Thread: Change ECU from D2 to D2a - ? 3- 4 wire?

What parts are required when changing over from D2 to D2a ecu (have a faultmante MSV now) to give the later specifications and mapping. Have looked in the LandROver manuals which i purchased a month ago and it doesn't seem to differentiate between the two set ups.

Thanks

Arty

I am under the impression that a remap / upgrade may have already been done oj this NNN but reverts to lesser tune for the 10P due to lack of inputs (?), sort of hoping for a cheaper remap really and had read somewhere re a changeover of parts -3 to 4 wire reference and or different injectors- to allow the higher tune to work

Ahhhh reading the given thread,thanks Chook, I think must have read this at some time as within is this information on just page 2

The poster had finally fixed the faults by replacing the existing AAP sensor in the air box with a 4 wire version from the EU3 motor. The EU3 AAP contains an additional temperature sensor attached to C0158-30 which is shown in the RAVE pinout table as "Not Connected". HOWEVER in the text description for the AAP mentions that the temp sensor is in fact connected to pin 30.

I had been wondering about what effect the missing temp sender would have, and then it dawned on me that the density of a gas is related to temperature and pressure. The IAT/MAP sensor on the intake manifold contains both pressure and temp sensors, so fuelling strategy must already be partially based on intake charge density. So I have to assume that the EU3 motors are using the difference in density between air box and intake manifold rather than pressure differential.

What this means for the EU2 motor running a EU3 map I'm not sure, but I think we can assume that a default value is being substituted for air box temperature, which will potentially result in less than optimal fuelling at ambient temperatures above or below the default. The forum post mentioned above indicates this could have a significant effect on fuel consumption.

Why the lack of temp sensor results in a Coolant Temp fault is a bit curious - it may be that the fault codes are lumped together and possibly a testbook system can differentiate based on additional information.

So what is the fix? We have two obvious options, first is to use an EU2 base map and avoid the issue in the first place, and second is to retro fit the later 4 wire AAP and give the ECU the missing information.

Retrofitting the 4 wire sensor is definitely doable. It does also require replacing the plug at the air box and running an additional wire back to the ECU. The pin at the ECU is unused on the EU2 motors so it is a simple matter of crimping on the correct type of pin. It was mentioned that the later AAP sensor also requires a different lid on the airbox and Microcat does list a different part numbers for EU3 lid. The post reported a substantial improvement (~4mpg) in fuel economy after this change was made.

and researching further - AAP/AAT sensor swapping | DiscoTD5.com

All this said, this is to be daily driver (very little really approx 100K's pw) and the back up 4WD more for personnel and the 300TDi the carrier with the fridge!

Thanks for the guidance, as it appears a relatively easy upgrade I am
now arranging to get these parts as well as the upgraded inter-cooler

Regards

Arty