A/C Problem

[ians13]

Well I fixed my A/C a short time ago, now when ever i turn it on my idle drops from 700rpm to 500rpm i know that the idle should go up or atlest hold the same idle that should be controled by a load switch some were, i just wanted to know if any one has this problem. and were can i find the ac load switch or what ever controls the ac load idle.

 

[Nick M]

Pull your DTC's. Push in the A/C button when you do it. You are looking for code 51.

 

[ians13]

Pull your DTC's. Push in the A/C button when you do it. You are looking for code 51.

am sory what is a DTC's troble codes?

what is 51

 

[mrnickleye]

The computer codes. Check the TSRM on how to get them.

http://groundsky.co.nz/techinfo/TSRM/

The computer senses a load, and raises the idle thru the ISC.

 

[Nick M]

51 comes up if the A/C switch is on. If you push the button, and don't get 51, then you know why you have the low idle. The A/C signal is not reaching the ECU, which is why you do not have the command.

But you need to see if you have 51 with the A/C button pushed in.

 

[jdub]

51 comes up if the A/C switch is on. If you push the button, and don't get 51, then you know why you have the low idle. The A/C signal is not reaching the ECU, which is why you do not have the command.

But you need to see if you have 51 with the A/C button pushed in.

I knew this was where you were going...very nice Nick :bigthumb:

 

[ians13]

ok i'll try this and see what i get, lets assume that the signal is not getting to the ecu, it would have to be getting a signal from one of the sensors in the high pressure line. am going to have to investigate this.

 

[mrnickleye]

Turbo......PG 4 in the AC section of TSRM shows a wire from the AC amplifier going to the EFI?
http://groundsky.co.nz/techinfo/TSRM/24_AC.pdf

PG 6 also. "to EFI"

http://groundsky.co.nz/techinfo/TSRM/24_AC.pdf

This would be the signal that tells the ECU to up the idle.

Last month we had a truck with a burnt amplifier. The ac would not work. After installing a new amplifier, all was fine, including the idle up.

Inside that one was a small relay that finally cooked.

Our cars are a bit different, but this info may help you.

 

[ians13]

could this also explain why my ac does not work on low speed.
i'll check this out this week end.

 

[Nick M]

could this also explain why my ac does not work on low speed.
i'll check this out this week end.

Elaborate on that a little more please. The fan is the issue, or the air is not cold on low speed?

 

[johnathan1]

The idle problem is either the A/C amplifier (or wiring to it) or the ISC. Check by pulling codes with the A/C button pushed in like Nick said.

The fan speed problem is likely the resistor pack in the passenger footwell.