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Error code reference

Fisher & Paykel Dishwasher Error Code F9

Power Supply / Controller Fault

Fisher & Paykel codesFisher & Paykel dishwasher codes

Power Supply / Controller Fault – the product will disable power supply, log the fault, lock out the user and report via a fault code.

First step from the service manual

Disconnect then reconnect the power to the product at the wall socket. Wait 20 seconds after power up; if F9 appears in this time, check harness connections (especially POWER and DISPENSER), measure dropper resistor resistance, and measure detergent diverter resistance.

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

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What F9 means on a Fisher & Paykel dishwasher

The F9 error code on a Fisher & Paykel dishwasher indicates a Power Supply or Controller Fault. When this fault is detected, the dishwasher's control system responds by disabling the power supply, logging the event internally, locking out user input, and displaying the F9 code. This is a protective response designed to prevent damage to the electronics or connected components when an abnormal electrical condition is detected in the power or control circuit.

The fault is most closely associated with two areas of the wiring harness: the POWER connection and the DISPENSER connection. A failure in either of these harness paths can trigger the controller to flag an F9. Beyond harness integrity, the dropper resistor and the detergent diverter are both key components in the diagnostic chain. The dropper resistor is a current-limiting component in the power supply circuit, and an out-of-specification resistance reading here points to a breakdown in that stage. The detergent diverter, which controls the routing of detergent during the wash cycle, also has a measurable resistance value that must fall within an acceptable range.

Diagnosis begins with a power cycle: disconnect the unit from the wall socket, wait at least 20 seconds after reconnecting power, and observe whether F9 reappears within that window. If it does, the fault is persistent rather than transient. At that point, inspection and measurement are required: check harness connectors at the POWER and DISPENSER points for corrosion, looseness, or damaged pins, then use a multimeter to measure resistance across the dropper resistor and detergent diverter to confirm whether either component is outside acceptable parameters.

Source: manufacturer service documentation.

Common causes of F9

  1. 01

    Loose or damaged harness connection

    Wiring / connection

    A poor connection at the POWER or DISPENSER harness connector is a leading cause of F9. Inspect both connectors for bent pins, corrosion, or connectors that are not fully seated.

  2. 02

    Faulty dropper resistor

    Part replacement

    The dropper resistor in the power supply circuit can fail or drift out of specification, causing the controller to detect an abnormal supply condition. Measure its resistance with a multimeter to determine if it is within the correct range.

  3. 03

    Failed or out-of-spec detergent diverter

    Part replacement

    The detergent diverter has a resistance value that the controller monitors. If the diverter winding is open, shorted, or reading outside its expected resistance range, it can contribute to or trigger the F9 fault.

  4. 04

    Transient power supply disturbance

    Wiring / connection

    A brief voltage fluctuation or power interruption from the mains supply can cause the controller to log an F9 without any component actually failing. A full power cycle resolves this in many cases.

  5. 05

    Controller board fault

    Part replacement

    If harness connections, the dropper resistor, and the detergent diverter all test correctly, the controller board itself may have an internal fault causing it to incorrectly detect or report a power supply problem.

See the test procedure for each cause

Frequently asked questions about F9

What does F9 mean on a Fisher & Paykel dishwasher?
F9 indicates a Power Supply or Controller Fault. When this code appears, the dishwasher disables its power supply, locks out the controls, and logs the fault internally. The code points to an issue in the power circuit or a connected component such as the dropper resistor or detergent diverter. Diagnosis involves checking harness connections and measuring component resistance values.
Will resetting the dishwasher clear the F9 code?
A power cycle is always the recommended first step: unplug the dishwasher from the wall, wait 20 seconds after restoring power, and observe whether F9 returns. If the fault was caused by a temporary power disturbance, the reset may clear it permanently. If F9 reappears within 20 seconds of power-up, the underlying cause is still present and further diagnosis of the harness and components is required.
Is it safe to use my dishwasher when F9 is displayed?
No. When F9 is active, the dishwasher has already disabled its power supply and locked out user controls as a protective measure. Attempting to bypass the lockout or continue operation without resolving the fault is not recommended. The dishwasher should remain out of service until the fault is diagnosed and corrected.
How do I fix an F9 error on a Fisher & Paykel dishwasher?
Start with a power cycle by unplugging the unit at the wall and waiting before reconnecting. If F9 returns promptly, inspect the POWER and DISPENSER harness connectors for damage or poor seating. Use a multimeter to measure the resistance of the dropper resistor and the detergent diverter, comparing readings against specification. If a component is out of range or a connector is damaged, that component or harness section will need to be repaired or replaced.
How much does it cost to repair an F9 fault on a Fisher & Paykel dishwasher?
Repair cost depends on the root cause. If the fix is a reseated harness connector, out-of-pocket costs may be minimal beyond a service call fee, which typically ranges from around $80 to $150. Replacing a dropper resistor or detergent diverter generally adds $50 to $200 in parts and labor. A controller board replacement represents the higher end of the cost range, often $200 to $500 or more depending on parts availability and local labor rates.

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