MSS54HP required for MAP?

[ATB88]

See post 12 in my old thread for detailed instructions to do the EWS-resync using Tool32: https://nam3forum.com/forums/forum/m...o-stock-wiring

[D-O]

See post 12 in my old thread for detailed instructions to do the EWS-resync using Tool32: https://nam3forum.com/forums/forum/m...o-stock-wiring

Many thanks, sir.

[DirtyS54]

Okay, so as I said it is possible, with a CSL airbox install, to route the wiring for both the IAT and the MAP sensor to go via the MAF connector. This is the approach I went with as I wanted the ability to fairly easily swap back if desired.

For reference the end result of the extension loom looks like this:




The reason this can be achieved is as follows:

The pinouts for the IAT, MAP sensor and MAF sensor are:

CSL IAT Sensor
Pin 1 (IAT signal) -> DME X60003 pin 22
Pin 2 (Ground) -> DME X60003 pin 25

CSL MAP Sensor
Pin 1 (+5V) -> DME X60003 pin 7
Pin 2 (Ground) -> DME X60003 pin 17
Pin 3 (MAP signal) -> DME X60003 pin 18

Euro M3 MAF Sensor
Pin 1 (IAT Signal) -> DME X60003 pin 22
Pin 2 (+12V) -> Fused supply X8680 pin 6
Pin 3 (Ground) -> DME X60003 pin 17
Pin 4 (+5V) -> DME X60003 pin 7
Pin 5 (MAF signal) -> DME X60003 pin 1

The wiring diagrams below confirm what I've listed above:





Looking at this we can see the following:

IAT signal uses the same pin (22) for both the Euro M3 and the CSL
IAT ground uses pin 25 on the CSL and pin 17 on the Euro M3

MAP +5V uses pin 7 same as the MAF +5v on the Euro M3
MAP ground uses pin 17 same as the MAF ground on the Euro M3
MAP signal uses pin 18, which is different to the MAF signal (pin 1) on the Euro M3


So we've got two sticking points, MAP signal and IAT ground.

IAT ground is easily solved as we can use pin 17. The Euro M3 uses shared ground for the MAF and IAT, the CSL doesn't because they're wired as separate runs from the DME, but for our purposes we can copy the Euro M3 approach and use pin 17 for both (Note this is only okay to do because we know that pin 17 is configured to be used as a ground)

MAP signal can be solved by simply re-pinning pin 1 in the X60003 connector to pin 18, this is the only "change" that needs to be made to the stock wiring.

So what does our extension harness look like?

CSL IAT Sensor
Pin 1 (IAT signal) -> MAF connector pin 1
Pin 2 (Ground) -> MAF connector pin 3

CSL MAP Sensor
Pin 1 (+5V) -> MAF connector pin 4
Pin 2 (Ground) -> MAF connector pin 3
Pin 3 (MAP signal) -> MAF Connector pin 5

IMPORTANT! Remember that when you do the install you also need to re-pin X60003 pint 1 to pin 18. I recommend putting a label in the ECU box as a reminder as to what you have done so that it can be reverted in the future.


In terms of the construction of the extension loom you need the following parts:

1x Bosch 3 pin connector (1928403966) - I recommend buying genuine Bosch. Also make sure that you buy a kit that comes with the pins and seal plugs.
1x boot for Bosch 3 pin connector (1928300527) -
1x IAT connector (12521427615) - Make sure that you purchase a kit that comes with the pins and seal plugs.
1x boot for IAT connector (12521732635)
4x 3m of 0.5mm2 insulated wire - I recommend different colours for each pin as you need to know which is which after passing it through the corrugated tube. If you want to go super fancy you can purchase in the original wiring colors for each pin.
3m of 4.5mm corrugated tube. Genuine stuff is order-able in 1m lengths as (12517508831). I wanted longer length so bought some knock off from AliExpress which, except for the lack of writing on the outside, is exactly the same.
1x male MAF connector kit (see here for how to purchase)
Braided heat-shrink tubing for the MAF connector to 2x corrugated tubing

Tools required
- soldering iron
- solder
- side cutters
- tape (to aid in pulling wires through corrugated tubing)
- crimp tool for terminals (or do what I do and tack with a small amount of solder and use needle nose pliers to crimp the terminal
- exacto knife (for cutting corrugated tubing)

General approach
The general approach I followed was to:

1: use scrap wire to lay out my desired routing of the extension harness in the engine bay (to work out lengths)
2: cut wires and tubing longer than you've measured so you have spare room to work
3: make up the MAF connector end first (don't forget the waterproofing plugs!)
4: thread the wiring through the 2x corrugated tubings (making sure you get the right wires in the right tubes)
put it back in the engine bay and route it, temporarily fixing in place to get the exact lengths you need for the corrugated tubing
5: cut the corrugated tubing to length (don't cut the wires)
6: work out exactly how much length of wire you need to account for the terminals, position and orientation of the connectors, etc. and cut wires to length
7: Don't forget to thread on the waterproofing plugs and your connector boots
8: assemble the connectors making sure the end result for both is at the correct orientation
9: heat shrink the MAF connector end where the two corrugated tubes meet it
10: enjoy your handiwork!

Thanks for this!!

Can you confirm that this is identical for the Z3M engine harness?

thank you,