What does it mean?
P1464 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: A/C Control Signal Circuit Malfunction (Self-Test) .
Symptoms
- Code stored after a key-on or running self-test, with the MIL possibly on
- A/C runs when it should not, or refuses to run at all
- Idle speed does not step up when the A/C is switched on
- Cooling fan runs whenever the key is on
- Noticeable idle change every time the A/C switch is used
Likely causes
- A/C or blower left switched on while the self-test was being run, which is by far the most common trigger
- A/C demand wire shorted to power or to ground
- Faulty A/C control head switch, or a clutch cycling pressure switch stuck closed
- Open in the demand circuit between the switch and the PCM
- Corroded connector at the PCM or at the climate control head
- Failed clutch cycling pressure switch reporting a constant request
- PCM input circuit fault
How to fix it
- Repeat the self-test with the A/C and blower fully switched off; in many cases the code does not return
- Watch the A/C request parameter on the scan tool while a helper cycles the switch
- Inspect the control head, the cycling pressure switch and their connectors
- With the switch disconnected, test the demand circuit for shorts to power and to ground
- Check continuity from the switch connector through to the PCM pin
- Repair the wiring or replace the failed switch
- Clear the codes and rerun the self-test to confirm the repair