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OEM VERIFIED BENCH
OFFICIAL FAULT CODE4
Bosch
Bosch // OFFICIAL DIAGNOSTIC BENCH

Bosch 4

DishwasherWater Level Pressure Switch & Air Dome
Premium built-in dishwasher with open illuminated stainless steel interior and precision spray arms
Dishwasher

Symptom / Description

FAULT

Bosch 4: Water inlet / filling timeout in Dishwasher; appliance fails to fill to minimum operational level.

TELEMETRY // LIVESIG: FAULT_DETECTED

Root Cause

ROOT CAUSE

Defective Solenoid Valve Coil / Aquastop Pneumatic Valve, open/short circuit in the wiring harness, or faulty connector on the water inlet valve, aquastop & flowmeter.

CIRCUIT // SUBSYSTEMLOGIC: ROOT_ISOLATED

Repair Instructions

UNLOCKED
1Disconnect 230V power. 2. Remove pressure tube from pressure sensor and blow gently to clear debris from tub air trap dome. 3. Check pressure switch contacts or analog frequency output. 4. Ensure airtight tube clamping. 5. Reset: Press and hold Start/Reset for 3 to 5 seconds until display shows 0:01. Turn dial to OFF, wait 15 seconds, turn back ON and run rinse cycle.
AI diagnostic workshop engine analyzing appliance circuit schematics and error telemetry in real time
AI WORKSHOP PROTOCOL ENGINE
Direct extraction from OEM factory manuals & wiring schematics

Field Actions

DISPATCH
Need Help? Call a Certified TechnicianWorldwide Bosch Parts Finder
Electrical & Safety Protocol

Always disconnect appliance from 230V/400V mains before opening panels. Use CAT III multimeter for circuit testing.

CALIBRATED BENCH PROTOCOL // CAT III 600V

Workshop Verification & Safety Checklist

WORKSHOP VERIFICATION PROTOCOLWater Level Pressure Switch & Air DomeDishwasher
2. Multimeter & Electrical Bench Tests (Ω)
MODE: OHMMETER (Ω)AUTO-RANGE
Precision digital multimeter probes measuring electrical resistance in Ohms on an appliance control board
CALIBRATED METROLOGY RESISTANCE BENCH (CAT III)
Nominal Resistance (Ω)
Mechanical: Continuity 0.0Ω–0.2Ω (Empty: 11-12, Full: 11-14). Electronic: 20Ω–45Ω coil resistance.NOMINAL
0 Ω (SHORT)CALIBRATED BAND∞ OL (OPEN)
▲ NOMINAL OPERATING WINDOW
Target Component:Mechanical Pressure Switch Contacts / Inductive Frequency Sensor
Test Pins & Connections
PROBE (+)
PROBE (-)
Across switch spade contacts with harness unplugged; electronic output: 40Hz–50Hz frequency signal
Tolerance & Diagnostic CriteriaMechanical switch contacts must transition cleanly on gentle breath pressure. Coil ~22Ω ±5%.
1. Pre-Intervention Electrical Safety Protocols
  • !Electrical Safety Protocol: Cut 230V mains power before accessing the upper chassis or pressure switch terminals.
  • !Drain appliance tub completely before disconnecting pressure switch sensing hoses.
  • !Never blow high-pressure compressed air into electronic analog pressure sensors: internal diaphragms will rupture!
3. Preliminary Mechanical & Visual Checks
  • Disconnect the silicone pressure tube from the lower air trap and inspect for soap sludge, lint, or water blockage.
  • Inspect the flexible rubber hose along its entire length for pinholes, cracks, or loose clamp fit.
  • Thoroughly flush the lower compression chamber (air dome) with hot water to dissolve detergent buildup.
Perform these diagnostic steps before triggering AI Deep Search or replacing boards.Certified Workshop Routine

Frequently Asked Questions: Bosch 4

FAQ TREE
What does error code 4 mean on a Bosch appliance?

Bosch error code 4 indicates: Bosch 4: Water inlet / filling timeout in Dishwasher; appliance fails to fill to minimum operational level..

What is the root cause of Bosch error code 4?

The primary root cause for Bosch code 4 is: Defective Solenoid Valve Coil / Aquastop Pneumatic Valve, open/short circuit in the wiring harness, or faulty connector on the water inlet valve, aquastop & flowmeter..

How do I fix or resolve Bosch error code 4?

To resolve error code 4: 1. Disconnect 230V power. 2. Remove pressure tube from pressure sensor and blow gently to clear debris from tub air trap dome. 3. Check pressure switch contacts or analog frequency output. 4. Ensure airtight tube clamping. 5. Reset: Press and hold Start/Reset for 3 to 5 seconds until display shows 0:01. Turn dial to OFF, wait 15 seconds, turn back ON and run rinse cycle.

Is it safe to clear Bosch error code 4 by resetting power?

Resetting power (unplugging for 5–10 minutes) clears temporary memory errors. However, if Bosch code 4 persists, the physical component causing Defective Solenoid Valve Coil / Aquastop Pneumatic Valve, open/short circuit in the wiring harness, or faulty connector on the water inlet valve, aquastop & flowmeter. must be inspected or replaced.

How do I test electrical resistance for Bosch code 4 using a multimeter?

Set a digital multimeter to ohms (Ω). Disconnect power and test Mechanical Pressure Switch Contacts / Inductive Frequency Sensor across Across switch spade contacts with harness unplugged; electronic output: 40Hz–50Hz frequency signal. Expected nominal reading is Mechanical: Continuity 0.0Ω–0.2Ω (Empty: 11-12, Full: 11-14). Electronic: 20Ω–45Ω coil resistance.. Tolerance: Mechanical switch contacts must transition cleanly on gentle breath pressure. Coil ~22Ω ±5%..

What safety protocol must be followed before servicing Bosch code 4?

Standard electrical safety protocol: 1. Disconnect 230V mains power before opening panels. 2. Verify zero voltage at test points. 3. Allow hot water or heating elements to cool below 30°C before handling.

Community Verification

COMMUNITY

Did this solution resolve the issue?

SEMANTIC KNOWLEDGE GRAPH // BOSCH

Related Bosch Dishwasher Error Codes

Diagnostic Link Mesh14 OEM Cross-References

Cross-referenced diagnostic codes for technicians inspecting similar component subsystems.

8NTC Temperature Sensor & Thermistor
Fault detected in the NTC temperature sensor circuit
Inspect Protocol
E0Electronic Control Board (PCB) & Bus Communications
No defect or communication problems between electronic modules (appliance stops, no function...
Inspect Protocol
E01Electronic Control Board (PCB) & Bus Communications
Internal power module fault / Program ends / Power supply or pump switching faulty
Inspect Protocol
E02Heating Element, Thermostat & Safety Fuse
Operation without heating / Operation without zeolite drying system
Inspect Protocol
E03Heating Element, Thermostat & Safety Fuse
Temperature control / Overheating / Operation without auxiliary drying system / Operation wi...
Inspect Protocol
E04Heating Element, Thermostat & Safety Fuse
Flow exchanger motor triac faulty (appliance stops, no function possible)
Inspect Protocol
E05Drainage System & Drain Pump
Program interruption (drain)
Inspect Protocol
E06Drive Motor, Inverter & Tachometer Sensor
Door Hall sensor error / Stops in current position, appliance is without function
Inspect Protocol
E07Heating Element, Thermostat & Safety Fuse
Heating error, operation without additional drying system (applies only to appliances with z...
Inspect Protocol
E08Drainage System & Drain Pump
Program continues without heating, or heating works but with insufficient water for circulat...
Inspect Protocol
E09Heating Element, Thermostat & Safety Fuse
Heating circuit or electrical water heating circuit interrupted (resistance, cables, safety ...
Inspect Protocol
E10Heating Element, Thermostat & Safety Fuse
Bosch E10: Water/air heating failure in Dishwasher; heating circuit does not reach set tempe...
Inspect Protocol
E11NTC Temperature Sensor & Thermistor
Bosch E11: NTC temperature sensor signal out of range (open or short circuit) in Dishwasher.
Inspect Protocol
E13Water Inlet Valve, Aquastop & Flowmeter
The appliance detects a water temperature > 75 °C and turns off the heater
Inspect Protocol
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