Soooooo, i got to the train station en route to buying the car to read all your doom and gloom....but clearly wise advice. And already you're correct in that i can't find a thing online about these engines or the drivetrain.

But yes, against your better judgement i ended up buying it - partly because i was desperate to get b@lls-deep in a L494 (and it was dirt cheap) and partly out of curiosity for it. It also has great main dealer history (7 stamps up to 60K miles) and the suspension was rock solid. No real error codes before or after the test drive so went for it.

First impressions are that i don't know how they get so much space around the engine! i can reach down and touch the broken gator on the steering UJ. Getting rid of the old viscous fan is amazing. I thought it would much worse given they usually pack more into every version. And the compressor in the boot will save that rubbish job when it comes time to rebuild it.

The main problem i have is that nothing seems to work the way it should - paddles don't shift but now i've read it may be a setting. Stop/start hasn't worked yet, nor has it run in only electric mode but seems to be showing power drain and regen...i'm hoping in most cases it's more about the fact that i don't know how to use the car than a real problem. Strange that it's only 3 yrs newer than my MY13 L320 but they are chalk and cheese the way they drive - even with 700N.m on tap it feels way more sluggish than the L320.

Right, off to read the service manual from Naks to see if there's anything about how to change the cam belt on it...will keep you posted.

Good luck with it - brave indeed but assuming it all works as it should, an interesting choice.
The engine as I understand it is the standard V6 diesel so should be no nasty surprises there. I assume your 320 was the V8 then? - otherwise it should be pretty much the same drivetrain with the added electrical magic.
Lack of stop-start and no 'electric only' would concern me as both point to low power issues. You're clearly braver than me as I don't think I'd have bought it until I'd seen both working. That said, if the starter is 12v, it could be a weak 12v battery rather than anything to do with the HV side. I'd still expect it to creep forward in traffic in electric mode though.
It'll be interesting to hear about this rare beastie! 2021 L494 D300MHEV Autobiography
2019 Discovery Sport D180 HSE

That's a brave move, hopefully it ill work out for you!!

The Column UJ gaitor can be replaced easily enough without the £200 expense of a complete new assembly. I used this one: -

https://www.ebay.co.uk/itm/276395818357?

It's a bit pricey, but good quality, I'd go as far as to say better than oem.

The Cambelt and rear belt change is the identical procedure as the normal 306DT, the accessory drive belt does not drive the ac pump on the Hybrid model, nor is there an alternator.

Found a bit of blurb about selecting the EV only mode as below: -

The EV mode switch controls the selection of the EV hybrid driving mode. The switch is a non-latching switch installed in the Terrain Response® switchpack, in the floor console. Pressing and releasing the switch produces a high speed CAN message from the Terrain Response® switchpack to the ECM via the gateway module. With the first press and release of the switch, the ECM adopts the EV driving mode. When the switch is pressed and released again, the ECM returns to the standard hybrid driving mode. When EV mode is selected on, a LED (light emitting diode) in the switch is illuminated.

To guard against incorrect operation or a broken switch, if the switch is pressed for more than 10 seconds no change of state occurs. If the input from the EV mode switch is held high for more than one minute, a DTC (diagnostic trouble code) is stored in the Terrain Response® switchpack.

Electric Vehicle Mode Warning Indicator
An EV mode warning indicator is located in the instrument cluster. The warning indicator is illuminated when the EV mode is selected on. When the motor generator is running without the engine, the warning indicator illuminates green; when the engine is running the warning indicator illuminates gray. Operation of the warning indicator is controlled by a high speed CAN bus message from the ECM.

EV Blurb - General operation.

The TDV6 3.0L diesel engine management system is controlled by the ECM and is able to monitor, adapt and precisely control the fuel injection and electric throttle. The ECM uses multiple sensor inputs and precision control of actuators to achieve optimum performance during all driving conditions.

The ECM controls fuel delivery to all six cylinders via a common rail injection system. The common rail system uses a fuel rail to accumulate highly pressurized fuel and feed the six, electronically controlled injectors. The fuel rail is located in close proximity to the injectors, which assists in maintaining full system pressure at each injector at all times.

The ECM constantly monitors the inputs from the APP sensor and the control modules of other systems to determine the overall torque output required from the engine and motor generator. The ECM also monitors the state of charge of the HEV battery. Torque arbitration by the ECM software determines the torque required from each power source to produce the overall torque output. The ECM then operates the fuel injectors and electric throttle to produce the torque required from the engine, and/or transmits the torque required from the motor generator to the EPICM on the high speed CAN HEV systems.

NOTE: If the engine temperature is too high, the HEV battery state of charge gauge is replaced by the ECT gauge.

The ECM automatically stops and starts the engine as required for the different HEV driving modes. Illumination of the warning indicators normally associated with an engine shut down, for example the ignition and low oil pressure warning indicators, is suppressed when the engine stops in HEV operation.
In the following circumstances the ECM always runs the engine and only uses the motor generator for boosting, if required:

If the transfer case is in low range.
If a Terrain Response® special program is active.
If the suspension is selected to off-road height.
If the HEV battery has a low state of charge.
The ECM adopts different HEV driving modes in order to optimize fuel economy throughout the drive cycle.

The driving modes are:
Hybrid drive.
Boosting.
Regenerative braking.
Coasting.
EV (electric vehicle).
EV inhibit/sport.

HYBRID DRIVE MODE
In hybrid drive, while the torque demand from the driver is low, the ECM uses the motor generator to provide the drive into the transmission. When the torque demand exceeds a pre-determined level, the ECM starts the engine and uses it to provide the drive into the transmission instead of the motor generator.

BOOSTING MODE
At high torque demands the ECM supplements the drive from the engine with torque from the motor generator to boost the total torque output.

REGENERATIVE BRAKING MODE
During braking, the ECM signals the EPICM on the high speed CAN HEV systems to operate the motor generator in the generator mode. The road wheels then drive the motor generator, and the braking effect this produces is incorporated into the braking torque applied by the brake system.

COASTING MODE
If the throttle pedal is released, but the brake pedal is not applied, the vehicle enters an over-run condition. and the ECM operates the motor generator in generator mode. At higher vehicle speeds, to avoid slowing the vehicle too much, the ECM sets a low generator output. The low generator output is used to charge the 12 volt battery system and provide power for the electric A/C compressor (if required). At lower speeds the ECM sets a higher generator output, which is used to charge the HEV battery.

ELECTRIC VEHICLE MODE
In EV mode the ECM maximizes use of the motor generator to drive the vehicle. For EV mode to activate, the following conditions are required:

Ignition in power mode 7.
No HEV system fault logged that requires the engine to keep running.
Accelerator pedal demand does not exceed the capability of motor generator.
The HEV battery state of charge is equal to or greater than the calibrated EV entry minimum.
HEV battery discharge power capability is equal to or greater than the calibrated threshold.
The ECT is 50ºC (122ºF) or more.
The transfer case is not in low range.
The wade sensing system is inactive.
The suspension is not in off-road height.
The transmission does not require the engine to keep running (as it does when changing gear, for example).
There is no active Terrain Response® special program.
When the EV mode switch is pressed the TRS (Terrain Response® switchpack) transmits the switch selection on the high speed CAN chassis systems to the gateway module. The gateway module transfers the message to the high speed CAN powertrain system. On receipt of the message:
The instrument cluster illuminates the EV mode warning indicator and the engine start marker.

The TCM adopts a different shift strategy to make best use of the torque available from the motor generator.

The ECM:
- Sends a signal to the TRS to illuminate the indicator LED in the EV mode switch.
- Reduces the value of available HEV battery power transmitted to the ATCM, which reduces the speed of
the electric A/C compressor to conserve power.
- Stops the engine, if running.

In EV mode, using only torque from the motor generator, the vehicle has a range of approximately 1.6 km (1 mile). If torque demand is kept below the engine start marker, the ECM uses only the motor generator to drive the vehicle until the HEV battery state of charge decreases to a point where it can no longer provide sufficient power. The ECM then starts the engine again to drive the vehicle and signals the EPICM to switch the motor generator to the generator mode and recharge the HEV battery. When the engine starts the EV mode warning indicator and the engine start marker in the instrument cluster change color to gray until the HEV battery state of charge has recovered sufficient to drive the motor
generator again.

ELECTRIC VEHICLE INHIBIT/COMMANDSHIFT MODE
The EV mode is inhibited when the auto stop/start system is selected off or the transmission is in CommandShift mode.
The engine runs continuously and the motor generator provides boosting assistance when required for maximum performance. The ECM disables driving with solely electric power when in this mode.
When the transmission is in CommandShift mode the power gauge in the instrument cluster is replaced with a standard tachometer.

Management of HEV System Faults
The ECM is in constant communication with the components of the HEV system. If a fault is reported by any of the components the ECM sends a command to the instrument cluster to display the relevant warning indicator and text message.

The stand out statement for me is "In EV mode, using only torque from the motor generator, the vehicle has a range of approximately 1.6 km (1 mile)" - Wow all that for just 1 mile!!

Good luck with the purchase, I'm sure we'll all be interested to hear how it performs.

ShouldHaveStuckWithAudi wrote:

paddles don't shift but now i've read it may be a setting.