Hi everyone,
I’m driving a 2008 Range Rover Sport TDV8 (L320) and have been struggling with a strange electrical issue for a few weeks now. I’m hoping someone here has experienced something similar or can help me narrow it down.

Note: If there are any existing threads on this topic, I’d be very grateful for a link. I’ve tried searching the forum, but since English is not my first language, I found it difficult to verify whether the entries match my situation.

Timeline of Symptoms:
1. First occurrence (about 3 weeks ago):
• Ignition on → only dashes in the instrument cluster, no temperature or time shown
• Message displayed: “System control in progress”
• Turning the key → nothing happens, engine won’t start
• Suspension fault message: “Suspension fault. Vehicle may lean when cornering” (Aufhängungsfehl.
Fahrzeugneig in Kurven)
• Battery measured at 11.9 V
• Charged overnight to 12.9 V → same issue
• Replaced the battery → vehicle started normally, all errors gone (for about 10 days)

2. Intermittent failures:
• After 5–10 minutes of driving:
• Beep + suspension warning Suspension fault. Vehicle may lean when cornering” (Aufhängungsfehl.
Fahrzeugneig in Kurven)
• Complete failure of dash, lights, radio, nav, windows
• Engine keeps running
• After 2–3 minutes: system reboots, most functions return
• Yellow suspension warning light stays on (aufhängungswarnleuchte)
• Next ignition cycle → everything back to normal
• This behavior repeats randomly
• When the system fails, the radio displays: “Vehicle Fault – System Shutting Down”
• Also: hazard lights activate automatically without touching the switch (possible safety function?)

Technical checks:
• New battery: 12.98 V resting voltage
• Alternator charging: 13.75 V at idle
• Voltage drop between battery and engine block: 0.021 V
• Front 12V socket shows burn marks inside, but fuse is intact
• Audible clicking under driver’s seat after failure

Known issues & work done:
• Driver’s door latch faulty (replacement ordered)
• Front sway bar bushes worn
• Slight leak on rear stabilizer, hydraulic fluid was at minimum
• 12V socket confirmed damaged – removed (USB-C version ordered)
Work already done:
• Replaced battery
• Checked grounding points in engine bay
• Removed CJB (Central Junction Box), found and re-soldered several cold solder joints
→ Door latch worked immediately after
• Cleaned ground near A-pillar in passenger footwell
• Reinstalled CJB, cleared all error codes → system worked fine for 3 days
• On day 4: issue returned exactly as before

Questions to the community:
• Has anyone ever experienced such a chain reaction of electrical failures?
• Could a faulty 12V socket or internal short really crash the CAN bus or body systems?
• Are there additional ground points or harness connectors in the cabin or trunk I should inspect?

Any help or advice would be very much appreciated.
This car is a joy to drive… when it works. 😅
Best regards,
Eki

Hi V8Alpinist,

I had a similar issue on my TDV8 back in 2017 and posted on here and the advice was brill sorted my issues out. I ended up changing the brake light switch at the back of the brake peddle and also the hand brake switch on the center console and all the faults cleared. The topic is under the heading Christmas tree lights it might help. As a side note i originally purchased a cheaper after market brake light switch which failed again after about 18 months. i then purchased a genuine one from Rimmer bros and have no issues since.

Hi, thanks a lot for the tip – I’ll definitely check that next!

By the way, I’ve noticed that my battery seems to drain down quite fast, often resting at around 12.1 V after the car has been parked for a while.
Did you experience the same kind of battery drain during your troubleshooting?

Thanks again – much appreciated!
– V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style

Hi

I did't notice any battery drain when i checked mine with it running it was outputting about 14.3volts and when off between 12.6 to 12.7volts. Mine can sit for a few weeks between use i haven't noticed any issues with starting so i assume the battery has enough power starts first turn of the key.

Cheers Ade

Hi all,

My never-ending RRS story continues – and I’m hoping for some insights from the community. Maybe someone has seen similar symptoms.

🔧 What’s been done so far:
Checked all ground points in the vehicle and at the battery

Removed and re-soldered the CJB (Central Junction Box) due to cold solder joints

Removed the 12V socket (had visible burn marks)

📉 Current issue:
I noticed the air suspension compressor runs excessively long, even after the target height is reached.
→ It gets very hot
→ The car displays: “Suspension raising slowly”

I performed a leak test with soapy water on all connections – no leaks found.

🛠️ Workshop visit & professional diagnostics:
I had the car checked at a Range Rover specialist using professional diagnostic tools.
Result: multiple communication faults between ECUs

Their suspicion:
→ Possibly a faulty control module behind the battery (potential water ingress?)

Back home, I removed the battery and inspected all connectors – no signs of moisture, no corrosion, everything dry.

🧪 Fault codes from iCarsoft LR V3.0:
RLM: U0416-86

ATCM: U0416-94

VDM: U0128-87, C1A00-88

Side note: My iCarsoft V3.0 often causes HDC faults / “Special Programs Off” as soon as I initiate a diagnostic session, which makes troubleshooting even harder.

🚘 Interestingly:
I drove over 100 km today – city, highway, country roads – and no errors showed up during the whole trip. The car performed perfectly.

❓ Questions:
Has anyone experienced similar behaviour?

Is anyone using the iCarsoft LR V3.0 with the L320 and noticing communication problems, especially with VDM or the ACE module?

Thanks in advance for any ideas or suggestions!

Cheers,
V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style

Hi all,

My never-ending RRS story continues – and I’m hoping for some insights from the community. Maybe someone has seen similar symptoms.

🔧 What’s been done so far:
Checked all ground points in the vehicle and at the battery

Removed and re-soldered the CJB (Central Junction Box) due to cold solder joints

Removed the 12V socket (had visible burn marks)

📉 Current issue:
I noticed the air suspension compressor runs excessively long, even after the target height is reached.
→ It gets very hot
→ The car displays: “Suspension raising slowly”

I performed a leak test with soapy water on all connections – no leaks found.

🛠️ Workshop visit & professional diagnostics:
I had the car checked at a Range Rover specialist using professional diagnostic tools.
Result: multiple communication faults between ECUs

Their suspicion:
→ Possibly a faulty control module behind the battery (potential water ingress?)

Back home, I removed the battery and inspected all connectors – no signs of moisture, no corrosion, everything dry.

🧪 Fault codes from iCarsoft LR V3.0:
RLM: U0416-86

ATCM: U0416-94

VDM: U0128-87, C1A00-88

Side note: My iCarsoft V3.0 often causes HDC faults / “Special Programs Off” as soon as I initiate a diagnostic session, which makes troubleshooting even harder.

🚘 Interestingly:
I drove over 100 km today – city, highway, country roads – and no errors showed up during the whole trip. The car performed perfectly.

❓ Questions:
Has anyone experienced similar behaviour?

Is anyone using the iCarsoft LR V3.0 with the L320 and noticing communication problems, especially with VDM or the ACE module?

Thanks in advance for any ideas or suggestions!

Cheers,
V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style

Hi all,

My never-ending RRS story continues – and I’m hoping for some insights from the community. Maybe someone has seen similar symptoms.

🔧 What’s been done so far:
Checked all ground points in the vehicle and at the battery

Removed and re-soldered the CJB (Central Junction Box) due to cold solder joints

Removed the 12V socket (had visible burn marks)

📉 Current issue:
I noticed the air suspension compressor runs excessively long, even after the target height is reached.
→ It gets very hot
→ The car displays: “Suspension raising slowly”

I performed a leak test with soapy water on all connections – no leaks found.

🛠️ Workshop visit & professional diagnostics:
I had the car checked at a Range Rover specialist using professional diagnostic tools.
Result: multiple communication faults between ECUs

Their suspicion:
→ Possibly a faulty control module behind the battery (potential water ingress?)

Back home, I removed the battery and inspected all connectors – no signs of moisture, no corrosion, everything dry.

🧪 Fault codes from iCarsoft LR V3.0:
RLM: U0416-86

ATCM: U0416-94

VDM: U0128-87, C1A00-88

Side note: My iCarsoft V3.0 often causes HDC faults / “Special Programs Off” as soon as I initiate a diagnostic session, which makes troubleshooting even harder.

🚘 Interestingly:
I drove over 100 km today – city, highway, country roads – and no errors showed up during the whole trip. The car performed perfectly.

❓ Questions:
Has anyone experienced similar behaviour?

Is anyone using the iCarsoft LR V3.0 with the L320 and noticing communication problems, especially with VDM or the ACE module?

Thanks in advance for any ideas or suggestions!

Cheers,
V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style

Hi,

I have the iCarsoft v3 reader and it too says HDC fault when I run a diagnostic. But it doesn't affect the reading.

As soon as you unplug the warning goes away.

Clear all the fault codes and run the scan again, you don't get fault codes. So I assume it's just a quirk of the reader. L320 Range Rover Sport 2008
3.6 TDV8

Suspension.

https://www.autodoc.co.uk/hitachi/13965231

If you wait long enough I got mine for £350
Changed it which is easy enough and no more over heating and raising slowly warnings. L320 Range Rover Sport 2008
3.6 TDV8

Thanks for your reply – that’s very helpful to know!

In my case, the behaviour seems very similar: as soon as I start the scan, the HDC fault appears, but once I unplug the device and cycle the ignition, it clears.

I can clear the fault codes, but they do come back again afterwards — so I guess I have to assume that those are real faults, not just caused by the scanner.

Good to know the HDC fault itself is likely just a quirk of the device!

Thanks again.
– V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style

Thanks for the link and the info – much appreciated!

I had the car checked by a Range Rover mechanic, and his opinion is that it’s probably not an issue with the compressor itself.
He suspects the problem is more related to communication errors between the ECUs, rather than a mechanical fault.

So for now I’ll keep investigating on that side before replacing the compressor – but your experience is very good to know, in case I do need to go that way later!

Thanks again.
– V8Alpinist RR Sport TDV8 & Evoque Si4 | I can’t afford more, but at least I break down in style