24VNA6 / 25VNA4 seriesCarrier 65 fault code (24VNA6 / 25VNA4)
EXV-VI Phase Open; EXV-VI Power Short to Ground; EXV-VI Phase Short to Ground
What the manual says
EXV-VI Phase Open; EXV-VI Power Short to Ground; EXV-VI Phase Short to Ground
| Fault | Malfunction | Description |
|---|---|---|
| — | 41 | EXV-VI Phase Open |
| — | 44 | EXV-VI Power Short to Ground |
| — | 45 | EXV-VI Phase Short to Ground |
Models and series
Listed for: 24VNA6, 25VNA4.
Troubleshooting from the service manual
Code 65-41 EXV-VI Phase Open Lockout
Applies to 5T AC and HP only. EXV-VI is required to operate the vapor injection circuit which is used in high demand situations such as high ambient cooling or low ambient heating. Once per day the EXV-VI will test itself by operating to a known position as the valve does not have the capability to feedback actual position. The PCM software must know the starting point and then count when stepper motor is pulsed. The valve will remain closed until additional capacity is needed. This code occurs when the PCM determines the resistance of the stepper motor coil circuit is above the maximum value to properly function. Inspection of the wire harness and plug should be performed, as well as using multimeter to confirm "open" continuity between pins. If nothing is found, replace coil and harness assembly.
24VNA6-25VNA4-1SM, p. 20
Code 65-44 EXV-VI Power Shorted Lockout
Applies to 5T AC and HP only. EXV-VI is required to operate the vapor injection circuit which is used in high demand situations such as high ambient cooling or low ambient heating. Once per day the EXV-VI will test itself by operating to a known position as the valve does not have the capability to feedback actual position. The PCM software must know the starting point and then count when stepper motor is pulsed. The valve will remain closed until additional capacity is needed. This code occurs when the PCM determines the EXV power supply is drawing excessive current. The most likely cause of this fault is the wire attached to pin 1 of EXV-H connector being shorted to ground. Inspection of the wire harness and plug should be performed, as well as using multimeter to confirm "short to ground" continuity. If nothing is found, replace coil and harness assembly.
24VNA6-25VNA4-1SM, p. 20
Code 65-45 EXV-VI Phase Shorted Lockout
Applies to 5T AC and HP only. EXV-VI is required to operate the vapor injection circuit which is used in high demand situations such as high ambient cooling or low ambient heating. Once per day the EXV-VI will test itself by operating to a known position as the valve does not have the capability to feedback actual position. The PCM software must know the starting point and then count when stepper motor is pulsed. The valve will remain closed until additional capacity is needed. This code occurs when the PCM determines the EXV power supply is drawing excessive current. The most likely cause of this fault is one or more wires attached to pins 2-5 of EXV-H connector being shorted to ground. Inspection of the wire harness and plug should be performed, as well as using multimeter to confirm "short to ground" continuity. If nothing is found, replace coil and harness assembly.
24VNA6-25VNA4-1SM, p. 20
Source
24VNA6-25VNA4-1SM, p. 26
65 | | 41 | EXV-VI Phase Open | | 44 | EXV-VI Power Short to Ground | | 45 | EXV-VI Phase Short to Ground
Last checked 2026-10-18 against 24VNA6-25VNA4-1SM.
Safety: disconnect power before opening the unit. Gas, high voltage and refrigerant work belongs to a licensed technician.