e36 PnP Wiring Feedback

[My5t3ryM4nN]

Hi All,

I've attached a picture and PDF for my current wiring thought process for my e36 project and wanted to get some final feedback for my game plan. 

I'm using the following items for the build:

• Link PnP G4X
• Link MXS Dash
• XS Expansion Loom 
• Boost Solenoid 
• Ethanol Sensor
• Pressure Sensor for Fuel
• Pressure/Temp Combo Sensor For Oil
• Boost Level Switch (On/Off)

A couple questions I had:

1. On the XS expansion loop I'll be running 20 AWG for everything which seems fine since they're all sensors/switches. I just don't know what to do for wiring in the boost level switch. I've read I can use a ground rather than a 12v source. Would I be using a chassis ground or the sensor ground from the expansion harness? 
2. For the Ethanol sensor, boost solenoid, and Link MXS I planned on wiring everything with 20 AWG as well, my only concern was the CAN Lambda, is that fine with 20 AWG as well? I've seen several threads and documents all with varying information.
3. Would it be beneficial to have the CAN Lambda on it's own relay separate from the Ethanol sensor, boost solenoid, and Link MXS?
4. On the Ethanol and Boost solenoid are the two pins that are listed a good option for those items? 
5. Final question, does the Can Hi/Lo need to use a specialty twisted cable or shielded or etc? Or can I just use typical 20 AWG Tefzel wire?

Thanks for the help!

E36 Wiring Pt2.pdf

[Adamw]

 

1. The switch can go to 5V, 12V or Gnd.  Any ground is ok.  All it needs to do is rise above 2.0V or fall below 1.5V. 
2. 20AWG would be fine for all of those.
3. The lambda would ideally be on its own relay since the mac valve will be generating quite large voltage spikes, this can upset some of the error tests that the lambda controller does.     If you add the capacitor as shown in the alternative diagram in the quick start guide it would likely be ok.
4. You have the ethanol sensor and mac valve pins swapped.  Eth goes to a DI and Mac goes to an Aux.  The proposed pins would be fine.
5. Just standard wire hand twisted is all you need.

[My5t3ryM4nN]

On 12/21/2022 at 7:49 PM, Adamw said:

 

1. The switch can go to 5V, 12V or Gnd.  Any ground is ok.  All it needs to do is rise above 2.0V or fall below 1.5V. 
2. 20AWG would be fine for all of those.
3. The lambda would ideally be on its own relay since the mac valve will be generating quite large voltage spikes, this can upset some of the error tests that the lambda controller does.     If you add the capacitor as shown in the alternative diagram in the quick start guide it would likely be ok.
4. You have the ethanol sensor and mac valve pins swapped.  Eth goes to a DI and Mac goes to an Aux.  The proposed pins would be fine.
5. Just standard wire hand twisted is all you need.

Awesome thank you for the feedback! 

Sadly after checking I don't have Pin 11 or 57 on my harness, would there be any issue with using the factory O2 or MAF sensor pins for the Boost solenoid and ethanol sensor?

I do believe I also have the purge valve available from the evaporator (Ign 8, Pin 36)

[Admiral Akhtar]

14 hours ago, My5t3ryM4nN said:

Awesome thank you for the feedback! 

Sadly after checking I don't have Pin 11 or 57 on my harness, would there be any issue with using the factory O2 or MAF sensor pins for the Boost solenoid and ethanol sensor?

I do believe I also have the purge valve available from the evaporator (Ign 8, Pin 36)

I don't believe the O2 or MAF circuits have a DI input which you will require for the Ethanol sensor 
The Purge valve pin should be fine for the MAC valve, as being on a spare IGN channel, it will work fine for PWM.

You can use the DI on the expansion loom that you currently have set for the MAP switch for the Ethanol instead, and then if you use a spare Aux/AN volt channel like the MAF AN volt 6 you previously mentioned as a GP Input under digital inputs, that can function as your MAP switch.
Alternatively, you should also have spare DI channels under Pin 64 Blower Idle Up, Pin 65 A/C Request, or Pin 81 Auto Trans Range switch

[Adamw]

On 12/26/2022 at 9:33 PM, My5t3ryM4nN said:

I do believe I also have the purge valve available from the evaporator (Ign 8, Pin 36)

I would not use an ignition drive for the boost valve, the ign drives dont have flywheel diodes so you will get slower response than a proper aux since the magnetic field will be slower to collapse and the high flyback voltage possibly wont do the driver much good in the long term.  

How about aux 4/pin46?

[curly]

Wiring aside, I'd like to ask the question, why are you using the MAP switch? I'm racking my brain trying to figure out the scenario that needs a MAP switch that could tell the ECU anything the internal logic off the MAP sensor couldn't. Unless you're doing all of this through a MAF?

[Adamw]

7 hours ago, curly said:

why are you using the MAP switch

Map, not MAP.  "Map Switch" is a term I mostly hear from English/UK users - it refers to a switch which changes the tune/tables/config/map or whatever the ecu can do, that may be high octane/low octane, high boost/low boost, economy/power for example.

[curly]

Ooooh I get it now. I'm used to seeing MAP switches with 335s, for fuel pumps, so that's where my mind went. Thanks for the clarification.

[My5t3ryM4nN]

On 12/27/2022 at 5:20 AM, Adamw said:

I would not use an ignition drive for the boost valve, the ign drives dont have flywheel diodes so you will get slower response than a proper aux since the magnetic field will be slower to collapse and the high flyback voltage possibly wont do the driver much good in the long term.  

How about aux 4/pin46?

Hi Adam, thanks for the support as usual

I finally had a chance to go through the pinout on the harness and color code it based on what I do/don't have. I've attached a photo below

• Green = Called out in BMWlink pinout correctly
• Yellow = Existing Pin but not called out in BMWlink pinout 
• Red = No Pin but called out in BMWlink pinout

BMWLink Pins:

• Pin 11, Aux 7, Throttle Valve Position (TCM)
• Pin 14, nc
• Pin 57, DI4, Timing Intervention Request (TCM)
• Pin 60, nc
• Pin 66, nc
• Pin 87, nc
• Pin 88, nc

E36 DME Harness Pins

• Pin 11, nc
• Pin 14, Output, Hot Wire Mass Air Meter, Hot Wire Mass Air Meter
• Pin 57, Input, Ignition Timing Intervention, Transmission Control Module (EGS)(Not sure where this wire runs into the harness yet)
• Pin 60, Input, Programming Voltage, Datalink Connector
• Pin 66, Input, Driveway protection signal (Code), Starter Interlock Module
• Pin 87,  Input, RxD, diagnosis line, Datalink Connector
• Pin 88, Input/Output, TxD diagnosis line, Datalink Connector

 

Based off of this whole exercise I'll do the following for the Ethanol/Boost/Map Switch:

• Ethanol sensor ran to Pin 64 (DI3), 65 (DI2), or 81 (DI5) on the factory harness (Which ever one is easier to get to)
• Boost Solenoid ran to Pin 46 (Aux 4) and to a chassis ground (Just need to find where Pin 46 runs into the harness)
• Map switch ran to DI7 on the XS Loop 

Let me know if I covered all my basis, Thanks again!

 

[Adamw]

3 hours ago, My5t3ryM4nN said:

Based off of this whole exercise I'll do the following for the Ethanol/Boost/Map Switch:

• Ethanol sensor ran to Pin 64 (DI3), 65 (DI2), or 81 (DI5) on the factory harness (Which ever one is easier to get to)
• Boost Solenoid ran to Pin 46 (Aux 4) and to a chassis ground (Just need to find where Pin 46 runs into the harness)
• Map switch ran to DI7 on the XS Loop 

Boost solenoid needs ignition switched +12V on one side, ECU aux on the other.