2017 with 103 km on it, just out of warranty. It's now covered 233 km, until recently fairly reliably. The only issues have been the handbrake module (replaced under extended warranty) and the inlet manifolds. 103 km in 2 years is a LOT of driving, which we think were "hot miles" with relatively fewer cold starts than you'd need to see that mileage over five or ten years.
Last year, at about 130,000 km, the HP fuel pump let go. Because we were 500 km from home, we had little choice but for the AA to take it to a local European specialist. They did the diagnosis, lifted the body, and replaced the HPFP. The car fought them every step of the way, but eventually all was fixed and it was running well. In hindsight - such a useful thing - I would have had it freighted home and invested in a two-post hoist and did the job myself.
When I picked it up, the infotainment screen wasn't working - although the digitiser still was as it beeped when pressed. They checked the fuses and nothing was amiss, and said it had never been working for them. I accepted it because after months of waiting, plus travel to get it - I just wanted it back and could sort out a dead screen later. Maybe it's a good excuse to do one of those CarPlay upgrades [smilebigeye]
The next morning, the battery didn't have enough juice to start the car. AA arrived, declared that 10 years was a good run out of the original battery, so I bought another AGM matching the original JLR one. Next morning it started OK. But three days later it didn't.
Fast forward to now, a few months later. It's had two "failed to proceed" incidents, both related to the power supply to the LPFP, so I've both replaced the LPFP itself AND bypassed the entire feed from the fusebox as somewhere in one of the three connectors along the way it was losing voltage. Such things often happen when something is disturbed by a major effort like removing the body - I've seen it with other cars we've owned - and there are some silly details on the D4 that don't help with that.
But to come back onto the main topic of the thread, I think that in the process of removing and replacing, then removing again (don't ask) and replacing the body to get the engine to fire something has been fried in either the infotainment screen or the amp that feeds it. I've found the circuit that's draining the battery, and its Fuse 1 (in the upper passenger compartment fuse box) for the screen. It drains up to 1.2 A with the ignition off and the car asleep. With the screen unplugged, the drain stops. Using a MOST bypass loop on the screen does not affect the drain. Substituting an apparently good used screen does not affect the drain.
Apart from the screen not working, up until recently almost everything else WAS working.. The Bluetooth audio, which is the only audio we ever use - was still functioning, right up until I ran my phone over and had to pair the new one. Which is impossible when the screen doesn't work. The radio still works and the amplifier still...amplifies. The audio-related steering wheel controls do not work.
My current theory is that some capacitor or MOSFET in the amp has been fried by the body off/on/off/on palaver, and its not allowing the screen to turn off - nor is feeding it anything. Question 1 - does this seem plausible?
So I stripped out everything again to get a look at the label on the amp - see the pic below.
192705
There are LOADS of these available on eBay, and they seem to all differ in the last two letters of the version number - in my case CF6N-18C815 - MK. I'm assuming that that this is some sort of model/country signifier, but further I'm assuming that unless I want the (useless) SatNav and (boring) radio functions to work, swapping in a functional one of these might solve the battery drain problem AND restore the screen function. Question 2 - am I right here?
As far as I can tell, the Holder Of The Knowledge is Old Jaguar - AND it seems he also knows about engine swaps. Would that be right?
Question 3 - what have I missed?
I'm not a fan of the Parts Cannon, so if there's a known problem that twenty minutes with the soldering iron and a DVM could fix, that's much better for all concerned.
Thanks for reading this far. I'll set myself up a signature soon. For now, this is my fifth Land Rover - an RRC, 2 x P38s (all gone) and I currently have a 1954 S1 86" which is an atmospheric corrosion experiment. Which is fitting because I used to be a corrosion scientist. That makes the three additional Alfa Romeos cluttering up the place particularly ironic doesn't it?
Chris
In Kapiti, New Zealand.
This is my first "proper" post - seeking insight into a weird problem - although a couple of years back I sought advice on changing my SDV6 inlet manifolds. To the excellent advice I found for that job, I would add "buy crows-foot spanners".
This particular query is the first of three, the others of which I'll get to once I've solved the screen/battery issue, but in the interests of good storytelling they are:
1) Infotainment screen dead, 1.2A drain
2) Preventive maintenance main & big-end bearing replacement on the SDV6?
3) Which motor would be the best upgrade if there is a lot of towing in our future (there is) - a TDV8 (which one?) or should we wait and see about the "new" Ranger V6?
Some history of the car, which we intend to keep for another 10 years at least. Ours is a 2015 NZ-new Discovery 4 HSE SDV6 with the factory Safari and Winter packs fitted, meaning - as far as I can ascertain - it has the big alloy bash guard on the front, a snorkel and driving lights, plus heated steering wheel and side mirrors, plus the rear climate control. We're the second owners, having bought it in 2017 with 103 km on it, just out of warranty. It's now covered 233 km, until recently fairly reliably. The only issues have been the handbrake module (replaced under extended warranty) and the inlet manifolds. 103 km in 2 years is a LOT of driving, which we think were "hot miles" with relatively fewer cold starts than you'd need to see that mileage over five or ten years.
Last year, at about 130,000 km, the HP fuel pump let go. Because we were 500 km from home, we had little choice but for the AA to take it to a local European specialist. They did the diagnosis, lifted the body, and replaced the HPFP. The car fought them every step of the way, but eventually all was fixed and it was running well. In hindsight - such a useful thing - I would have had it freighted home and invested in a two-post hoist and did the job myself.
When I picked it up, the infotainment screen wasn't working - although the digitiser still was as it beeped when pressed. They checked the fuses and nothing was amiss, and said it had never been working for them. I accepted it because after months of waiting, plus travel to get it - I just wanted it back and could sort out a dead screen later. Maybe it's a good excuse to do one of those CarPlay upgrades [smilebigeye]
The next morning, the battery didn't have enough juice to start the car. AA arrived, declared that 10 years was a good run out of the original battery, so I bought another AGM matching the original JLR one. Next morning it started OK. But three days later it didn't.
Fast forward to now, a few months later. It's had two "failed to proceed" incidents, both related to the power supply to the LPFP, so I've both replaced the LPFP itself AND bypassed the entire feed from the fusebox as somewhere in one of the three connectors along the way it was losing voltage. Such things often happen when something is disturbed by a major effort like removing the body - I've seen it with other cars we've owned - and there are some silly details on the D4 that don't help with that.
But to come back onto the main topic of the thread, I think that in the process of removing and replacing, then removing again (don't ask) and replacing the body to get the engine to fire something has been fried in either the infotainment screen or the amp that feeds it. I've found the circuit that's draining the battery, and its Fuse 1 (in the upper passenger compartment fuse box) for the screen. It drains up to 1.2 A with the ignition off and the car asleep. With the screen unplugged, the drain stops. Using a MOST bypass loop on the screen does not affect the drain. Substituting an apparently good used screen does not affect the drain.
Apart from the screen not working, up until recently almost everything else WAS working.. The Bluetooth audio, which is the only audio we ever use - was still functioning, right up until I ran my phone over and had to pair the new one. Which is impossible when the screen doesn't work. The radio still works and the amplifier still...amplifies. The audio-related steering wheel controls do not work.
My current theory is that some capacitor or MOSFET in the amp has been fried by the body off/on/off/on palaver, and its not allowing the screen to turn off - nor is feeding it anything. Question 1 - does this seem plausible?
So I stripped out everything again to get a look at the label on the amp - see the pic below.
192705
There are LOADS of these available on eBay, and they seem to all differ in the last two letters of the version number - in my case CF6N-18C815 - MK. I'm assuming that that this is some sort of model/country signifier, but further I'm assuming that unless I want the (useless) SatNav and (boring) radio functions to work, swapping in a functional one of these might solve the battery drain problem AND restore the screen function. Question 2 - am I right here?
As far as I can tell, the Holder Of The Knowledge is Old Jaguar - AND it seems he also knows about engine swaps. Would that be right?
Question 3 - what have I missed?
I'm not a fan of the Parts Cannon, so if there's a known problem that twenty minutes with the soldering iron and a DVM could fix, that's much better for all concerned.
Thanks for reading this far. I'll set myself up a signature soon. For now, this is my fifth Land Rover - an RRC, 2 x P38s (all gone) and I currently have a 1954 S1 86" which is an atmospheric corrosion experiment. Which is fitting because I used to be a corrosion scientist. That makes the three additional Alfa Romeos cluttering up the place particularly ironic doesn't it?
Chris
In Kapiti, New Zealand.