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BMW
🟡 Medium
BMW
P0128
BMW P0128 Coolant Thermostat Plausibility
The P0128 fault on your BMW indicates a BMW P0128 Coolant Thermostat Plausibility. Your BMW has registered an anomaly during a diagnostic self-test, indicating the system is struggling to reach its target operating range.
Brand
BMW
Fault Code
P0128
Severity
🟡 Medium
Models
1/2/3/4/5/7 Series, X1-X7, Z4
🛠️ Diagnostic Overview
Difficulty Level
🛠️🛠️
Medium (Moderate)
Estimated Time
⏱️ 1-2 Hours
🧰 Required Tools
- ✓ Digital Multimeter
- ✓ Socket Wrench & Hand Tools
⚠️ Possible Causes
- • Thermostat mechanically stuck open
- • Heating element inside map-controlled thermostat burned out
- • Faulty coolant temperature sensor
🔧 Recommended Fixes
- → Replace the thermostat (Wahler/BorgWarner recommended) and water pump
- → Bleed the cooling system and refill with BMW blue/green coolant
🚗 Commonly Affected Vehicles
🏭 BMW – Other Common Fault Codes
P0597
BMW P0597 Thermostat Heater Control Circuit Open
🟡 Medium
P0102
BMW P0102 Mass Air Flow (MAF) Circuit Low Input
🔴 High
P0456
BMW P0456 EVAP System Very Small Leak Detected
🟢 Low
P1014
BMW P1014 Valvetronic Eccentric Shaft Sensor Reference
🚨 Critical
P0420
BMW P0420 Catalyst System Efficiency Below Threshold
🟡 Medium
P112F
BMW P112F Manifold Absolute Pressure to Throttle Angle
🔴 High
P0300
BMW P0300 Random/Multiple Cylinder Misfire
🚨 Critical
P0174
BMW P0174 System Too Lean Bank 2 (Vacuum Leak)
🔴 High
P0171
BMW P0171 System Too Lean Bank 1 (Vacuum Leak)
🔴 High
5E20
BMW 5E20 ABS DSC Hydraulic Pressure Sensor Fault
🚨 Critical
4X4
BMW xDrive Transfer Case Actuator Fault (VTG)
🔴 High
CDA1
BMW CDA1 Steering Angle Sensor Message Error
🟢 Low
2E9F
BMW 2E9F Oil Condition Sensor Communication Error
🟡 Medium
2C31
BMW 2C31 Lambda Control Sensor Fault
🟡 Medium
2FCA
BMW 2FCA High Pressure Fuel Pump (HPFP) Failure
🔴 High
2A87
BMW 2A87 VANOS Exhaust Mechanism Jammed
🔴 High
2A82
BMW 2A82 VANOS Intake Mechanism Jammed
🔴 High
30FF
BMW 30FF Turbocharger Boost Under-Target
🚨 Critical
2A17
BMW 2A17 DMTL Leak Diagnosis Pump Fault
🔴 High
29F1
Valvetronic Eccentric Shaft Sensor Plausibility
🔴 High
280D
Fuel Trim System Too Lean – VANOS Related
🔴 High
29E0
Throttle Valve Activation / Adaptation Failure
🔴 High
4530
DSC: Steering Angle Sensor Plausibility
🟡 Medium
A060
Gearbox: Mechatronic Adaptation Limit Reached
🔴 High
002E
N47/N57 Diesel: Swirl Flap Actuator Fault
🔴 High
27D1
High Pressure Fuel Pump: Pressure Buildup Too Slow
🟡 Medium
CC-ID
N47 Timing Chain / Coolant Loss Warning
🔴 High
2A1A
BMW Tank Venting System Function
🟡 Medium
2A98
BMW Crankshaft - Inlet Camshaft Correlation
🔴 High
2A99
BMW Crankshaft - Exhaust Camshaft Correlation
🔴 High
2C9C
BMW Oxygen Sensor Heater 1 Before Catalyst
🟡 Medium
2E81
BMW Electric Coolant Pump Speed Deviation
🚨 Critical
2E82
BMW Electric Coolant Pump Cutoff
🚨 Critical
2F9E
BMW Thermal Oil Level Sensor Fault
🟢 Low
30BA
BMW DME Internal Failure: Injector Bank 1
🚨 Critical
30BB
BMW DME Internal Failure: Injector Bank 2
🚨 Critical
2C6C
BMW Oxygen Sensor 2 After Catalyst System Check
🟡 Medium
2EF7
BMW Map Thermostat Activation Fault
🟡 Medium
2F0D
BMW Radiator Blind Activation Fault
🟡 Medium
2A80
BMW Intake VANOS Variable Camshaft Timing
🔴 High
2A85
BMW Exhaust VANOS Variable Camshaft Timing
🔴 High
2B62
BMW Camshaft Sensor Intake Plausibility
🟡 Medium
2C3D
BMW Oxygen Sensor Before Cat: Line Fault
🟡 Medium
2D06
BMW Air Mass System: Plausibility
🟢 Low
2DED
BMW Power Management: Standby Current Violation
🟢 Low
2E18
BMW Ignition Coil Cylinder 1 Activation
🟡 Medium
2E19
BMW Ignition Coil Cylinder 2 Activation
🟡 Medium
2EFE
BMW Misfire Detected - Multiple Cylinders
🟡 Medium
2F08
BMW Intake Air Temperature Sensor Signal
🟢 Low
3100
BMW Boost Pressure Control: Deactivation
🔴 High
4801
BMW DSC: Pressure Sensor Failure
🟡 Medium
5DE0
BMW Brake Pad Wear Sensor: Line Fault
🟢 Low
9C69
BMW Stratification Potentiometer Fault
🟡 Medium
A0B3
BMW CAS: Starter Activation Fault
🟡 Medium
A0B4
BMW Engine Start: Logic Failure
🔴 High
CC-ID 164
BMW Windshield Washer Fluid Low
🟢 Low
CC-ID 24
BMW Dynamic Stability Control (DSC) Disabled
🟢 Low
102001
BMW Air Mass: Plausibility Too High
🔴 High
120308
BMW Charging Pressure: Too Low
🔴 High
130E20
BMW Intake Camshaft: Angle Offset cold start
🔴 High
140001
BMW Misfire: Multiple Cylinders
🟡 Medium
150C11
BMW Ignition Coil: Dwell Time too low
🟢 Low
190302
BMW Fuel Tank Ventilation: System check
🟡 Medium
1B5302
BMW Supply Voltage: Battery too low
🟢 Low
20A701
BMW Coolant Pump: Speed zero detected
🚨 Critical
420651
BMW Transmission Control: Emergency Mode
🚨 Critical
480A2C
BMW Wheel Speed Sensor: Front Left
🟡 Medium
800F92
BMW Welcome Light: Failure
🟢 Low
E11451
BMW Steering Angle: Sensor Not Initialized
🟢 Low
P1637
BMW CAN Bus Link: Throttle Control
🟡 Medium
P2187
BMW System Too Lean at Idle Bank 1
🟡 Medium
P2189
BMW System Too Lean at Idle Bank 2
🟡 Medium
P0401
BMW EGR: Insufficient Flow
🟡 Medium
4B10
BMW Rough Idle: Injection Correction
🔴 High
4C5E
BMW Particulate Filter: System Overloaded
🔴 High
5EBA
BMW Steering Angle Sensor: Internal Fault
🟡 Medium
D355
BMW CAN Bus: Torque Demand Fault
🟢 Low
D014
BMW Servotronic: Failure
🟢 Low
801C20
BMW ZGM: Central Gateway Comm Failure
🟢 Low
9313
BMW Airbag: Seat Occupancy Sensor
🟡 Medium
C90B
BMW PDC: Sensor failure
🟢 Low
A3B4
BMW Radio: Antenna Signal Weak
🟢 Low
P103A
BMW Variable Valve Lift: Position Unplausible
🔴 High
P1062
BMW Valvetronic: Limp Mode Mode 1
🔴 High
29E1
BMW Mixture Control 2: Too Lean
🟡 Medium
2EE0
BMW Coolant Temp Sensor: Plausibility
🟡 Medium
2F4F
BMW Speed Signal: Plausibility
🟢 Low
2F0C
BMW Intake Air Temperature: Signal High
🟢 Low
30CF
BMW Boost pressure control: high pressure
🔴 High
30D0
BMW Boost pressure control: high pressure 2
🔴 High
2A2B
BMW Mixture Control: Fuel system too lean
🟡 Medium
2A2C
BMW Mixture Control 2: Fuel system too lean
🟡 Medium
2C9D
BMW Oxygen Sensor Heater 2 Before Cat
🟡 Medium
2CA0
BMW Oxygen Sensor heater 1 After Cat
🟡 Medium
2CA1
BMW Oxygen Sensor heater 2 After Cat
🟡 Medium
2D52
BMW Super knocking: Cylinder 1
🟢 Low
2D54
BMW Super knocking: Cylinder 2
🟢 Low
2D56
BMW Super knocking: Cylinder 3
🟢 Low
2D58
BMW Super knocking: Cylinder 4
🟢 Low
2DE4
BMW Fuel level sensor: Left side range
🟢 Low
2DE5
BMW Fuel level sensor: Right side range
🟢 Low
2FBC
BMW Fuel Pressure control: pressure too low
🔴 High
2FBD
BMW Fuel Pressure control: pressure too high
🔴 High
2FCE
BMW Engine oil temp: Sensor range
🟢 Low
2FD3
BMW Brake vacuum sensor: Signal fault
🟢 Low
2A18
BMW DMTL heating: Activation
🟡 Medium
2A19
BMW Tank venting valve: Output stage
🟡 Medium
29CC
BMW Misfire: Multiple cylinders
🟡 Medium
2A2E
BMW Mixture Control: Too rich
🟡 Medium
2A2F
BMW Mixture Control 2: Too rich
🟡 Medium