EN

Severity: Moderate

Speed Queen Washing Machine Error Er CO – Causes & Fix

Speed Queen washer Er CO: the front control and the drive or output board stopped exchanging data.

At a glance

Severity: 3/5 – Moderate3/5

Severity: Moderate

Meaning
Board Communication Error – Controls Out of Sync
Typical repair cost
$0–$750
DIY difficulty
Hard

Speed Queen washers with electronic controls split the work between two boards: the front end control behind the knobs and display, and a power board that switches the motor, valves and pump – the drive board on front-loaders, the output board on top-loaders. Er CO (shown as Er alternating with CO or Co) means those two boards have lost communication. Alliance Laundry's error list for home and light-commercial controls says to power down and try again first, then check the harness between the boards, and notes that a loose pin or wire is very often the culprit on front-loaders; on top-loaders it calls out burnt pins and breaks in the main harness. A board replacement is the last step, not the first.

How it looks on the display

Speed Queen Washing Machine display showing error Er CO

Model families & display variants

Model familyShowsNote
Speed Queen front-load washers (e.g. FF7)Er / CoDrive board communication error between the front end control and the drive board.
Speed Queen top-load washers with electronic controls (e.g. TC5)Er / COCommunication error between the front end control and the output board over the main harness.
Notation seen in manuals and videosE CO / E:COSame code written with a different separator.
Mechanical-timer models such as TR3noneNo electronic boards of this kind, so no Er CO.

Safety first · Consult a professional

Unplug the washer before removing the console or any panel. The drive and output boards carry line voltage and, on front-loaders, stored energy in the motor drive circuit.

  • Unplug the appliance or switch off the breaker before opening any panel. Mains voltage can kill.

Symptoms

  • Er and CO alternate on the display and the washer won't start or stops mid-cycle
  • Error clears after unplugging, then returns days or loads later
  • Display dim or flickering before the error appears
  • Other board-level codes such as nr (not ready) show on some occasions
  • Problem started after the washer was moved, serviced or flooded

Possible causes

Ranked by how often each cause is behind this code (editorial estimate).

  1. Loose, backed-out or corroded pin in the harness connector between the two boards 34%
  2. Break, pinch or chafe in the main harness (often where it passes into the console or near the motor) 20%
  3. Momentary power disturbance – brownout, surge or a loose outlet 16%
  4. Burnt or heat-damaged connector pins 12%
  5. Failed drive board or output board 10%
  6. Failed front end control 8%

Fix it step by step

Diagnostic flow: Er CO1Power down and restart2Check the outlet and supply3Find the harness between the boards4Reseat every connector5Trace the harness for damage6Decide on boards

  1. Power down and restart

    Speed Queen's first instruction for Er CO is to remove power, restore it and try again. Unplug the washer for at least a minute. A single event after a storm or power flicker often doesn't return.

  2. Check the outlet and supply

    Make sure the plug fits tightly and the outlet doesn't feel warm or loose. Don't run the washer on an extension cord; voltage dips at the outlet can disrupt communication between the boards.

    Tools: Multimeter

  3. Find the harness between the boards

    With the washer unplugged, open the console or top panel following your model's service instructions and locate the harness running from the front end control down to the drive or output board.

    Tools: Screwdriver, Flashlight

  4. Reseat every connector

    Unplug and firmly reseat each connector on both boards. Look into the housings for pins pushed back, green corrosion or brown heat marks. On front-loaders Alliance specifically says many cases come down to a loose pin or wire.

    Tools: Flashlight, Pliers

  5. Trace the harness for damage

    Follow the harness along the cabinet, checking clips and edges where it could be pinched or rubbed through. Continuity-test suspect wires end to end with a multimeter using the wiring diagram.

    Tools: Multimeter, Flashlight

  6. Decide on boards

    If the connections are sound and Er CO keeps returning, one of the two boards is failing. A technician can tell which from the diagnostic tests; boards are expensive, so avoid guessing.

How to reset Er CO

  1. Turn the washer off and unplug it – Er CO clears only when power is removed.
  2. Wait at least a minute, then plug back in.
  3. Start a short cycle and watch for the error returning.
  4. If it returns immediately, stop using the washer until the harness and boards are checked.

Where the parts are

Washing machine: drain filter, pump and door lock – Er CO12345678
Washing machine: drain filter, pump and door lock
  1. 1Door lock
  2. 2Water inlet valve
  3. 3Water level sensor
  4. 4Filter
  5. 5Drain pump
  6. 6Motor
  7. 7Heating element
  8. 8Temperature sensor

Repair options & costs

RepairDIY?Estimated cost
Power reset, secure outlet connection Yes $0
Reseat connectors and repair a harness wire Yes $0–$40
Technician harness diagnosis and repair No $150–$300
Drive board or output board replaced by a technician No $400–$750
Front end control replaced by a technician No $350–$650

Rough US estimates; technician call-out fees vary by region. Not a quote.

When to call a technician

Call a Speed Queen dealer or technician if Er CO returns after the connectors have been reseated, if any pins show burn marks, or if the washer was exposed to water inside the cabinet. Speed Queen's home warranty typically includes labor for several years, so check coverage before ordering boards.

Frequently asked questions

Is Er CO on my Speed Queen washer about coins?

Not on home washers. Some code lists written for coin-operated laundromat machines describe a coin fault, but on home and light-commercial electronic controls Alliance defines Er CO as board communication. Use the list for your control type.

Why does Er CO come and go?

Intermittent faults are typical of a loose pin or a harness wire that breaks contact when the cabinet vibrates. That's why reseating connectors is the most useful first repair.

Do I need to replace both boards?

Rarely. Most cases are wiring. If a board is at fault, only one is usually replaced after testing – the drive or output board, or the front end control.

Is the dryer Er CO the same thing?

Speed Queen dryers with electronic controls also have a user control and an output board, and a similar communication code. The washer's troubleshooting is specific to its own harness and boards.

Sources