Ameristar mini split error code P2
Over-current protection.
- TypeProtection
- SystemPower supply
- Can I fix it?Homeowner checks, then maybe a tech
What P2 means on a Ameristar
The outdoor unit's total current exceeded its limit and it shut down.
On this platform, P2 is a protection: the system stopped or throttled itself to prevent damage; many clear on their own once conditions return to normal.
Common causes
- A dirty outdoor coil or failed fan.
- Low supply voltage.
- A refrigerant overcharge.
- A failing compressor.
How to fix it yourself
Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician.
- Look at the outdoor unit: clear leaves, cottonwood fluff, snow or ice from the coil and make sure the fan can spin freely and nothing is stacked against the cabinet.
- If you own a multimeter and are comfortable using it, measure the supply voltage at the outdoor unit's L1 and L2 terminals with the unit running. A 230 V system should read roughly 208 to 253 VAC.
- Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.
When to call a technician
If the coil is clean and voltage is normal, a technician should check compressor current.
Which Ameristar units show P2
This page applies to Ameristar M4TXK / M4MXW hi-wall inverter units. Ameristar's own documentation lists P2 as "Over-current protection", the same definition used across the TCL platform it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.
Where Ameristar shows this code
The indoor display shows the code in place of the set temperature. E codes are faults: something has failed and needs diagnosis. P, H, d and F codes are protections: the system stopped or throttled itself to prevent damage, and many clear on their own once conditions return to normal.
Other Ameristar codes
Same part of the system as P2:
P2 on other brands
The same characters do not always mean the same thing. Check the brand on your unit.
- Pioneer P2 High temperature protection (compressor top or inverter module) / Low pressure protection (outdoor display)
- Blueridge P2 High temperature protection (compressor top or inverter module)
- Zone Air P2 Over-current protection
- Mitsubishi Electric P2 Indoor pipe (liquid) temperature sensor fault (open or short circuit)
- Trane P2 Over-current protection / Indoor pipe (liquid) temperature sensor fault (open or short circuit)
- ACiQ P2 High temperature protection (compressor top or inverter module) / Over-current protection
Questions people ask
Can I reset a Ameristar P2 code myself?
Yes. Turn the system off at the breaker for five minutes, then restart it. If P2 comes back, the fault is real and needs the checks above.
Is it safe to keep running a Ameristar showing P2?
Not repeatedly. A protection code means the unit stopped itself to prevent damage, and resetting it over and over can turn a cheap repair into a compressor failure. Reset once, check the basics, and stop if it returns.
Do I need a technician for Ameristar P2?
Work through the checks below first; they resolve most cases. If they do not, the repair itself may need a technician. If the coil is clean and voltage is normal, a technician should check compressor current.
Sources
- Trane Mini Split HW Inverter Service Manual (4TXK / 4MXW), SVM027A-EN, 2024, error code table
Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.