What this error means
Electrical communication fault — the control board has lost contact with a sub-module or component.
The E90 error on an AEG washing machine indicates a communication failure between the main control board and one or more internal electronic modules or sensors. AEG washing machines use a serial communication bus to exchange data between the main board, the motor control module, the user interface panel, and various sensors. E90 appears when this communication is interrupted or fails entirely. The most common causes are a wiring harness connector that has worked loose, corrosion on connector pins, a power surge that has disrupted the communication bus, or a failed control board or sub-module.
What you'll need first
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Step-by-step
Symptoms to look for
- Machine will not start any programme — E90 appears immediately on selection
- Controls respond only partially or behave erratically — buttons register but no programme begins
- Machine starts correctly then stops unpredictably mid-cycle with E90
- Display shows partial or scrambled information alongside E90
Diagnostic steps
Unplug the machine and hold the power button for 15 seconds to fully drain capacitor charge from the control board. Leave unplugged for a minimum of 10 minutes. Plug back in and try a cold Rinse and Spin immediately.
With the machine completely unplugged, remove the top panel by undoing the two or three screws at the rear and sliding the panel backward. On most AEG models the main control board is mounted beneath the top panel at the rear of the machine. Photograph all wiring harness connections on the board in detail before touching anything.
Work methodically across every wiring connector on the main board. Each connector should be pressed firmly and evenly into its socket until it clicks or seats flush. Pull each apart and press firmly back in. Pay particular attention to the largest multi-pin connectors which carry the main communication bus signals.
Examine every connector and visible board area for green or white deposits indicating corrosion, for watermarks or rust staining suggesting past moisture ingress, or for visible dampness on connector pins or board tracks. Clean affected connector pins gently with a dry cotton bud.
Trace the wiring from the main board to the control panel and display. Check the harness for any sections pinched in the top panel channel, chafed against a metal edge, or showing wear marks from repeated panel removal. Disconnect and firmly reseat the connector at the board end.
Refit all wiring, replace the top panel, and run two consecutive Rinse and Spin programmes to confirm E90 does not reappear. If it clears for several cycles then returns, the fault is an intermittent connector or harness issue that worsens with vibration.
When to call an engineer
- Visible burn marks, scorch damage, or swollen components on the control board surface
- Corrosion on board connector pins that cannot be cleaned with a dry cotton bud — loom section or connector block needs replacing
- E90 persists on every cycle immediately after a full reset and all connectors have been firmly reseated — board or sub-module has failed
- Ribbon cable or wiring harness to display panel shows visible chafing, cuts, or wear damage
Frequently asked questions
What causes E90 on an AEG washing machine?
Can a power cut cause E90?
Is it safe to keep using the machine after E90?
How do I know if the control board itself needs replacing?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| PCB Control Board | £100 - £200 | 🛒 Amazon UK → |
| PCB Control Board | £50 - £90 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.