Goodman Air Conditioner Error Codes List: Every Code Explained
Every Goodman air conditioner error code we could verify against Goodman's own documentation — what it means, what usually causes it, and the first fix to try — in one table. Codes differ between model series, so treat your model's tech sheet as the final word.
How to read and retrieve error codes on Goodman air conditioners
On a communicating Goodman the diagnosis lives outdoors: the integrated control module's 7-segment LED (DS1/DS2; DS3 is not used) displays the two-character code, and on a fully communicating system the same fault is mirrored as a scrolling message on the ComfortNet thermostat ('Check Air Handler'/'Check Outdoor' family, with the thermostat-only message code — LOW SIDE FAULT for 01, HPS for the 02 lockout family, LOW VOLT for 09/L8/H8, INVALID CONFIG for d3). Goodman's troubleshooting tables are organised by symptom first ('compressor and outdoor fan are off', 'air conditioner/heat pump may appear to be operating normally') because several codes — the voltage family especially — stand while the unit seems to run fine. Two reading habits matter. First, read the code before cycling power: a 24 VAC cycle is also the lockout clear, so resetting first destroys the evidence of which lockout you had. Second, remember the display's blind spot: a non-communicating Goodman condenser has no display at all, so 'no code' on a GSX-class unit means 'no reporter', not 'no fault' — those units are diagnosed by symptom, gauge and meter, exactly as their service literature does it.
The complete Goodman air conditioner error code list
| Code | Meaning | Most likely cause | First fix |
|---|---|---|---|
| 01 | Low pressure cut-out trip / low side fault — the low pressure switch has opened (ComfortNet thermostat message: LOW SIDE FAULT / LPS OPEN). Goodman also shows 01 for four consecutive compressor protector trips with average run time between trips greater than 3 hours | Low refrigerant charge, a restriction in the liquid line, indoor blower motor failure, or the indoor thermostat set extremely low (Goodman's listed causes) | Check the indoor filter and that the indoor blower runs; the fault clears after 30 consecutive normal cycles or by cycling 24 VAC to the control — but charge verification, restriction repair and switch replacement are certified-technician work. Three switch trips in one demand become lockout L1 |
| 02 | High pressure cut-out trip / high side fault — the high pressure switch has opened (also shown after four consecutive compressor protector trips with average run time between 1 and 15 minutes, with both pressure switches closed) | Blocked condenser (outdoor) coil or an outdoor fan not running (Goodman's listed causes) | Clean the outdoor coil and confirm the outdoor fan runs, its wiring is sound and its capacitor is good. The fault clears after four consecutive normal cycles, or by cycling 24 VAC to the control. Three switch trips in one demand become lockout L2 |
| 03 | Short cycling — run time for the last 4 cycles was less than 3 minutes each, with the compressor protector untripped and both pressure switches closed (ComfortNet message: SHRT CYCLE / CMPR 03) | Intermittent thermostat demand, or a faulty compressor relay (Goodman's listed causes) | Check the thermostat and its wiring and the compressor relay operation; replace the control if the relay is faulty (Goodman's stated actions). The fault clears after 4 consecutive normal cycles or by cycling 24 VAC. Note: Goodman's minimum compressor run time was changed from 30 seconds to 3 minutes, which is the threshold this code measures |
| 04 | Locked rotor — the control has detected a compressor locked-rotor condition (four consecutive compressor protector trips with average run time between trips under 15 seconds) | Compressor bearings seized, a failed compressor run capacitor, faulty run capacitor wiring, or low line voltage (Goodman's listed causes) | Technician work: check compressor operation and the run capacitor, repair wiring, and verify line voltage is within the rating-plate range (contact the utility if it is out of range). Must be cleared by cycling 24 VAC to the control — after the cause is fixed, not instead of fixing it |
| 05 | Open circuit — the compressor circuit is open; power has been disconnected for 4 hours or more in Goodman's symptom wording, with both pressure switches closed | Power disconnected, a failed compressor protector, or the compressor not properly wired to the control (Goodman's listed causes) | Check circuit breakers and fuses and the wiring to the unit and compressor; repair/replace as needed (Goodman's stated actions). The fault clears after 1 normal cycle or by cycling 24 VAC to the control |
| 06 | Open start circuit — current is present in the run circuit but not in the start circuit | Compressor start winding open, a failed compressor run capacitor, faulty run capacitor wiring, the compressor not properly wired to the control, or faulty compressor wiring (Goodman's listed causes — the start path is proven through the run capacitor circuit on these controls) | Technician start-circuit diagnosis: compressor, run capacitor and wiring. The fault clears after 1 normal cycle or by cycling 24 VAC. Four detections with a 5-minute delay between each become lockout L6 |
| 07 | Open run circuit — current is present in the start circuit but not in the run circuit | Compressor run winding open, the compressor not properly wired to the control, or faulty compressor wiring (Goodman's listed causes) | Technician diagnosis as for 06. The fault clears after 1 normal cycle or by cycling 24 VAC. Repeated detections become lockout L7 |
| 08 | No line voltage — the control detects no line voltage at the unit | Disconnect open, breaker tripped, or supply wiring to the outdoor unit interrupted | Check the outdoor disconnect and breaker and verify the unit is connected to the power supply on its rating plate; supply-wiring faults are electrician/technician work |
| 09 | Low pilot voltage — the control detects secondary (24 V) voltage below 18 VAC (ComfortNet message: LOW VOLT) | A control transformer overloaded, or low line voltage dragging the secondary down (Goodman's listed causes) | Check the fuse and the transformer and correct the low secondary voltage condition (Goodman's stated actions). The fault clears if secondary voltage rises above 21 VAC. A control starved of pilot voltage misbehaves in ways that imitate board failure |
| A2 | Outdoor air temperature sensor fault (ComfortNet message: OUTDOOR AIR TEMP SENSOR FAULT / AIR FLT; the thermostat displays '---' in its temperature area) | Shorted sensor, open sensor, sensor disconnected, or a sensor reading out of range (Goodman's listed causes) | Check the sensor connection and replace an open/shorted sensor with the correct replacement part (Goodman's stated actions). Power OFF before repair |
| E5 | Open fuse — the control's low-voltage fuse has opened (ComfortNet message: LOWV FUSE / FUSE OPEN) | A short in the low-voltage wiring (Goodman's listed cause) | Locate and correct the short first, then replace the fuse with a 3-amp automotive type (Goodman's stated actions). Power OFF before repair. A fuse replaced into a live short opens again |
| EE | Board misoperation — the integrated control module has an internal fault (ComfortNet message: INTERNAL FAULT) | Compressor relay contacts welded, or an internal failure of the control module (Goodman's listed causes) | Replace the control module with the correct replacement part, power OFF before repair (Goodman's stated action) |
| H8 | High line voltage — the control detects line voltage greater than 255 VAC. The unit may appear to be operating normally and the compressor protector may be open while H8 stands | Utility supply voltage too high, or the unit connected to a supply above its rating plate | Correct the high line voltage condition and contact the local utility if needed; verify the unit is connected to the power supply on its rating plate (Goodman's stated actions). The fault clears if line voltage decreases below 255 VAC |
| L1 | LPCO lockout — the low pressure switch has tripped three times within the same thermostat demand, and the control has locked the compressor out | The code 01 family persisting: low refrigerant charge, liquid-line restriction, indoor blower failure or an extreme thermostat setting | Must be cleared by cycling 24 VAC to the control — but only after the 01 cause is fixed (charge verification, restriction repair, blower and switch checks, per Goodman) |
| L2 | HPCO lockout — the high pressure switch has tripped three times within the same thermostat demand | The code 02 family persisting: blocked condenser coil or a dead outdoor fan most often | Clean the coil, prove the fan, motor wiring and capacitor, then clear by cycling 24 VAC to the control; a lockout cleared without its cause returns on the next demand |
| L6 | Open start circuit lockout — the open-start-circuit condition (06) has been detected 4 times with a 5-minute delay between each detection, and the control has locked out | A failed run capacitor, open start winding, or open start-circuit wiring that did not heal between attempts | Technician start-circuit repair before the lockout is cleared by cycling 24 VAC; repeated locked-rotor-style starts damage compressors |
| L7 | Open run circuit lockout — the open-run-circuit condition (07) has repeated into lockout (4 detections, 5 minutes apart, per the 06 pattern Goodman documents for this lockout family) | Open run winding, compressor not properly wired to the control, or faulty compressor wiring | Technician diagnosis as for 07, before clearing the lockout by cycling 24 VAC |
| L8 | Low line voltage — the control detects line voltage less than 185 VAC. The unit may appear to be operating normally and the compressor protector may be open while L8 stands (the voltage counterpart of 09's low pilot voltage) | Utility sag, a failing disconnect/contactor, or supply wiring dropping voltage under compressor load | Check circuit breakers and fuses, verify the unit is connected to the rating-plate supply, correct the low line voltage condition and contact the local utility if needed (Goodman's stated actions). The fault clears if line voltage increases above 185 VAC. Compressors started on low voltage overheat |
| P0 | Compressor protector open — the compressor's protector has opened while a demand is present. NOTE: in RS6200007's LED list P0 is NOT marked heat-pump-only (the heat-pump-only codes are A3, dF/dt/dE and P1/P2/P3), and its troubleshooting row is worded 'Air conditioner/heat pump' — P0 applies to Goodman air conditioners as well | Goodman's listed causes: current not passing through the run or start windings, compressor run winding open, compressor not properly wired to the control, faulty compressor wiring, a failed compressor run capacitor, or faulty run capacitor wiring | Technician work: check the compressor, its wiring and the run capacitor, repair/replace as needed. The fault clears after 1 normal cycle or by cycling 24 VAC to the control |
| b0 | No indoor airflow — the circulator blower motor is not running when it should be (fully communicating systems only; ComfortNet message: MOTOR NO RUN) | Indoor blower motor problem, or a communication error between the indoor and outdoor units (Goodman's listed causes; the heat-pump sibling file's 'welded compressor relay' wording belongs to the EE row, not this one) | Check the indoor blower motor, its wiring and the indoor unit control; repair/replace faulty wiring, motor or control (Goodman's stated actions) |
| b9 | Inadequate airflow — indoor airflow is lower than demanded (fully communicating systems only; ComfortNet message: LOW ID AIRFLOW). The system runs at reduced performance — low stage when high stage is expected | An indoor blower motor problem, blocked filters, restrictive or undersized ductwork, or an indoor/outdoor unit mismatch (Goodman's listed causes) | Check/replace filters, check ductwork and resize as needed, and verify the indoor and outdoor units are a properly matched, approved combination against the specification sheets (Goodman's stated actions) |
| d0 | Data not yet on network — the integrated control module does not contain any shared data (fully communicating systems only; ComfortNet message: NO NET DATA) | The unit is wired as part of a communicating system but its shared data set was never populated | Verify the system type and populate the shared data using the memory card for the specific model (insert the card BEFORE turning power on; the error clears once data is loaded), or wire the system as a legacy system (Goodman's stated actions) |
| d1 | Invalid data on network — the control module contains invalid shared data, or network data is invalid for the control module (fully communicating systems only) | Wrong or corrupted shared data loaded for the model | As for d0: verify system type, populate the CORRECT shared data for the specific model by memory card, or wire as legacy. The error clears once valid data is loaded |
| d2 | System mismatch — the outdoor unit requires airflow greater than the indoor unit's airflow capability, or shared data is incompatible with the system or missing parameters (fully communicating systems only) | An indoor/outdoor pairing whose airflow requirements do not match, recorded in the shared data | Verify the shared data is correct for the specific model and repopulate if required; the underlying fix is a properly matched system — see the specification sheets for approved matches and airflow requirements |
| d3 | Configuration mismatch — the shared data sent to the integrated control module does not match the hardware configuration (fully communicating systems only) | Shared data for a different hardware configuration than the equipment actually installed | As for d2: verify system type and shared data for the specific model, repopulate if required, or wire as legacy. The error clears once correct data is loaded |
| d4 | Invalid memory card data — the shared data on the memory card has been rejected (fully communicating systems only; ComfortNet message: INVALID MC DATA) | A memory card whose data does not belong to this model/control | Use the memory card for the specific model and repopulate; a rejected card is the control protecting the system from wrong data, not a board failure |
How to reset / clear error codes on Goodman air conditioners
Goodman codes clear the way their own tables say, and the tables distinguish three endings. Simple faults (01, 02, 03, 05, 06, 07, P0) clear themselves after a stated number of consecutive normal cycles — four for the pressure family, one for the circuit family — or can be cleared by cycling 24 VAC to the control. Lockouts (L1, L2, L6, L7) do NOT self-clear: Goodman's wording is that the fault 'must be cleared by cycling 24 VAC to the control', and that instruction assumes the cause has been repaired first, because a lockout cleared into a standing cause re-counts its three trips and locks out again on the same demand. Voltage faults (09, L8, H8) clear when the voltage itself returns inside its band (secondary above 21 VAC, line above 185 VAC or below 255 VAC respectively). The shared-data family (d0-d4) clears when the correct shared data is loaded by memory card — the card goes in BEFORE power is turned on, and may be removed after the data loads, with power off for removal. Across every family, Goodman's standing caution heads the repair columns: turn power OFF prior to repair, and replace parts with the correct replacement part.
How to diagnose any Goodman air conditioner code
Work the problem in this order — and stop where refrigerant, compressors or mains wiring begin, because those are licensed work: (1) record the code exactly as displayed, including whether it came from the indoor display, the wired/wireless remote check mode, or an LED pattern on the outdoor unit — the three are different reports; (2) check the homeowner basics first: the air filter (a matted filter ices coils and imitates sensor and refrigerant faults), the condensate drain and float switch, the outdoor coil clear of leaves and debris, and both breakers fully on; (3) power-cycle once at the breaker, then run the mode the code interrupted and watch the sequence — indoor fan, outdoor fan, compressor start — because the stage that never starts names the fault family; (4) on mini-splits, retrieve the stored check code with the remote's diagnosis function before clearing anything, and write down the full code including its letter family; (5) a code that returns in the same mode is an active fault. Refrigerant charge, sealed-system and board-level work is professional work — an undercharged system re-iced after a reset is being damaged, not cured.
The Goodman AC that has no codes: ComfortNet displays, the silent GSX fleet, and the furnace lists that do not belong here
Ask for 'Goodman air conditioner error codes' and the internet will hand you flash counts — one flash, two flashes, five flashes — with total confidence. Open Goodman's own service literature and a different picture emerges, in two halves. The first half is the communicating fleet: ComfortNet condensing units (ASXC, DSXC, GSXC) whose outdoor control — Goodman's PCBHR104/105 — carries a real 7-segment LED display and reports real two-character codes, mirrored as plain-language messages on the ComfortNet thermostat. That fleet has a rich, documented fault language, and it is the table on this page. The second half is the fleet most Goodman air conditioners actually belong to: the non-communicating GSX-class condensers, single-stage workhorses with no outdoor fault display at all. Their service manuals troubleshoot by symptom — pressures, temperatures, current draws — and publish no code table, because there is nothing on the unit to display a code with. So where do the flash lists come from? From the other appliances in the same cabinet family tree: Goodman furnaces genuinely do report by LED flash counts, and Copeland Comfort Alert modules genuinely do flash compressor alerts on some equipment — and content sites copy those tables onto air-conditioner pages wholesale. The tell is always the same: the list never names the control that is supposedly flashing. On a Goodman AC the honest first question is not 'what does the code mean' but 'which control is reporting' — a 7-segment display outdoors means read this page's table; no display means there is no code, the diagnosis is a symptom diagnosis, and anyone quoting you a flash count for that unit is reading a furnace's diary aloud.
Trips, lockouts and the arithmetic of three: how Goodman's pressure family escalates
Goodman's pressure codes are a story told in counts, and reading only the final code throws away the plot. It begins with a trip: 01 when the low-pressure switch opens, 02 when the high-pressure switch opens. A single trip is the protection doing its job against a momentary condition — a filthy condenser on the hottest afternoon of the year, a charge that has been seeping away all season. Goodman's tables even give the trips a second author: four consecutive compressor protector trips with the wrong average run times between them are also reported as 01 or 02, because from the control's chair a compressor that keeps cutting out on its own protector is a pressure-family story until proven otherwise. The escalation is mechanical: three switch trips within the same thermostat demand convert the trip into a lockout — L1 for the low side, L2 for the high side — and the compressor is stopped until a human cycles 24 VAC to the control. The compressor-electrical family runs on a parallel counter: 06 and 07, the open start and run circuits, become L6 and L7 after four detections spaced five minutes apart. The diagnostic value is in the arithmetic. A unit found in L1 has told you its low-pressure switch opened three times in one demand — that is not a switch being dramatic, it is a circuit repeatedly reaching the switch's limit, and the cause list (charge, restriction, indoor blower) is short and testable. Resetting a lockout without working that list does not buy a fresh start; it buys exactly three more trips, each one running the compressor at the edge of its protection, followed by the same lockout. Read the trip code, fix the trip cause, then clear the lockout — in that order, every time.
The d-family and the memory card: when a Goodman 'fault' is really a data problem
Five of the codes on this page — d0, d1, d2, d3, d4 — do not describe anything physical that has broken. They describe information: the shared data that tells a communicating Goodman control what system it is part of. In a fully communicating ComfortNet system the outdoor control, the indoor unit and the thermostat run as one configured machine, and the outdoor control holds a data set describing the exact model and match. d0 says that data was never loaded. d1 says what is loaded is invalid. d2 says the data describes a system whose parts do not match — classically an outdoor unit demanding more airflow than the indoor unit can deliver. d3 says the data does not match the hardware it is running on, and d4 says the memory card offered to fix all this was itself rejected. These codes cluster around human moments: a control board replaced in a hurry, a system installed and never commissioned, an indoor or outdoor unit swapped for a near-match that is not a match. Their repair is correspondingly unglamorous and exact, straight from Goodman's tables: verify the system type, take the memory card for the SPECIFIC model — not the same tonnage, not the same family, the specific model — insert it before power is turned on, let the data load, and the code clears when correct data lands. The discipline matters because the d-family is the one place where guessing is directly harmful: loading plausible-but-wrong shared data does not just fail to clear the code, it teaches the system a false description of itself, and every staging and airflow decision it makes afterwards is made about a machine that does not exist. When a d-code appears on a system nobody has touched in years, that too is information — controls that lose or corrupt their data are controls beginning to fail, and EE (board misoperation) is usually not far behind in the story.
Related guides
Facts on this page were checked against manufacturer documentation: resource.ecmdi.com · www.manualshelf.com · manualmachine.com · www.manualshelf.com