2017-2018 Pacifica Rear HVAC Module: Fixing No Heat & Programming Guide
This guide covers the common symptoms, replacement costs, and critical programming requirements for the auxiliary heater control module in your 2017-2018 Chrysler Pacifica.
- This module is NOT plug-and-play. It requires a "PROXI Alignment" procedure with a dealer-level scan tool to function after installation.
- Failure typically causes a loss of heat, A/C, or all airflow to the rear seats only; the front climate system will work normally.
- When buying a used module, always try to get the latest part number suffix (e.g., 68226022AG) as it may contain improvements.
- Before replacing the module for a "no heat" issue, first verify the engine coolant level is correct, as low coolant can cause similar symptoms.
Symptoms of a Failing Auxiliary Heater Control Module
When the rear HVAC module begins to fail, the symptoms are usually confined to the rear seating areas. The front climate control will typically continue to work normally. Watch for these specific signs:
- No Heat or A/C in the Rear: The most common symptom is a total loss of heating or cooling for the rear vents. The air that blows out will be at ambient temperature, regardless of the settings.
- Unresponsive Rear Controls: The overhead rear climate control panel may become inoperative, or changes made via the front Uconnect screen for the rear zone will have no effect.
- Incorrect Air Temperature: The rear vents may blow warm or hot air when the A/C is on, or cold air when the heat is on. This indicates the module is not correctly commanding the blend doors.
- No Airflow from Rear Vents: In some cases, the module may fail to activate the rear blower motor, resulting in no air coming from the rear vents at all, even though the fan speed is turned up.
- Diagnostic Trouble Codes (DTCs): A professional scan tool may find Body (B-series) or Communication (U-series) codes stored, such as U0164 (Lost Communication With HVAC Control Module), indicating a fault with the module or its connection to the vehicle's network.
Known Issues, TSBs, and Recalls
As of now, there are no specific recalls or widespread Technical Service Bulletins (TSBs) from Chrysler that target the auxiliary heater control module itself for the 2017-2018 Pacifica. However, it's important to rule out other related issues:
- Other HVAC System Faults: Problems like a failing main A/C compressor, low refrigerant, or a bad heater core can affect the entire system, including the rear. Forum discussions often point to low coolant levels as a potential cause for no heat in the rear, so checking fluid levels is a good first step.
- General Software Updates: Chrysler has issued various software updates for the Powertrain Control Module (PCM) and other systems. While not specific to this part, ensuring your vehicle's software is up-to-date at a dealership can sometimes resolve communication errors between modules.
Warning: A safety recall (NHTSA 18V-332 / FCA U64) was issued for 2017-2018 Pacificas to reprogram the Powertrain Control Module (PCM) for a cruise control issue. This is unrelated to the HVAC module but is an important safety update to have performed.
CRITICAL: Programming and Installation Requirements
Replacing this module is not a simple plug-and-play job. Failure to follow the correct procedure will result in the new module not working.
PROXI Alignment is Required
After the new or used auxiliary heater control module is physically installed, the vehicle requires a PROXI Alignment (also called Proxy Configuration). In simple terms, this procedure is like introducing the new module to the vehicle's main computer, the Body Control Module (BCM). The BCM holds the master configuration for all electronic modules in the van. The PROXI alignment synchronizes this configuration, allowing the new module to be recognized and communicate properly on the vehicle's data network.
Without a PROXI alignment, the new module will not function.
Who Can Perform a PROXI Alignment?
- Chrysler/Dodge/Jeep/Ram Dealers: They have the required wiTECH 2.0 diagnostic tool 🎬 Watch: How to perform a PROXI alignment using the wiTECH tool and a subscription to perform the procedure.
- Qualified Independent Shops: Many professional auto repair shops have high-end aftermarket scan tools (such as Autel or Snap-on) with the capability to perform FCA PROXI alignments.
- Advanced DIY Mechanics: Tools like AlfaOBD or Appcar DiagFCA, paired with a compatible OBD2 interface, can perform this function, but they require significant technical knowledge.
Because of this requirement, a visit to a dealer or a well-equipped shop is necessary for most owners after replacing the part.
Buying a Used HVAC Auxiliary Heater Control Module
A used OEM module is an excellent, cost-effective alternative to a new part, provided you verify a few key details.
- Verify the Part Number: The most critical step is to match the part number. The original part number is 68226022, which has been superseded by newer versions like 68226022AD, 68226022AE, 68226022AF, and 68226022AG. It is always best to purchase the latest version available (highest alphabetical suffix), as it may include internal hardware or software improvements.
- Physical Inspection: When you receive the part, inspect the plastic housing for cracks or signs of heat damage. Carefully check the electrical connector pins to ensure they are straight, clean, and free of any corrosion.
- Factor in Programming Costs: Remember that the price of the used part is not the final cost. You must budget for the PROXI alignment procedure from a dealer or independent shop. Call ahead for quotes.
- Why Used OEM is a Good Choice: A used OEM module is guaranteed to have the correct hardware and base firmware for your vehicle. While some aftermarket modules exist for other vehicles, they can be risky for complex, networked parts like this. A genuine Mopar part, even used, is the most reliable option.
Replacement Cost Breakdown
The cost to fix a faulty auxiliary heater control module can vary significantly based on the path you choose.
| Part / Service | Estimated Cost |
|---|---|
| New OEM Module | $125 - $200 |
| New Aftermarket Module | Not commonly available for this specific model. |
| Used OEM Module | $50 - $125 |
| Shop Labor (Physical Swap & Programming) | $171 - $251 |
Note: Labor costs for 2017-2018 models are estimated between $423-$503 for the total job (parts and labor) at a repair shop. Prices are estimates and may vary by location and supplier.
Frequently Asked Questions (FAQ)
Does the 2017-2018 Pacifica auxiliary heater module need to be programmed?
Yes, absolutely. After installation, the module requires a "PROXI Alignment" procedure to be recognized by the vehicle's computer system. Without this step, it will not work. This must be done with a dealer-level scan tool or a capable professional aftermarket tool.
Where is the auxiliary heater control module located on a 2017-2018 Pacifica?
The auxiliary (rear) HVAC module is typically located in the rear of the vehicle, behind one of the interior trim panels in the cargo area, near the rear HVAC unit itself. Accessing it requires removing interior panels.
Can I replace this module myself?
A DIYer can perform the physical replacement of the module, which involves removing trim panels and swapping the part. However, the final, mandatory step of PROXI alignment requires specialized diagnostic tools that most DIYers do not own. You will need to plan a visit to a shop after you install the part.
My rear vents blow air, but it's not hot. Is it the module?
It could be the module, but you should check other things first. The most common cause of no heat is an air pocket in the cooling system or a low coolant level. Ensure your coolant reservoir is full. If the coolant level is fine, the problem could be the module or a faulty blend door actuator that the module controls.
Helpful Videos
Technical Specifications
OEM Part Numbers: 68226022 68226022AD 68226022AE 68226022AF 68226022AG
Controls rear HVAC blower motor and blend door actuators. Communicates on the vehicle's CAN bus network.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Chrysler Pacifica:
- 🎬 Helpful Videos
- 🛍️ Shop This Part
- Symptoms of a Failing Auxiliary Heater Control Module
- Known Issues, TSBs, and Recalls
- CRITICAL: Programming and Installation Requirements
- PROXI Alignment is Required
- Who Can Perform a PROXI Alignment?
- Buying a Used HVAC Auxiliary Heater Control Module
- Replacement Cost Breakdown
- Frequently Asked Questions (FAQ)
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