How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Chris (aka- Moose) Your Own Question
Chris (aka- Moose)
Chris (aka- Moose), Pontiac Technician
Category: Pontiac
Satisfied Customers: 47310
Experience:  16 years of experience
Type Your Pontiac Question Here...
Chris (aka- Moose) is online now
A new question is answered every 9 seconds

I have a 2008 Grand Prix that I need help on getting the AC

Customer Question

I have a 2008 Grand Prix that I need help on getting the AC to work.
Submitted: 1 year ago.
Category: Pontiac
Customer: replied 1 year ago.
Thought it was just low on Freon. Hooked up the gauges and it has over 100 psi at about 75 deg F. Started looking at the electrical side. Checked the fuses all good and checked relay in the underhood fuse box. Swapped relay with one from another Grand Prix and nothing. Checked voltage at E7 terminal at fuse block and it is battery voltage. Turned on ignition and checked voltage at E8 terminal and it is battery voltage. Installed jumper wire between E7 and E8 pins and AC compressor runs. Installed new AC pressure switch and still nothing. Beginning to think that the PCM is not telling the relay to energize. I have a Actron CP9185 scanner but I do not think it will give the PID's or the DTC's for the HVAC. Is there any way I can verify if the PCM is getting a signal to energize the AC from the HVAC module or if the PCM is sending a signal to the AC.
Customer: replied 1 year ago.
Sorry the final line should read .....if the PCM is sending a signal to the AC comp relay.
Expert:  Chris (aka- Moose) replied 1 year ago.
The HVAC and PCM communicate with each other over the data wires. So there is not a wire test you can perform with a meter. A scan tool is the only way to check if the signal is being sent. Normally if the HVAC screen shows the AC commanded on, but the relay is not getting grounded then its the PCM to blame. You want a excellent 5 star answer & I would like to be rated the same for providing it. Consider I don't know your skill level & I can't see, smell, hear, or touch the vehicle. It may take a few back and forth replies. Try your best to respond with good detail so I can do the same. I normally log in at 3pm and work late. A rating is required. Your rating me, what I type. I am not an employee of this website, nor have control over the fees or the time it took to get a response. If you rate negative or not at all you still paid, but I get nothing. I want you pleased with me and my efforts, so let me know if your experience here has come up short.Thanks Chris
Customer: replied 1 year ago.
I also have a 2006 Grand Prix. Would it be possible to switch the PCM's between the two to see if the issue follows the PCM. Then I would put the PCM back into the original vehicle.
Expert:  Chris (aka- Moose) replied 1 year ago.
Its worth a try but odds are its not going to start from the anti theft system