RR Sport L494 - Hybrid Cooling fault after engine rebuild

Hi all,

I have a RR Sport L494 2020 Petrol Hybrid 2.0 with 50k miles which just had an engine rebuild. Engine now back in car but is now showing the following fault.
P0A93-92 Inverter A Cooling system performance - Performance or incorrect operation.

After about 1 minute driving the car throws up this fault and puts the car into limp mode.

This fault was not there prior to the engine being taken out. A brand new coolant pump has been fitted but still no luck and the system has been bled thoroughly. I am at my wits end in how to fix this. Does anyone here have any experience with Hybrid issues after an engine rebuild on one of these? I would be so grateful for any advice.

Thanks

Peter

Land Rover barely pulled off building a working petrol vehicle. I can only imagine how messed up one of their hybrid attempts can be.

Yikes.

This may be a learning curve for most of us here!!
Who has done the work on the RR?

There are two distinctly separate cooling systems for a hybrid vehicle, the process for filling & bleeding needs to be followed precisely and involves the use of vacuum filling equipment and JLR diagnostic software to open the relevant diverter valves and run the coolant pumps.
The DTC you list is caused by a coolant pump running too fast or drawing too little current, the inferred cause is air in the inverter cooling circuit, this would / should have been picked up when the system was refilled with the 'confirmation' routine that is run as part of the bleed procedure.
Whilst you can drain, fill & bleed the engine circuits relatively easily, the hybrid circuits do need special attention and can result in expensive consequential damage if not done correctly.

Graculus said:

There are two distinctly separate cooling systems for a hybrid vehicle, the process for filling & bleeding needs to be followed precisely and involves the use of vacuum filling equipment and JLR diagnostic software to open the relevant diverter valves and run the coolant pumps.
The DTC you list is caused by a coolant pump running too fast or drawing too little current, the inferred cause is air in the inverter cooling circuit, this would / should have been picked up when the system was refilled with the 'confirmation' routine that is run as part of the bleed procedure.
Whilst you can drain, fill & bleed the engine circuits relatively easily, the hybrid circuits do need special attention and can result in expensive consequential damage if not done correctly.

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It's good that there is someone who knows about this modern stuff

Great advice Graculus, I will definitely pass onto my mechanic.

I use an independent garage due to not having good experiences with the main dealer. The final straw for me was when I was in the Land Rover service department collecting my car after having some warranty work done and the service manager came out of the back room and had the following conversation with a customer waiting on the next table.

Dealer - "We have done multiple diagnostics, replaced the battery, wiring loom, fuel pump and we are still unable to start the car, we have no idea what it could be"

Customer - "So what do you suggest I do?"

Dealer - At this point we advise you sell it for parts.

Customer - "I'm not selling a car I bought 2 years ago from you for parts!!!"

I promptly collected my key and left.

Marshalls Land Rover Cambridge.

pidda123 said:

Great advice Graculus, I will definitely pass onto my mechanic.

I use an independent garage due to not having good experiences with the main dealer. The final straw for me was when I was in the Land Rover service department collecting my car after having some warranty work done and the service manager came out of the back room and had the following conversation with a customer waiting on the next table.

Dealer - "We have done multiple diagnostics, replaced the battery, wiring loom, fuel pump and we are still unable to start the car, we have no idea what it could be"

Customer - "So what do you suggest I do?"

Dealer - At this point we advise you sell it for parts.

Customer - "I'm not selling a car I bought 2 years ago from you for parts!!!"

I promptly collected my key and left.

Marshalls Land Rover Cambridge.

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Blimey, the sticker in my P38's Back window says "Marshalls of Cambridge". How comforting to hear.

Datatek said:

It's good that there is someone who knows about this modern stuff

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Its my day job, just not JLR's (for now).

Graculus said:

Its my day job, just not JLR's (for now).

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You will be needed more and more as us oldies with P38's fade away. Despite working in electronics and racing club level cars, I wont go near the new stuff.

I'm no spring chicken either! I would say how many years off retirement I am, but that's a 'moveable feast'...
You'll no doubt have noticed I stay away form the older stuff, sometimes because it's genuinely too long ago for me to recall details and sometimes, 'too many cooks spoil the broth'. Working with current vehicle tech on a daily basis does help, but I think there has to be a genuine (as opposed to 'I need to know this to do my job') interest, and of course, owning a later LR does focus the mind!

DanClarke said:

Blimey, the sticker in my P38's Back window says "Marshalls of Cambridge". How comforting to hear.

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I am sure i have read their name many times over the years, none of them in a good context!