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Error code reference

Kenmore Range Error Code E0 21

Communication break between UIB and Pan Sense Board.

Kenmore codesKenmore range codes

Communication break between UIB and Pan Sense Board.

First step from the service manual

Check UIB to Pan Sense Board harness connections.

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

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What E0 21 means on a Kenmore range

Error code E0 21 on a Kenmore range indicates a communication break between the User Interface Board (UIB) and the Pan Sense Board. The Pan Sense Board is responsible for detecting cookware placement and size on induction or sensor-based cooktop burners, and it communicates this data back to the UIB so the control system can regulate heat output appropriately. When this communication link is interrupted or fails entirely, the control board triggers E0 21 to alert the technician that the two boards are no longer exchanging data correctly.

The most common root cause of this fault is a problem with the wiring harness that runs between the UIB and the Pan Sense Board. Connectors can become loose due to vibration over time, and the wiring itself can suffer from pinched, burned, or broken conductors, especially near areas exposed to cooking heat. Corrosion at connector terminals is another frequent culprit, particularly in environments with high humidity or grease exposure, as corroded contacts increase resistance and disrupt the low-voltage communication signal.

If the harness and connectors check out as intact and properly seated, the fault likely lies in one of the two boards themselves. Either the UIB or the Pan Sense Board may have failed internally, preventing signal transmission or reception. In some cases, a software glitch or transient voltage spike can mimic a communication failure, which is why a hard reset is often attempted first before condemning hardware components.

Source: manufacturer service documentation.

Common causes of E0 21

  1. 01

    Loose or disconnected harness connector

    Wiring / connection

    The wiring harness connecting the UIB to the Pan Sense Board may have come loose at one or both ends. Inspect each connector for a firm, fully seated connection and listen for an audible click when reseating.

  2. 02

    Damaged or pinched wiring harness

    Part replacement

    The harness between the two boards can suffer physical damage from heat exposure, sharp edges, or improper reassembly after prior service. Visually inspect the full length of the harness for burns, cuts, or pinch points.

  3. 03

    Corroded or dirty connector terminals

    Wiring / connection

    Grease and moisture can corrode the terminal pins inside the harness connectors, raising contact resistance enough to break the communication signal. Check the terminals for discoloration, oxidation, or debris and clean with electrical contact cleaner if needed.

  4. 04

    Failed Pan Sense Board

    Part replacement

    If the harness and connectors are confirmed good, the Pan Sense Board itself may have failed internally. A failed board will not transmit data regardless of connection quality and will need to be replaced.

  5. 05

    Failed User Interface Board (UIB)

    Part replacement

    The UIB may have lost its ability to receive or process signals from the Pan Sense Board due to internal component failure. This is typically diagnosed after ruling out wiring issues and a faulty Pan Sense Board.

See the test procedure for each cause

Frequently asked questions about E0 21

What does E0 21 mean on a Kenmore range?
E0 21 indicates a communication break between the User Interface Board and the Pan Sense Board. These two boards share data so the range can detect cookware and control cooktop output. When that communication link fails, the range displays this code to signal a wiring or board-level fault.
Will resetting the range clear the E0 21 error code?
A hard reset by cutting power at the breaker for several minutes can clear the code if the fault was caused by a transient voltage spike or a temporary software glitch. However, if the underlying cause is a loose connector, damaged harness, or failed board, the code will return once power is restored and the system attempts communication again.
How do I fix E0 21 on my Kenmore range?
Start by checking the wiring harness that runs between the UIB and the Pan Sense Board, as loose or corroded connectors are the most common cause. Reseat all connectors firmly and inspect the harness for visible damage. If the connections are secure and the error persists, one of the two boards likely needs to be tested and possibly replaced.
Is it safe to use my Kenmore range while E0 21 is displayed?
Operating the range while this error is active is not recommended. The Pan Sense Board provides data the control system uses to regulate the cooktop, and using the appliance without that communication functioning correctly could result in unpredictable behavior. It is best to resolve the fault before resuming normal use.
How much does it cost to repair a Kenmore range showing E0 21?
If the issue is simply a loose or corroded connector, repair costs may be minimal, covering only a service call fee in the range of $75 to $150. If a wiring harness needs replacement, parts and labor could bring the total to $150 to $300. Replacing a failed UIB or Pan Sense Board typically costs between $200 and $450 depending on parts availability and local labor rates.

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