TD5 to V8, how about AirCon and ABS?

[doezel]

Hi All,

I'm in the middle of replacing the TD5 engine for a V8 with Megasquirt MS3X ECU in my 2003 110.

Now I'm removing the old wiring and ECU for the TD5 and I've noticed that some of the wires from the TD5 ECU are connected to the ABS module and are used for the Aircon.

I've identified the following: (I use the Defender MY2002 wiring diagram and the ECU pinouts from the NANOCOM site)
https://nanocom-diagnostics.com/downloads/preview/lucas-td5-diagnostic
https://www.nanocom-diagnostics.com/uploads/downloads/WABCO D TYPE (DEFENDER) ECU Guide.pdf
 

For the WABCO ABS module there are 2 wires going from the ECU to the ABS:
They are going to connector 2;
WABCO pin 10 (Throttle Position Sensor)  goes to TD5 ECU pin 32 which is marked "ABS" 
WABCO pin 11 ( First Gear) goes to TD5 ECU pin19 which is marked "TACHOMETER ENGINE SPEED" ???
Has anyone ever rerouted these signals? Any tips? If not I'll measure them on another TD5.


For The Aircon there are 4 wires connected to the ECU
B4 (Cooling fan relay) 
B9 (A/C clutch request) Coming from the "Sensor-pressure-Air Conditioning"
B23 (A/C Fan request) Coming from the "UNIT-AIR-CONDITIONING AC)"
B29 (A/C Relay)

However, on the 300TDI wiring diagram I see that these 4 wires are linked to components marked as:
SWITCH-FAN-AIR CONDITIONING (A/C) (S229)
SWITCH-CLUTCH-AIR CONDITIONING (A/C) (S207)
Can anyone tell me what these 2 components do? (I presume they switch something, but where are they located and when do they switch?)

 

Thanks for any info.

Cheers!

[elbekko]

Aircon is typically so the ECM knows an extra torque demand is coming up, and potentially can even deny it (if it's in limp mode etc). I would think you can just wire the request straight to the relay, but check out the signals properly first.

The others might be more difficult. From RAVE:

The engine speed you should be able to output from MS, I think you have plenty of spare outputs? But the PWM signal might be difficult, not even sure what all they could be saying there.

[doezel]

Thanks elbekko! 

Your Rave screenshot left me puzzled! Also the connector codes didn't match with my wiring diagram.

I found out that the part you've placed a screenshot here is from a Puma defender:
https://www.lrworkshop.com/connectors/defender-2007/C0504

The connector I have is the C0504: (pin 10 and 11)
https://www.lrworkshop.com/nl/connectors/defender-2002my/C0504

Can't find that text about a TD5 in rave though. Maybe you can find it?

Cheers

Edited November 19, 2020 by doezel

[elbekko]

My screenshot was from the 2002 Defender RAVE, Puma isn't in there. The 1999 RAVE doesn't seem to mention those wires.

Full screenshot for reference:

[doezel]

ah damn!  I'm referring both times to the C0504..... 🙂 

My bad! further investigation necessary...