chevnut55

I am using a c5 pcm and have nothing coming out of the tach wire.
Also the a/c request does nothing tried pos and neg.
I tried everything I know and asked the tuner to check on it but not sure if he did, just said must be wired wrong but I checked it at the pcm and wiring is not the problem.
I need to get it fixed asap, What do I look for?

MontecarloDrag

iTrader: (3)

More information is needed.
Is it an engine swap? Which tach are you trying to hook?
What tuning software are you using?

A/C request must be changed in the tune to 12V logic. By default it is Class 2 signal from HVAC module, sending 12V to the PCM does nothing even if wired correctly.

chevnut55

Thanks for responding.
Is a ls1 swap into a 69 Camaro with a factory tach. The motor is a 2000 c5 vette and stock pcm with a dieted harness and a vintage air kit.
That my big problem is I do not know anything about tuning, I brought the car to slowhawk once and the pcm once, but not sure if he knows about this kind of stuff and want to get it working before I bring the car to him to dyno and hopefully make run good. because it runs like crap now.
The 1st tune was done by bp auto 2 times and kept getting worse , but he supposedly changed the tach signal and he added a ac request wire with the harnes but nothing works on either, slowhawk says the pcm program was messed up and doest not think it was wired correct but it is if it was not the tach module probely would not work.
Can I get a tach signal off the tack mod?
Also Exactly what needs to be done to the tune to fix the problems so I can tell him what needs to be done.
I do not know if slowhawk cares about the tach and ac stuff, but just making it run good and faster so If I ask him do fix these problems and doesn't or can not I need to bring it to someone who can.

MontecarloDrag

iTrader: (3)

A good tuner can make your car working like new. I have done quite a few like yours and everything can be done.

Slowhawk has a good reputation here, I suggest you take the car to Him and listen to His advice. Let him do the work as He wants and give Him time, this things take time to fix specially if they weren't done right the first time.

Lextech

iTrader: (18)

Can you elaborate on this. Where is that parameter? I have looked for that setting on 3 different softwares and am not seeing it.

Jeff

chevnut55

I brought the car to him already and rather try to fix any problems before I wase his time and my money.
Im getting 3 engine codes p 0654 engine rpm output circuit, p 0481 fan 2 control circuit and p 0327 bank 1 knock low output
Is my a/c request suppose to be ground to the pcm as I was told or should I switch it back to pos and what wire should I use for the tach? I was told the t/c wire works,
I want to get everything straight on my end before I even call slowhawk.

Pacer Racer

iTrader: (6)

To the best of my knowledge only tunercat supports changing it.
Its in the same system pull down as the fan settings and the Vats

Pacer Racer

iTrader: (6)

PM goast69 on here he went through it all with a 69 Camaro, he will also tell you the vintage air setup for those cars is junk