LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2022 >> 3 Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 33 (Basic System) >> Heater Core Inspection (Us)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Heater Core Inspection (Us)

WARNING: This page is about a different car, the 2021 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
  1. Disconnect the negative battery terminal and wait for 1 min or more. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .)
  2. Discharge the refrigerant. (See REFRIGERANT RECOVERY .) (See REFRIGERANT CHARGING (US) .)
  3. Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT [(VIN 7 & VIN L) (US)] .) (See ENGINE COOLANT REPLACEMENT [(VIN M) (US)] .) (See ENGINE COOLANT REPLACEMENT [(VIN Y) (US)] .)
  4. Remove the following parts:
    1. Plug hole plate (See PLUG HOLE PLATE REMOVAL/INSTALLATION [(VIN 7 & VIN L) (US)] .) (See PLUG HOLE PLATE REMOVAL/INSTALLATION [(VIN M) (US)] .) (See PLUG HOLE PLATE REMOVAL/INSTALLATION [(VIN Y) (US)] .)
    2. A-pillar trim (See A-PILLAR TRIM REMOVAL/INSTALLATION .)
    3. Front scuff plate (See FRONT SCUFF PLATE REMOVAL/INSTALLATION .)
    4. Front side trim (See FRONT SIDE TRIM REMOVAL/INSTALLATION .)
    5. Passenger-side decoration panel (See DECORATION PANEL REMOVAL/INSTALLATION .)
    6. Glove compartment (without passenger-side knee air bag module) (See GLOVE COMPARTMENT REMOVAL/INSTALLATION .)
    7. Dashboard under cover (See DASHBOARD UNDER COVER REMOVAL/INSTALLATION .)
    8. Passenger-side lower panel (See LOWER PANEL REMOVAL/INSTALLATION (US) .)
    9. Passenger-side knee air bag module (with passenger-side knee air bag module) (See KNEE AIR BAG MODULE REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
    10. Driver-side decoration panel (See DECORATION PANEL REMOVAL/INSTALLATION .)
    11. Hood release lever (See HOOD RELEASE LEVER AND RELEASE CABLE REMOVAL/INSTALLATION (US) .)
    12. Selector lever knob (ATX) (See SELECTOR LEVER COMPONENT REMOVAL/INSTALLATION .)
    13. Shift lever knob (MTX) (See SHIFT LEVER REMOVAL/INSTALLATION [C66M-R] .)
    14. Shift panel (See SHIFT PANEL REMOVAL/INSTALLATION .)
    15. Front console box (See FRONT CONSOLE BOX REMOVAL/INSTALLATION .)
    16. Cup holder (See CUP HOLDER REMOVAL/INSTALLATION .)
    17. Side wall (See SIDE WALL REMOVAL/INSTALLATION .)
    18. Rear console (See REAR CONSOLE REMOVAL/INSTALLATION (US) .)
    19. Driver-side lower panel (See LOWER PANEL REMOVAL/INSTALLATION (US) .)
    20. Driver-side knee air bag module (See KNEE AIR BAG MODULE REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
    21. Center lower panel (See LOWER PANEL REMOVAL/INSTALLATION (US) .)
    22. Upper column cover (See COLUMN COVER REMOVAL/INSTALLATION .)
    23. Lower column cover (See COLUMN COVER REMOVAL/INSTALLATION .)
    24. Driver-side air bag module (See DRIVER-SIDE AIR BAG MODULE REMOVAL [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .) (See DRIVER-SIDE AIR BAG MODULE INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
    25. Steering wheel (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION (US) .)
    26. Clock spring (See CLOCK SPRING REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
    27. Light switch (See LIGHT SWITCH REMOVAL/INSTALLATION (US) .)
    28. Wiper and washer switch (See WIPER AND WASHER SWITCH REMOVAL/INSTALLATION (US) .)
    29. Joint cover (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION (US) .)
    30. Steering shaft (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION (US) .)
    31. Instrument cluster (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
    32. Center speaker grill (See SPEAKER GRILLE REMOVAL/INSTALLATION .)
    33. Center display component (See CENTER DISPLAY REMOVAL/INSTALLATION .)
    34. Connectivity master unit (CMU) (See CONNECTIVITY MASTER UNIT (CMU) REMOVAL/INSTALLATION .)
    35. Audio panel (See AUDIO PANEL REMOVAL/INSTALLATION (US) .)
    36. Climate control unit (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (US)] .) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (US)] .)
    37. Dashboard side cover (See DASHBOARD SIDE COVER REMOVAL/INSTALLATION .)
    38. Rear heat duct No. 1 (See REAR HEAT DUCT REMOVAL/INSTALLATION (US) .)
    39. Windshield wiper arm and blade (See WINDSHIELD WIPER ARM AND BLADE REMOVAL/INSTALLATION .)
    40. Cowl grille (See COWL GRILLE REMOVAL/INSTALLATION .)
    41. Dashboard (See DASHBOARD REMOVAL (US) .) (See DASHBOARD INSTALLATION (US) .)
    42. Blower unit (See BLOWER UNIT REMOVAL/INSTALLATION (US) .)
    43. Front heat duct No. 1 (See FRONT HEAT DUCT REMOVAL/INSTALLATION (US) .)
    44. Foot support (See FOOT SUPPORT REMOVAL/INSTALLATION .)
  5. Remove the A/C unit. (See A/C UNIT REMOVAL/INSTALLATION (US) .)
  6. Remove the heater core. (See A/C UNIT DISASSEMBLY/ASSEMBLY (US) .)
  7. Inspect the heater core for damage, cracks, and water leakage.
  8. Visually inspect the fins for bending.
    • If there is any bending, use the end of a flathead screwdriver to straighten the fins.
  9. Visually inspect the heater hose for deformation.
scientia non olet · About LEMON Manuals