HVACopediaTrane · Air handler
E12 Control fuse open
What the control is telling you
The 5 A fuse on the IMBC is open.
Applies to: Trane P0V0 modular blowers (P0V0A/B/C/D)
Likely causes
- Short in thermostat/outdoor wiring
- Overloaded 24 V circuit
Test and repair steps
- Look for shorted low-voltage wiring.
- Replace the 5 A fuse.
- Measure 24 V current draw before returning to service.
Settings for these units
Return filter size by cabinet width · Trane P0V0
| Cabinet width | Filter |
|---|---|
| 14-1/2 in. | 1 - 14 x 25 x 1 in. |
| 17-1/2 in. | 1 - 16 x 25 x 1 in. |
| 21 in. | 1 - 20 x 25 x 1 in. |
| 24-1/2 in. | 1 - 24 x 25 x 1 in. |
No filter inside the unit - remote/duct filter required.
Over 1600 CFM needs dual returns.
Models that show this code
4 models in Trane P0V0
Other codes on the same units
- E01 Blower control (IMBC) internal failure
- E6.1 120 V polarity reversed
- E6.2 Ground not detected
- E13 Blower HP / OEM ID mismatch
- E14 No personality module and local copy bad
- E15 Unit data file corrupt in module and control
- E17 Blower motor not responding
- E18 Blower communication failure on the control side
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Source: Trane 18-GE20D1-1E-EN (P0V0 installer's guide) - section IMBC Display Codes, Error Codes. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.