FieldBench
Bosch codes

Bosch

E9

Lockout

EEPROM fault

Outdoor control EEPROM / memory chip.

Walk E9 in Diagnose

Sign in for the next measurement

First check

1 Write the live code and watch one cycle

On Bosch BOVA 2.0 read BOVA outdoor inverter PCB + BVA indoor board before you pull power. Write E9 exactly. Watch one full sequence and note which step dies. L1–L2 in range. If E9 remains, the outdoor board — not a Daikin indoor IFC.

Expect: Stat call: 24 V at the AHU (Y cool, B/O reversing, G fan, W strips). The AHU then talks to the outdoor on the comm cable. No Y at the outdoor like a contactor unit.

The rest of the walkthrough is Diagnose.

On the plates

  • L1–L2 in range. If E9 remains, the outdoor board — not a Daikin indoor IFC.
  • Do not ‘reprogram’ this like ComfortBridge shared data.

Plates that use E9

Same number, other makers

E9 on Bosch is not the same code on these plates.