Speed Queen Washer Error Code Eio 42: Door Lock Input Pin
Eio 42 on a CHM1792C washer-extractor is a hardware failure of the door lock input pin on the input and output board. This is the line that tells the control whether the door is actually locked. Without it the machine will not start or continue a cycle, so hold off on the door until the lock lets go, post a sign, and call us.
High: the lock state cannot be confirmed, and the machine will not run until it is repaired.
- Code
- Eio 42
- Maker
- Speed Queen
- Equipment
- Washers
- Applies to
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
What does Speed Queen error code Eio 42 mean?
Before a washer-extractor spins, the control wants proof that the door is locked, not just a command that it should be. The door lock input line on the input and output board carries that proof back to the control. Eio 42 means the board's input pin for that line failed in hardware. If the board cannot read it, the control has no way to confirm the lock state, so the machine will not start or continue a cycle and the code stays on the display. This is an input failure on the board, not an output one, and so differs from the lock output and pulse codes: the lock itself may work while the control cannot see it. The manual lists a door lock input line on the board that has failed, door lock switch wiring that is open or loose, and a board supply problem that disturbs the input reading. The door must never be bypassed to get around it.
Affected models and control systems
CHM1792C family washer-extractors, QN models, 20 to 100 lb, with the front-end control and its input and output board.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Eio 42 stays on the display and the cycle will not start
- The door lock may click normally
- The machine acts as if the door is unlocked
Possible causes
Listed in Speed Queen's documentation
- A door lock input line on the board that has failed
- Door lock switch wiring that is open or loose
- A board supply problem that disturbs the input reading
Other likely causes — what usually sits behind error code Eio 42 on this control. A technician confirms which one it is before any part is replaced.
- A lock-state switch contact that has worn and no longer closes reliably
- A harness plug at the lock that is only partly seated
Safe checks before calling for service
- Write down the whole code, Eio and its two digits.
- Hold off on the door until the lock lets go.
- Never bypass the door switch.
- Post a sign on the machine and call us to arrange a repair visit.
How a technician diagnoses error code Eio 42
- Read the full code and confirm it returns after a power cycle.
- Check the lock-state switch and its wiring for opens or loose plugs, with power off and locked out.
- Measure the board supply.
- Read the input state with the door locked and unlocked.
- Test the input circuit on the board.
- Replace the switch, wiring or board according to the reading.
- The lock-state circuit is a safety interlock, so it must be tested without being bypassed.
- Reading the input with the door locked means working near live voltage.
- A lock that works but cannot be seen by the control looks like a lock failure until it is measured.
How error code Eio 42 differs from similar codes
Eio 42 is the door lock input pin. The other door lock codes, Eio 30 to 37, concern the lock's outputs and disable circuits.
Technical reference
- Document
- Washer-Extractor Programming CHM1792C_SVG, Part No. F8641001ENR4, Error Codes Table 29 (pp. 100-107)
- Edition
- Part No. F8641001ENR4, January 2020
- Models / control
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
- Section
- Error Codes, Table 29, pp. 100-108 (PDF pages equal printed pages)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related Speed Queen washer error codes
Is the lock broken if I see Eio 42?
Not necessarily. The control may simply be unable to read whether the lock is closed.
Can I bypass the door switch to finish a load?
No. The door switch and lock are never bypassed.
Why will the machine not start?
With no confirmed lock state, the control will not begin or continue a cycle.
Need help with Speed Queen error code Eio 42?
A technician confirms the cause on site and gives you the price in writing before any work starts.