Was looking over the diode mod. Very good stuff. Was about to run to the local speed shop for MBC/DV, and radio shack for a diode. But then I realized you have to jump the MAP sensor. The sensor that I dont have...[sm=boohoo.gif] I have a 98 A4 1.8t quattro 5spd. SO what sensor reads boost on pre 00 1.8T's? Im willing to be ginny pig on this one. Need more Boost NOW!

 

i cant really help you out with your question...but i just ordered 10 diodes online that i should be getting in the next day, if you want me to send you one for like a buck....lemme know im pretty pumped about this thing too

--E

 

I don't think you can do the diode mod on pre-2000 1.8T's. good question though, I don't know what reads boost on the non-map cars. I don't know if anything does, it might just use the information it gets from the MAF.

 

cincyTT would be the one to ask about that.

 

Yea I PMed cincytt. He dosent know. I might try a friends MBC an see if that works. But prob wont cause boost is controlled by ECU. (Some how).

 

information is given via the N75 valve

 

Testing boost pressure control (engine code AEB only)[/align]Checking solenoid valve for boost pressure control -N75[/align]
Testing for leaks

â—�When there is no electrical signal, the long connection is closed.
â—�The two short connections are connected to each other.
â—�When actuated, the link between the long connection and the two short connections is opened. [/ul]

‒Removing boost pressure control solenoid valve (fitting location = - Item 8)
‒Connect the removed valve to the wiring harness.
‒Start final control diagnosis and actuate boost pressure control solenoid valve -N75
‒Blow into the long connection during the final control diagnosis to check whether the valve opens and closes properly, if necessary replace the solenoid valve. [/ul]









Electrical test of -N75

‒Disconnect the plug from boost pressure control solenoid valve-N75.
‒→ Measure resistance between the valve contacts using hand-held multimeter V.A.G 1526.
Specified value: 25...35 ω.
‒If the specified value is not obtained, renew valve -N75. [/ul]
Testing power supply of -N75
Note:
The boost pressure control solenoid valve receives its power supply via the fuel pump relay.









Test requirements:
Fuse -S29 OK

‒Disconnect the plug from boost pressure control solenoid valve -N75.
‒→ Connect diode test lamp V.A.G 1527 between engine ground and contact 1 on the connector. [/ul]

‒Operate starter. [/ul]
Specified value: The diode test lamp should light up.

‒If the diode test lamp does not light up, test for continuity in the wiring between contact 1 and fuse -S29 according to the current flow diagram - if necessary repair open circuit.
‒If wiring is OK, test fuel pump relay =. [/ul]
Testing actuation of boost pressure control solenoid valve -N75










‒→ Connect diode test lamp V.A.G 1527 between contacts 1 (positive) and 2 on the connector.
‒Start final control diagnosis and actuate boost pressure control solenoid valve -N75 = [/ul]

Specified value: Diode test lamp should flash. [/ul]

‒If the diode test lamp does not flash or it lights up permanently, connect test box V.A.G 1598/19 to wiring harness for Motronic control unit. [/ul]










‒→ Check wiring between contact 2 of the connector ... [/ul]













‒→ ... and contact D3 on the Motronic control unit for continuity or short to positive and repair as necessary.
‒If no wiring fault is present, replace the Motronic control unit -J220. [/ul]

 

opps missed pictures

[IMG]local://upfiles/12092/E0280A7FAAD94D4697B1C771201D949E.jpg[/IMG]

[IMG]local://upfiles/12092/BD912902049940E5A922912DA7EF9D8B.jpg[/IMG]

[IMG]local://upfiles/12092/60C03D4B5B7E4C73917D936A7FAD1517.jpg[/IMG]

 

Sweeeters!!! SO! by adding resistance to the n75 posably showing a faulty read. (Less boost) Giving it more?

 

Isn't the whole point of the diode just to trick the ecu so it doesn't put you into limp mode? If so, you wouldn't need the diode because AEB engines (nDBW) don't have limp mode.