Overview

Used HVAC control unit designed for Citroën C4 Picasso and Grand Picasso models (vehicles up to 2013). This unit controls heating, ventilation and air conditioning functions from the dashboard panel, including blower speed, temperature regulation, mode selection and automatic climate features where applicable. Frequently searched by product codes 9659627477, 9659627477-00 or 6451WV.

Function And Benefits

• Precise Control: Manages blower motor speeds, temperature blend doors and climate modes for efficient cabin comfort.
• Integrated Electronics: Communicates with vehicle CAN networks to coordinate A/C compressor, recirculation flap and rear climate systems (if fitted).
• Direct Replacement: Matches original equipment form and connector layout for straightforward fitment on compatible models.
• Cost Effective Repair Option: Replaces faulty dashboard climate controller without needing to replace entire HVAC assembly.

How To Replace

Replacement can be carried out by a competent mechanic or an experienced DIYer. Typical steps:

• Disconnect Battery: Always isolate the vehicle battery before starting work to prevent electrical damage and airbag/ECU faults.
• Remove Trim: Carefully remove surrounding dash trim and facia panels to access the control unit. Use plastic trim tools to avoid damage.
• Unplug Connectors: Release and unplug multi-pin connectors from the rear of the unit. Inspect connectors for corrosion or bent pins.
• Unscrew Unit: Remove mounting screws and extract the control module from the dash.
• Install Replacement: Fit the new unit, secure with screws, reconnect harnesses and reassemble trim. Reconnect battery and verify functionality of all climate controls.
• Post-Fit Checks: Verify blower operation, temperature adjustment and AC compressor engagement. On vehicles with automatic climate control, allow system to complete its self-check routines.

Technical Information

• Manufacturer: Stellantis (Citroën/Peugeot)
• Model: Citroën C4 Picasso, Citroën C4 Grand Picasso (up to 2013)
• Product Codes: 9659627477, 9659627477-00, 6451WV
• Additional Numbers: HW 06.00, SW 07.00, NFP

Installation Recommendations

• Disconnect Battery: Always disconnect the battery before removal and installation to prevent damage to electronic modules.
• Inspect Connectors: Check wiring harness and connectors for corrosion, water damage or broken pins; poor contacts are a common cause of malfunction.
• Use Correct Tools: Use trim removal tools and torque screws to manufacturer recommendations to avoid cracking dash components.
• Professional Diagnostics: If functions are intermittent after fitment, perform a full system scan with Stellantis-compatible diagnostic equipment to read fault codes and sensor data.

Why This Part Most Commonly Fails

Common failure causes for HVAC control units include moisture ingress, worn or oxidised connector pins, failed internal switches or potentiometers, degraded display elements, and cracked solder joints from thermal cycling. Intermittent operation frequently arises from poor electrical contact at connectors or internal cold solder joints. Regular exposure to cabin humidity and temperature changes accelerates wear.

Compatibility And Notes

This control unit is typically fitted to Citroën C4 Picasso and Grand Picasso models produced up to 2013 and is commonly referenced by the codes listed above. When searching for replacements, customers often use the product numbers 9659627477, 9659627477-00 or 6451WV.

Who Should Fit This

Recommended for professional fitment by automechanics or experienced DIYers familiar with dashboard disassembly and vehicle electronics. If in doubt about diagnostics or post-fit issues, use workshop diagnostic tools to confirm correct operation and clear any related fault codes.