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Error code reference

Goodman Heat Pump Error Code d4

Invalid memory card data

Goodman codesGoodman heat pump codes

Invalid memory card data - shared data on memory card has been rejected.

First step from the service manual

Verify system type. Use correct memory card for specific model. Re-populate data if required.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What d4 means on a Goodman heat pump

The d4 error code on a Goodman heat pump indicates that the system's control board has detected invalid or rejected shared data on the installed memory card. Memory cards in these systems store configuration data that defines system type, operating parameters, and model-specific settings. When the control board reads this card during startup or operation and finds that the shared data does not match what is expected for the connected system, it flags the d4 fault to prevent the unit from operating with incorrect configuration values.

This error most commonly arises when a memory card intended for a different model or system type has been installed in the unit. Each Goodman heat pump model requires a memory card programmed with data specific to that configuration. Installing a card from a different system, or one that has become corrupted, will cause the shared data validation check to fail. The control board rejects the card's data rather than risk operating outside of safe or designed parameters.

Diagnosing d4 begins with confirming the system type and cross-referencing the installed memory card to ensure it is the correct card for that specific model. If the card is correct but still triggering the fault, re-populating the card's data may resolve the issue. A card that has experienced data corruption due to voltage irregularities or physical damage may need to be replaced entirely. Technicians should consult the unit's model identification label and verify the card match before proceeding with any reprogramming steps.

Source: manufacturer service documentation.

Common causes of d4

  1. 01

    Wrong memory card installed

    Part replacement

    A memory card from a different model or system type has been installed in the unit. The control board rejects the shared data because it does not match the expected configuration for that specific heat pump model.

  2. 02

    Corrupted memory card data

    Part replacement

    The data stored on the correct memory card has become corrupted, possibly due to a power surge or voltage irregularity. The shared data fails the control board's validation check even though the physical card is the right one for the system.

  3. 03

    Memory card not fully seated

    Wiring / connection

    The memory card may not be properly connected to its slot on the control board, causing incomplete or failed data reads. Reseating the card securely can resolve intermittent or persistent d4 faults in some cases.

  4. 04

    Data needs to be re-populated

    Wiring / connection

    The shared data on the memory card may be incomplete or cleared, requiring a technician to re-populate the correct configuration data for the specific model. This is a programming step rather than a hardware replacement.

  5. 05

    Damaged memory card

    Part replacement

    Physical damage to the memory card, such as bent contacts or cracking, can prevent reliable data communication with the control board. Inspect the card visually and replace it if damage is apparent.

See the test procedure for each cause

Frequently asked questions about d4

What does d4 mean on a Goodman heat_pump?
The d4 code means the control board has detected invalid or rejected shared data on the installed memory card. The system stores model-specific configuration data on this card, and when that data does not match the expected system type, the board flags the fault. The unit will not operate normally until the correct card is installed or the data is corrected.
Can I fix the d4 error myself, or do I need a technician?
Resolving d4 typically requires a technician who can identify the correct memory card for your specific Goodman model and re-populate or replace the card as needed. Homeowners can check that the system has not had recent repairs involving card swaps, but the actual correction requires technical knowledge of the unit's model configuration and programming procedures.
Is it safe to run my Goodman heat pump while it shows a d4 error?
Operating the system while d4 is active is not recommended. The control board rejects the memory card data specifically to prevent the unit from running on incorrect configuration parameters, which could lead to improper operation or component stress. The system should be kept off until the memory card issue is resolved.
Will resetting the heat pump clear the d4 error code?
A simple reset will not clear d4 if the underlying memory card issue has not been corrected. Because the fault is triggered each time the control board reads the invalid shared data, the code will return after any reset as long as the wrong or corrupted card remains installed. The card must be corrected or replaced first.
How much does it cost to fix a d4 error on a Goodman heat pump?
Repair costs vary depending on whether the fix requires only re-populating the card's data or replacing the memory card entirely, plus the technician's labor rate. A service call with data reprogramming typically runs in the range of $75 to $200, while memory card replacement can bring the total to $150 to $400 or more depending on parts availability and local labor rates.

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