4 amber flashes Cooling call (Y) without fan call (G)

What the control is telling you

The board is getting a Y signal with no G signal. Heating and cooling still work but this warning shows to flag a wiring problem.

Applies to: York/JCI residential gas furnaces: York UTEC IFC furnaces, York White-Rodgers IFC furnaces, York TM9V

Likely causes

• G wire not connected at thermostat or board
• Thermostat not configured to send G with Y
• Broken G conductor

Test and repair steps

1. Check that the thermostat G terminal is wired to G on the furnace board.
2. Check thermostat setup so the fan output follows a cooling call.
3. Repair the wire and confirm the code clears.

Settings for these units

Clearance to combustibles · York TM9V

Leave about 24 in. at the front and 18 in. at the side for service.

Approved for alcove and attic installs.

Filter size by return location · York TM9V

Sizes assume high velocity filters (600 FPM); throwaway filters must stay at or below 300 FPM.

Filters go outside the cabinet - never inside the furnace.

Models that show this code

7 models in York UTEC IFC furnaces, York White-Rodgers IFC furnaces, York TM9V

Other codes on the same units

• 2 red flashes Pressure switch closed when it should be open
• 3 amber flashes W2 call without W1
• 3 double red flashes Second-stage pressure switch not closing
• 3 red flashes Pressure switch open when it should be closed
• 4 red flashes Main limit switch open
• 5 red flashes Rollout switch open / limit circuit open over 15 min
• 6 red flashes Pressure switch cycling lockout
• 7 red flashes Ignition failure lockout (retries)