AC not commanded turbotweak adjustments

[Momar]

I was going to mess around a little with the in chip tuning on my tt chip. Well, In order to get the values to cycle, it has to see u turn on the ac. I tried this, and no values changed. I tried jumping the ac pressure switch with no success either. What exactly does the computer see happen that it knows that you have commanded the ac on.

Also, I am using Winaldl for now. It shows a flag for no ac commanded, and that doesnt change even when I try to turn it on. I dont know if that flag is should change w/ our cars, but thought I would mention it.

Another thing, is that I think I recall reading something about the 02's being off on these cars. I am showing about .930-.950 under wot. I would assume that that is a bit on the high side, but dont know how far off winaldl is???

Thanks

Ben

 

[Momar]

ttt

 

[onefastcar]

go to gnttype.org and read up on these cars they have tons of info for you to get to know these cars and thier intricacies, about the chip ign. on ac on and adjust by fan do you have a scanmaster i presume yes no problem adjusting mine if you have problems contact eric i'm sure he would help, also if you don't have an adjustable fuel pressure regulator ya need to get one but i am assuming yes with your mods.

 

[Danster]

Do you have the digital AC unit? If so, I think you need to ground a wire in the ECM? Do a search and you'll find the answer.

Dannyo

 

[Momar]

I have the manual ac. It not a problem w/ the chip. My ecm is not seeing the ac being commanded on. I looked at the wiring diagrams in alldata, and it looks like both the coolant fan and the ecm part run through the pressure switch on the accumulator. I tried jumping it last night to no avail. I am going to check for voltage at the light green wire(power side) on the switch w/ ac turned on. I the blower motor is kicking on so the head unit is working, but it runs a different wire path that bypasses the pressure switch.

Ben

 

[pacecarta]

at the ecm lt blue wire at B8, you need to see 12v with a/c switch on

if not just supply 12v to it through a switch , i have it like that in my 86 which has no A/C , I also ran a switch for the air sensor off the ecm and have both in the console ashtray , much easier to program that way

btw, erics has new stuff doesnt use the a/c or air temp sensor but i like the switches better

 

[turbobose13]

Did you disconnected the air sensor at the air filter.

 

[Momar]

Did you disconnected the air sensor at the air filter.

yes

 

[Momar]

yes

Well, I did a little testing, and I have power clear through the pressure cycling switch and to the relay, but power doesnt make it to the compressor clutch. I am not sure if it is a bad relay or wiring, or even if that would make a difference in the ecm seeing the ac commanded on since it appears to branch off before the relay in the diagram.

Ben

 

[salvageV6]

Pacecarta is correct, you need to see +12 on the light blue ECM wire pin B8.

When the A/C switch is "ON".

Or via an external temporary programming connection.

 

[Momar]

Pacecarta is correct, you need to see +12 on the light blue ECM wire pin B8.

When the A/C switch is "ON".

Or via an external temporary programming connection.

Is there a way to test that without damaging the ecm?

 

[salvageV6]

A simple voltmeter can see if you have voltage there with the Key 'ON' and A/C head set to A/C MAX, by pass the low side pressure switch with a jumper wire, if you don't read +12 on that wire at the ECM with the meter.

The ECM uses a pullup resistor to ground there so it expects the +12 signal hence the reason you can add a switched +12 wire right to that blue wire.

When I program my translator system which has an ECM connection as well I just run a long wire with a clip lead to the battery, I finally made a jumper switch just this week that is plug and play at the ECM when I need to program, looks neater than a 8 foot long wire coiled up there.