mypros+
Error code reference

Amana Range Error Code LOCK

When displayed and oven is not in clean mode, the oven sensor resistance is too high.

Amana codesAmana range codes

When displayed and oven is not in clean mode, the oven sensor resistance is too high.

First step from the service manual

Check sensor resistance, wire harness and connections.

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

MyPros+ Max

Get the full diagnostic procedure for LOCK.

  • Step-by-step tests with expected resistance, voltage, and continuity values
  • Wiring diagram references and connector pinouts from the OEM service manual
  • Verified part numbers when replacement is required
Get the full procedure

$29/month · Cancel anytime · Or $9.95 3-day pass

What LOCK means on a Amana range

The LOCK error code on an Amana range, when displayed outside of a self-clean cycle, indicates that the oven temperature sensor is producing a resistance reading that is too high. The oven sensor, typically a resistance temperature detector (RTD), changes its resistance value in a predictable way as oven temperature changes. When the control board reads a resistance level beyond the expected upper threshold, it interprets this as a fault condition and displays the LOCK code rather than allowing normal oven operation.

A resistance reading that is too high usually points to an open circuit or a degraded sensor element. In a properly functioning RTD sensor, resistance increases with temperature in a controlled, linear fashion. If the sensor's internal element has broken down, corroded, or partially failed, resistance can spike well outside the normal operating range. Similarly, damaged wiring between the sensor and the control board can introduce unwanted resistance into the circuit, mimicking a faulty sensor reading even when the sensor itself is intact.

The first diagnostic step is to check the sensor's resistance with a multimeter, then inspect the wire harness and all connections between the sensor and the control board. A loose connector, corroded terminal, or pinched wire can all cause abnormally high resistance readings. If the wiring and connections check out, the sensor itself should be tested and replaced if its resistance reading falls outside the expected range for the current oven temperature.

Source: manufacturer service documentation.

Common causes of LOCK

  1. 01

    Failed oven temperature sensor

    Part replacement

    The RTD sensor element inside the oven cavity can break down or fail open, producing a resistance reading that is too high for the control board to accept. Testing the sensor with a multimeter will reveal whether its resistance is outside the expected range for room temperature.

  2. 02

    Loose or disconnected wiring connector

    Wiring / connection

    A connector that has worked loose at either the sensor end or the control board end can add resistance to the circuit, triggering this fault. Visually inspect and reseat all connectors in the sensor circuit.

  3. 03

    Damaged or corroded wire harness

    Part replacement

    Heat, moisture, or physical damage to the wiring between the sensor and the control board can cause increased resistance or an intermittent open circuit. Look for burned insulation, pinched wires, or corroded terminals along the harness routing.

  4. 04

    Corroded sensor terminals

    Wiring / connection

    Corrosion at the sensor's plug terminals can create high resistance in the circuit without fully breaking the connection. Cleaning or replacing the connector may resolve the fault if the sensor and harness otherwise test correctly.

  5. 05

    Faulty control board

    Part replacement

    If the sensor resistance tests within normal range and all wiring connections are secure and undamaged, the control board may be misreading the sensor signal due to a failed input circuit. This is the least common cause and should be investigated after ruling out sensor and wiring issues.

See the test procedure for each cause

Frequently asked questions about LOCK

What does LOCK mean on a Amana range?
When the LOCK code appears on an Amana range and the oven is not running a self-clean cycle, it means the control board is detecting an abnormally high resistance reading from the oven temperature sensor. This indicates a problem with the sensor itself, the wiring, or the connectors in that circuit. The oven will not operate normally until the fault is resolved.
Can I fix the LOCK error code on my Amana range myself?
A knowledgeable DIYer can start by unplugging the range, locating the oven temperature sensor, and checking its resistance with a multimeter, along with inspecting the wire harness and connectors for damage or looseness. If the sensor reads outside the expected range or wiring damage is found, those components can be replaced. However, if the control board is the source of the fault, board diagnosis and replacement are generally best handled by a qualified technician.
Is it safe to use my Amana range while the LOCK error is displayed?
You should not attempt to use the oven while this error code is active. The control board cannot accurately monitor oven temperature with a faulty sensor circuit, which means it cannot regulate heat properly or prevent overheating. Continuing to operate the oven under these conditions could create a safety hazard.
Will resetting my Amana range clear the LOCK error code?
Disconnecting the range from power for a few minutes may temporarily clear the code, but if the underlying fault in the sensor or wiring is still present, the code will return when the oven is used again. A reset is useful for confirming whether the fault is intermittent, but it is not a repair. The root cause must be diagnosed and corrected.
How much does it cost to repair the LOCK error on an Amana range?
Repair costs vary depending on what component has failed. Oven temperature sensors are generally affordable parts, typically in the range of $20 to $60 for the part alone, with additional labor costs if a technician performs the repair. If the control board is at fault, costs will be higher, often ranging from $150 to $400 or more depending on the board and labor rates in your area.

Related Amana range codes

All Amana range codes
View all 30 Amana range codes

78,000+ service manuals · 160,000+ error codes · 55+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass