help...RPM DOES NOT INCREASE WHEN TURNING ON AC IN MY NISSAN B13 WITH GA15 EFI ENGINE

[saaqie786]

i have nissan b13 with ga15 efi engine, installed with sanden 508 compressor and complete ac system. The problem is that when i switch on the AC in idle position, engine switches off. the reason being, RPM not increase when ac is switched on . The mechanic found a temporary solution by increasing the rpms manually. us ne engine ke rpms ziada kar diay ta k ac per band na ho. lekin is se permanent rpm ziada rehtey hain.
any expertjo bataey k ga15 engine main kia koi sensor hota hai jo ac on honey per rpm barhata hai ya carby engine ki tarah is main by vacuum switch hota hai.
vacuum switch bi nae hai gari main. kun ke engine cd 17 se swap ker k ga15 dala hai.
urgent help needed plz

[Xulfiqar]

this function is controlled by the ECU - the A/C wiring goes to the ECU which then controls the idle rpm and also the cooling fan. There is no jugaar or shortcut, you need to completely wire up the ECU.

here is the thread you want

https://www.pakwheels.com/forums/electrical-wiring-battery-lights/183880-nissan-ga15de-ecu-wiring-help

for help - the IACV is the thing that controls idle rpm - further down the thread you will find how to connect the A/C to the ECU

[saaqie786]

thannx xulfiqar bhai. simple words main bataen k konsi wire kahan lagani hai. better if can post pics. .///////

[Xulfiqar]

you need to check trace wiring from the ECU to the IACV - make sure its connected - there is a brown wire in the IACV connector check that it has 12V when the ignition is switched on. If not you need to connect it - its other end would be near the ECU connector.

Go through the whole thread - its not just cut this connect that, Its a whole sequence. e.g. If your IACV is connected but your A/C is not wired to the ECU you will not remedy it. SO to make the whole thing work refer to the first page of the thread - it even has wiring diagrams in it showing what to connect.

Page 3 of that thread explains how to connect the A/C to the ECU and how to connect the radiator fans to ECU.

[saaqie786]

abi samajh main aa gaya....i will check n then tell u

[saaqie786]

i have connected the sensor with the ecm. now i am not understanding where to attach the a/c in the ecm and how??///////////////////reply plz

[Xulfiqar]

Its pretty nicely explained on page 3

[salaara579]

this function is controlled by the ECU - the A/C wiring goes to the ECU which then controls the idle rpm and also the cooling fan. There is no jugaar or shortcut, you need to completely wire up the ECU.
here is the thread you want
https://www.pakwheels.com/forums/electrical-wiring-battery-lights/183880-nissan-ga15de-ecu-wiring-help
for help - the IACV is the thing that controls idle rpm - further down the thread you will find how to connect the A/C to the ECU

Does it create some problem, Im also facing but every thing is fine

[Xulfiqar]

when everything is wired like it should you wont face any petty issues like this.

[star2]

aham aham..... you know when your ECU is connected up nicely your car won't stop and won't let you use pakwheels ... lol...

@Xulfiqar

Salaam Guru G

[Xulfiqar]

Walaikum Salam star...

hhahahaa - correct on the visit PW part.

[SER_GTR]

Another GA15 Victim

Happy Wiring And Multimetering ....!!

[SER_GTR]

thannx xulfiqar bhai. simple words main bataen k konsi wire kahan lagani hai. better if can post pics. .///////

Mere Bhai If Its That Simple....Every Electrician Would Be Wiring EFI's As They Wire Direct Fans :P...!

Try To Go Through Whole Topic From Start.....Grab Some Popcorns And Read Each Post And You Will Understand It All..!

COnsidering You Know Basics Of Electronics And Have Worked WIth +12v Wiring...!

[star2]

@saaqi786

get some tools man, you have to do a part of it yourself...electricians don't understand that much of an ECU wiring mostly.....so be prepared and when you are prepared...let us know

[saaqie786]

@star2 and xulfiqar bhaais
main ne iacv ko ignition switch k sath connect kar dia hai. ab us ki brown wire main switch on kerne per 12 volt aa rahey hain..
now the only problem:S:S:S
ye kaisey pata chlay ga k ecm ki wires ki numbering kaisey karni hai
or
41 wali green ya grey wire konsi hai
mujhey numbering ka pta nahi chal raha...if any one can show me diagram
ab mujhey ye bataen k kia ab sirf main ne ac switch ki positive wire ecm main lagani hai??
kunke iacv main current aa rahi hai or wo ecm se signal bhi le raha hai switch on karney per
aik aur baat
main ne tukkey se ecm ki aik green wire main ac ka switch connect kia..but rpm decreased.......not increased
ab simple words main samjha den k ab kia karooon
i have all tools like wire cutter, meter etc..........
nd at least i have the basic knowledge of 12 v wiring,,,,

[SER_GTR]

Xulfi Bhai Got A JOB :P..

[star2]

Xulfi Bhai Got A JOB :P..

hahaha correct said.

@saaqie786

as suggested many times by senior members, please read that topic very very carefully, actually do a research on it and find mistakes in it, lol.

coming to the point, there is a block on the second page which is your ECU pinout, i think it is under the power steering oil pressure switch wiring diagram. check it. It is your ECU pinout. You will get what you want.

[star2]

and by the way, first connect your ECU with your chabi switch in correct way.

Look, there are four points in your chabi switch.

1st: Off
2nd: Acc
3rd: Ignition aka ON
4th: Start aka sulph at which starter motor operates ok.

Now, here first check whether your ECU starting relay is wired with your ECU or not. Common practice by stupid yard walas is they just assume it an extra accessory and pull out. The relay I am talking about can be seen in the 1st picture of topic.

Secondly, assuming the relay is present and wired correctly as well, and assuming your wiring is untouch and not cut wiring, you need to give ECU both "Ignition" signal and "Start" signal.

For that, you will get three wires of the same guage as in your chabi switch grip and make an extension of "Ignition", "Start", and "Battery +12V" till where your ECU is. You can also do reverse and extent your ECU wires up till chabi switch, but that will be confusing for you so, you just for the time being supply ECU with these wires first.

[saaqie786]

@star2 plz drop here your contact number or sms me on 0321-8500607

[pwuser156587870760]

Assallam o Alaikum xulficar bhai can I get your mobile number? To know about Ac wiring of Ga 15 with ecu?