Rear HVAC Unit Component Replacement

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2017 Honda Odyssey, 2016 Honda Odyssey, 2015 Honda Odyssey, 2014 Honda Odyssey, and 2013 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

SRS Components are located in this area. Review the SRS component locations (see COMPONENT LOCATION INDEX ) and the precautions and procedures (see PRECAUTIONS AND PROCEDURES ) before doing repairs or service.

NOTE: The rear blower motor (A), the rear power transistor (B), and the rear A/C control unit (C) can be replaced without removing the rear HVAC unit.

Remove the connectors (D): The rear A/C control unit, the rear mode control motor, the rear air mix control motor and rear evaporator temperature sensor (with climate control). Detach the clips (E), then remove the rear A/C wire harness (F). Remove the self-tapping screws, the clamps and rear heater core (G). Remove the self-tapping screw and the rear evaporator temperature sensor (H). Remove the self-tapping screws and the clamp (I).

Fig 1: Rear HVAC Unit Components With Torque Specifications
Courtesy of AMERICAN HONDA MOTOR CO., INC.
If necessary, remove the rear blower motor (see REAR BLOWER MOTOR REPLACEMENT ), the rear A/C control unit (see REAR A/C CONTROL UNIT REPLACEMENT ), the rear power transistor, the rear air mix control motor (J), and the rear mode control motor (K).
Remove the self-tapping screws, and carefully separate the left housing (L) from the right housing (M). Remove the rear evaporator core (N) and plate (O). Remove the tow bolts, the rear evaporator lines (P), and the rear expansion valve (Q).
Reassemble the unit in the reverse order of disassembly, and note these items;
- Replace all O-rings with new ones at each fitting and apply a thin coat of refrigerant oil before installing them. Be sure to use the correct O-rings for HFC-134a (R-134a) to avoid leakage.
- Immediately after using the oil, reinstall the cap on the container, and seal it to avoid moisture absorption.
- Make sure no air is leaking from the left upper housing and the right upper housing fitting and from the upper housings and the lower housing fitting.
- Before reassembly, make sure that the rear air mix control linkage and door move smoothly without binding.
- Before reassembly, make sure that the rear mode control linkage and door move smoothly without binding.
- After reassembly, make sure the rear air mix control motor runs smoothly (see REAR AIR MIX CONTROL MOTOR TEST ).
- After reassembly, make sure the rear mode control motor runs smoothly (see REAR MODE CONTROL MOTOR TEST ).
- Make sure that there is no coolant leakage.