I have a 98 Catera the check engine light is on and i took it to Autozone and received the trouble code p0508. Says me voltage signal for the electrical circuit of the idle control system is too low. I changed the air filter, put in some fuel injection cleaner and is still on. MY question is could it be the a/c compressor? Because the air conditioner doesn't work either. I know that a/c compressor can have an effect on the idle system.

 

I don't show a P0508 listed for 98 catera???

 

this everything that was on the sheet
Troublecode OBDII (Alpha) P Code
Troubleshooting P0508
The PCM has determined that the voltage signal for the electrical circuit of the idle control system is too low for the current engine operating conditions.

 

Thats weird. i checked 97, 98 and 99
There is a 505, 506 and 507 but no listing for a 508.
They all deal with the idle circuit but without a detailed explanation of the code failure conditions i could only guess at what was causing the light.
Sorry i can't help more.

 

Does the low voltage mean low idle?
If you AC compressor was bad and loading down the system, that might cuase a low idle.
Do you have a serpentine belt, or can you isolate the compressor?


Dave