Goodman GMEC960803BN Error Code Amber 4 Flashes: Y Present With No G Call, Y1 Present With No G Call
What Does Code Amber 4 Flashes Mean?
Four amber flashes on the Goodman GMEC960803BN's Integrated Control Module mean the board is receiving a Y or Ylo (cooling) call with no G (fan) call present. During cooling, the indoor blower must run, so the thermostat is supposed to energize G together with Y. A cooling signal without the fan signal is an invalid combination, and the board will not operate.
On a correctly wired system, a call for cooling always brings the G fan signal with it. When G is missing, the wiring or thermostat is at fault — a G wire that is loose or landed on the wrong terminal, or a thermostat that is not sending the fan output with the cooling output. A failed thermostat can also produce this.
This is a low-severity signal-validation fault, not a safety issue, but it stops cooling operation. It is the cooling-side counterpart to amber 3 flashes, which flags the invalid heating combination (a W2 second-stage call with no W1 first-stage call).
What You'll Notice
- The air conditioner will not run even though the thermostat is set to Cool and calling
- The control board flashes amber four times
- The problem often appears after a thermostat replacement or wiring change
- The blower does not start on a cooling call
- The outdoor unit may not engage because the furnace board rejects the invalid signal
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Improperly connected thermostat wires | Most common | ✗ Call a pro → |
| Faulty thermostat | Common | ✗ Call a pro → |
How This Is Diagnosed
Because the board reports a Y-without-G signal, diagnosis targets the thermostat and its wiring. A technician confirms the thermostat is configured correctly and checks that the G (fan) wire is landed and continuous between the thermostat and the furnace board, along with the Y/Ylo cooling wires. If the wiring is correct but G still does not appear during a cooling call, the thermostat is suspected and tested or replaced.
When to Call a Professional
This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:
- The code appeared right after a thermostat replacement or rewiring
- You are not comfortable checking the G (fan) and Y (cool) terminal connections
- The wiring appears correct but the four amber flashes persist
- The thermostat behaves erratically, suggesting it has failed
Frequently Asked Questions
What does Y present with no G call mean?
It means the furnace is receiving a cooling signal without the required fan signal. Cooling needs the blower, so the board treats Y without G as invalid and will not run — usually a wiring or thermostat problem.
My AC stopped working after I changed the thermostat — could this be why?
Yes. A missing or misconnected G (fan) wire after a thermostat swap is a common cause of four amber flashes. The G and Y wiring and the thermostat configuration should be rechecked.
✓ Verified against manufacturer service manual — March 2026