VAT system

[vetteoz]

The pressure switch is not hooked up yet. So if the pump kicks back on after cranking, I can assume the ignition module in the dist is OK then? If I'm reading that correct... the ecm is seeing the ref pulse and kicking the pump on.

That would indicate ECM is seeing correct dist ref pulses and kicking in the relay

it seems as if the ALDL on the TPI should have 8 wires or maybe 5 wires.
On the schematics I see on the main harness plug 5 go to the ALDL but then when I look at the ALDL schematic it shows that there are 8 wires coming from it.
Does this sound correct?
Also if I do get the ALDL plug wired up, where do I hook the wire from the check engine light into?

All you need at present is the check engine light wiring and the diagnostic wire
( Wht /Blk off ECM A9 ) to the ALDL terminal A ( gets grounded to put ECM in diagnostic mode and flash the SES )

Other than the serial data line for datalogging (ECM A8 ) , other wires to ALDL are for other purposes and do not go back to the ECM
For checking fuel pump and TCC operation , etc

 

[corvette66]

cool, ALDL is all hooked up. All i got to do now is figure out how the Check engine light hooks into this mess. Im going to locate the wires in the dash that go to the SES and hopefully figure out what to hook them to.

chevy thunder says the under dash terminal plug (prong C) (ecm A5) this wire is the SES wire and goes to the ground side of socket. OK now im going to go rip the dash apart

 

[corvette66]

OK so I got the wire from the ECM A5 going to the ground side of the SES light and a known working bulb in the slot. I have on the ALDL plug the 2 wires needed: pin A on ALDL blk/white going to ground, wht/blk from ECM going to Pin B (according to ChevyThunder)

oz, you said that the wht/blk goes to Pin A on the ALDL, Would this be just a bypass of the Actron tool? I assume that the Actron toool just loops the wht/blk to the blk/wht (pin A & B) I have the tool so I just hooked it up according to chevy thunder.

I then pluged the tool in and I have nothing at the check engine light. the light doesnt even turn on. Now before I even got started with swaping wires on the SES, I turned the ignition on to see if the SES even worked. It did not, as the bulb was el burnto. So I used the ABS bulb in place. The cool thing I found about GM dashes doing this SES thing is the wires going into the dash are all ground wires. The positive leads of all gauges and bulbs semed to go off in a different direction to one source. So hooked the ECM wire to the "SES ground" was no problem.

does it sound like I had everything right?

 

[boomdriver]

cool, ALDL is all hooked up. All i got to do now is figure out how the Check engine light hooks into this mess. Im going to locate the wires in the dash that go to the SES and hopefully figure out what to hook them to.

chevy thunder says the under dash terminal plug (prong C) (ecm A5) this wire is the SES wire and goes to the ground side of socket. OK now im going to go rip the dash apart

heres a basic drawing of the display wiring that includes the SES...Hope this helps.

I'm trying to find a acdl drawing but I can;t find one pic of the whole thing with color/pin position...it's broken down into the various systems that it holds so its scattered over 6 pages.
If you get the SES lite wire sorted out, all you really need at that point is a bulb to blink..

Hope the attachment blows up enough to read ! if not, I'll try again with a higher resolution or file copy.