g1 gts ac and cold start

[Lee Mackenzie]

I have a R33 gtst with a link g1 gts ecu, i had an issue with the ignition not shutting down and tracked it to pin 9 on the ecu having a constant 12+ output, where it should be a 12v- switched out put, i cant find anything in the software and ecu mapping where i can switch the polarity of the ac clutch trigger, (I know with the g4 ecu i can switch between high and low polarity) .

any ideas on how i can solve this problem as i would really like to get my ac working.

other issue i have is on cold start it will hold 1500 rpm for 30 mins + until it finally drops to idle, i have not been able to find any duration or temp setting for cold start only a % setting which is supposed to drop after the engine reaches 50 deg C.

any help towards solving these issues would be greatly appriciated

thanks Lee

[Scott]

Hi Lee,

Pin 9 on your ECU is an aux output, it will have 12v + present when it is not switched.  I believe pin 46 should be the input into the ECU for your A/C, are you getting a signal on this pin? Neither of these pins should have any effect on your ignition system, if you break the connection to pin 9 does it stop your ignition problem?

With your idle issue, it sounds like your idle base position may be too high. You should have an 'idle hot' and an 'idle cold' setting, try lowering these.

Scott.

[Lee Mackenzie]

Hi Scott

thanks for the reply, input signal is fine the ecu compensates for ac load, pin 9 is ecu ouput to the ac comp clutch relay, which has an ign 12+ to it and requires a 12v switched to activate the relay, i currently have pin 9 backed out and my ign turns off fine, with pin 9 connected the engine will stop when the ign is switched off but all my dash lights and thermofan, heater etc keep running, somtimes it would shut down after a few seconds other times it wouldnt shut down untill i restarted the engine and tried again.

Pin9 aux3/ac clutch is feeding positive to the relay when the relay requires neg, i know with the G4 i can switch the polarity but i cant even find anything in the software on the g1 that even refrences the ac except for enrichment.

i am thinking that my ecu may have issues as i cannot set tps span, the command is there in offline mode, but with the ign on engine not running and connected to ecu the tps set function dissapears, also i loose communication with the ecu after about 10 mins,( have to leave the car off for about an hour then i can connect again.)

the board on the ecu says gts194, from what i can find its a G1 but i may be mistaken

Thanks

Lee

[Scott]

Hi Lee,

It sounds like you definitely have a back feeding issue. I take it that it all used to work fine? It could be a faulty ECU. If you are interested in having it checked email [email protected]

Cheers,

Scott.