Add IAB To P28

Author: Deluded Date: 07-24-03 23:44

READ CAREFULLY: The procedure to add IABs is different depending on how they are wired. One IAB wire will always run to the ECU, the other will run to either +12v or gnd. Choose the procedure to match how your car is wired! This is very important!

USDM ODB1 B18C: ( ECU sends ground, IAB wired to +12v )

IAB conversion... (this is for Manual cars only, but an AUTO USDM ECU converted to manual will have all the parts you need present)

Remove: R135...11F0/1720 autos only R150...1980/LS only

Add:

• Q17(A143)...already present on USDM auto 11F0/1720 (A5x, L5x, etc). Not present on EDM auto 11F0/1720 (G5x, etc).
• Q34(D1780 or C3225)... already present on USDM auto 11F0/1720 (A5x, L5x, etc). Not present on EDM auto 11F0/1720 (G5x, etc). may use PCS trans: Q31(D1780)
• jumper from right hole of R135(trans side) to D13(arrow side)

• Jumper wire for OBD1 IAB control:
  

ODB2 & JDM B18C conversions: ( ECU sends +12v, IAB wired to GND )

• above procedure not needed...

Remove: Q34

• cut control leg of IC15 short and solder signal carrying wire to it (thread wire through hole)and solder other 515 X High Side Switch pins in place
• solder other end of wire to control hole of q34.
• add C61 (1uF 35V tantalum cap) for 515 X High Side Switch.
• add Q17(A143)...already present on USDM auto 11F0/1720 (A5x, L5x, etc). Not present on EDM auto 11F0/1720 (G5x, etc).

Use P72 code with knock disabled . Similar install on LS ecus.

Pin A19 will be your IAB output on the OBD1 harness.

• High side switch for OBD2 IAB control:
  

• High side switch for OBD2 IAB control:
  

Attachment:	Modify:	Size:	Date:	Who:	Comment:
P28_IAB_1.jpg	mod	364224	12 Jul 2005 - 13:58	m2prelude	High side switch for OBD2 IAB control
P28_IAB_2.jpg	mod	212634	12 Jul 2005 - 14:00	m2prelude	High side switch for OBD2 IAB control
P28_IAB_OBD1.jpg	mod	266030	12 Jul 2005 - 17:41	m2prelude	Jumper wire for OBD1 IAB control