E18
General Motors Current Sensing / Calibration Error

GM charger displays E18; charging may start but is limited to a very low current or stops unexpectedly.

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Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

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Possible Causes

Faulty output current sensor, Loose sensor connector on main board, Corrupted calibration data in firmware, Damaged shunt resistor in power module

How to Fix / Troubleshooting

Steps:

  • Power reset: Turn OFF the breaker for 5 minutes, then turn it back ON to force a fresh self‑test.
  • Firmware update: Use the GM app to check for and install any available firmware updates that may recalibrate sensors.
  • Observe behavior: If the charger consistently reports incorrect current in the app or on the display, note the values for the technician.

Because current sensing is critical for safety, do not attempt to bypass or modify sensors. Persistent E18 requires professional service or replacement of the GM power module or main board.

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Repair Difficulty

Professional Required 5/5

Required Part

GM Output Current Sensor / Shunt Assembly
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