I've got a 2016 L405 with the 3.0 TD6 engine. I know this is the D5 thread but am having limited responses in the L405 thread so figured I'd check here since the powertrain is the same between the two.

It currently has a difficult time starting (Cranks maybe 3-5 seconds before firing up) and once started it will idle for a few seconds then stall. When the engine is cold it may only stall once, but when the engine is warm it may repeat this 5-6 times before it stops stalling. Once running it idles and revs smoothly with only occasional hiccups. Following this it will typically run fine but when driving and coming to a stop once the engine reaches idle it may stall again. It has also gone into restricted performance once or twice. I cleared the engine codes then drove the vehicle on a short drive around the neighborhood and the following codes for the fuel system returned:

P00C6 - fuel rail pressure too low - engine cranking
P0087 - Fuel rail/system pressure - too low
P0088 - Fuel rail/system pressure - too high
P228F - Fuel Pressure regulator 1 - Exceeded learning limits - too high

Any ideas where to start?

When monitoring actual fuel pressure vs desired, I'm seeing a lot of variation on bank A along with the sensor reading fluctuating between 220 and 660 kpa with the engine completely off. It also looks like the fuel pressure never quite reaches the desired pressure.

I know there was a TSB for the 4.4 TDV8 where I believe the rail pressure sensor wiring ground was faulty? Could that also apply to the 3.0?

I've seen crank position sensors that act up cause similar symptoms but without the accompanying low and high fuel pressure codes.

Any suggestions are appreciated.

 

Are you able to verify the fuel pressure prior to the high pressure pump? I wonder if the lift pump in the tank isn't providing enough fuel to the HP pump. How long since the fuel filter has been replaced?

Also... most of those codes have a JLR two digit sub-code that gives more detail. Any chance you have a scan tool that can read those?

 

Yeah here’s the full codes:

• P00C6:00
• P0087:21
• P0087:84
• P0088:22
• P228F:22

I am planning on replacing the fuel filter this weekend. I will have to see if there’s a sensor for the low pressure pump to verify if it’s producing enough pressure.