Land Rover Strategy - Fault Code

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Land Rover Strategy - Fault Code

Postby STC » Wed Feb 22, 2017 9:59 pm

P115B.JPG


This came to me with the symptoms
1. Restricted Power
2. Engine cuts out
3. Fuel Gauge stuck Reading Zero, with Full tank of fuel.

Standard easy Diagnosis, one of the 2 Level sensors in the tank open circuit. Replaced the Sensor and carried out TSB wiring modification to in tank wiring connectors. Solved and gone.


The fault code description for P115B made me stand back and look again - "Low Fuel Level - Forced Engine Shutdown"

The subject of this car arose whilst talking to Steve Smith & Alan and they were equally astonished at that ECU strategy, just as I was.

Above is a screen shot of the Description for P115B from Jaguar Land Rover Topix.


Better to stop it whilst before the Pump & Injectors are run dry of lubricant and save the hassle of bleeding it etc. I'm guessing ??

A bit naughty when there are 2 tank level sensors, one of which was correctly showing there was fuel in the tank ???
Last edited by STC on Fri Feb 24, 2017 9:56 am, edited 1 time in total.
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Re: Land Rover Strategy - Fault Code

Postby KimAndersen » Thu Feb 23, 2017 1:00 am

Hi STC

You are absolutely right regarding the strategy of trouble code P1115B.

There is a excellent description of this code in the Denso service manual over Common Rail System (SRC) where the ECU strategy is called " Run Dry Prevention (RDP) Control"

Run Dry Prevention (RDP) Control.jpg
Run Dry Prevention (RDP) Control


Regards
Kim
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Re: Land Rover Strategy - Fault Code

Postby Dcunning35 » Thu Feb 23, 2017 2:30 pm

Its the same strategy on all the euro 5 and 6 diesel fords now ! The other good one is egt over temp we only need to see 1 egt out of range to cut an engine!!! Rather a frighening expierience in the fast lane of a motorway.
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Re: Land Rover Strategy - Fault Code

Postby volrem » Thu Feb 23, 2017 4:00 pm

Does these cars with that strategy have piezo injectors?
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Re: Land Rover Strategy - Fault Code

Postby Dcunning35 » Thu Feb 23, 2017 9:24 pm

The fords do yes, either continental or delphi piezo units
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Re: Land Rover Strategy - Fault Code

Postby STC » Fri Feb 24, 2017 9:37 am

Volrem

Does these cars with that strategy have piezo injectors?


Cannot be 100% certain, however if Ford are using them then I presume that Land Rover will be too. Cannot see them sharing an Engine and fitting different Injectors - Of course, anything is possible!

Why do you ask ?
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Re: Land Rover Strategy - Fault Code

Postby volrem » Fri Feb 24, 2017 9:32 pm

STC wrote:Volrem

Does these cars with that strategy have piezo injectors?


Cannot be 100% certain, however if Ford are using them then I presume that Land Rover will be too. Cannot see them sharing an Engine and fitting different Injectors - Of course, anything is possible!

Why do you ask ?


I can undestad that strategy on piezo injectors because these are very sensitive. Run dry and it's toasted. Injector repairer can fill that element again but when you run out of fuel and fill up then possibly you won't be able to start engine. There is rail pressure sensor that should avoid that but ...

Know several cases when injector is removed and after installing doesn't work again correctly. Because piezo element has drained (injectors need to be hold vertically and horisontally. Also when there is no backpressure in return line they behave bady and have great chance to be damaged.

Siemens injectors for example Volvo 2,0D has dry piezo so these don't suffer this but injectors with wet piezo do.

So if you have low fuel then there is great possibility that some amount of air enters injector and damages it. No problem with solenoid injector.

I may be totally off with that but just my humble idea.
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Re: Land Rover Strategy - Fault Code

Postby volrem » Fri Feb 24, 2017 9:39 pm

My last post is totally off. Did some google and found it from Denso manual:

http://www.service-engine.com.ua/webroo ... Engine.pdf


7.5 Run Dry Prevention (RDP) Control
Outline
When the diesel fuel is completely expended, engine restartability may worsen. To prevent the
aforementioned situation, a pseudo-gas shortage condition is created, alerting the driver that fuel is in short
supply. The driver is thus prompted to refuel the vehicle, therefore avoiding an actual empty fuel tank.
Operation
The engine is operated according to processes 1 through 5 in the figure below.
‡ 1: A fuel gauge "E" level signal is inputted to the engine ECU via CAN communication.
‡ 2: The engine ECU command injection quantity begins to be summed.
‡ 3: When the summed value for the engine ECU internal command injection quantity is greater than "A",
the injection quantity guard is set to value "a", and output control is initiated. DTC: P115A is detected.
‡ 4: When the summed value for the engine ECU internal command injection quantity is greater than "B",
the injection quantity guard is set to value "b", and hesitation operation is initiated. For details on injection
quantity control during hesitation, refer to the figure below. DTC: P0313 is detected.
‡ 5: When the summed value for the engine ECU internal command injection quantity is greater than "C",
the engine is stopped. In addition, the injection quantity guard is set to value "c", enabling restart and lowspeed
driving. DTC: P115B is detected.
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Re: Land Rover Strategy - Fault Code

Postby STC » Sat Feb 25, 2017 4:34 pm

Thanks Volrem

Useful document & thoughts.
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Re: Land Rover Strategy - Fault Code

Postby STC » Sun Feb 26, 2017 11:00 pm

Danny
Rather a frighening expierience in the fast lane of a motorway.


Clearly you do not live in the vicinity, or a frequent user of the M25 ? :D :D :D


On a serious note - that is a worrying thought !!!
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