The Magneti Marelli IAW 6LP2.12 Engine Control Unit (ECU) is a direct-fit engine management module designed for PSA Group vehicles equipped with the 1.4 16V KFU engine. This unit manages fuel injection, ignition timing and sensor diagnostics to ensure efficient engine operation. Commonly searched by its part numbers (9664339980, 9665936280, 16.631.064, 16.988.004, 1940XH, 1940XJ), the IAW 6LP2.12 is a frequent replacement item for technicians and DIY enthusiasts working on Citroën and Peugeot models.

Technical Information

• Manufacturer: Magneti Marelli
• Model: IAW 6LP2.12
• Product Codes: 9664339980, 9665936280
• Additional Numbers: 16.631.064, 16.988.004, 1940XH, 1940XJ

Compatibility: Fits vehicles equipped with the 1.4 16V KFU engine family for Citroën and Peugeot. This specific unit was removed from a Citroën C4 (2009). When searching, use the listed part numbers for the highest chance of matching exact variants.

Function And Common Symptoms

The ECU controls fuel delivery, ignition timing, idle control and interprets signals from sensors such as MAF, MAP, TPS, coolant temperature and crankshaft position. When the ECU malfunctions, typical symptoms include engine not starting, intermittent stalling, misfires, rough idle, reduced performance, poor fuel economy, illuminated check engine light and sometimes immobilizer or key recognition faults.

Most Common Causes Of Failure

• Moisture Ingress Or Corrosion: Water ingress or corroded connectors lead to short circuits and progressive failure.
• Thermal Stress And Aging: Repeated heat cycles or degraded solder joints can cause component failure.
• Electrical Surges Or Faulty Wiring: Voltage spikes, poor grounding or damaged wiring harnesses transmit damaging currents to the ECU.
• Mechanical Damage: Physical impacts or improper handling during removal/installation.

Installation Recommendations

• Disconnect The Negative Battery Terminal Before Starting Work To Avoid Short Circuits And Protect Vehicle Electronics.
• Observe ESD Precautions: Avoid Static Discharge By Grounding Yourself When Handling The Unit.
• Inspect Wiring And Connectors: Repair Corroded Pins, Replace Damaged Sockets And Check All Ground Points And Fuses Before Fitting The ECU.
• Fit Securely And Ensure Seals Are Intact To Prevent Moisture Ingress.
• After Installation, Program Or Pair The Unit As Required: Many ECUs Need Immobilizer Coding Or Software Configuration To Match The Vehicle—use appropriate diagnostic tools.
• Verify Operation: Clear Fault Codes, Perform A Road Test And Monitor Live Sensor Data To Confirm Proper Function.

Notes For Mechanics And DIYers: Keep the relevant part numbers handy when ordering or searching. Replacing the ECU is often straightforward mechanically, but software matching and electrical diagnosis require appropriate diagnostic equipment and experience. Address underlying causes such as wiring or sensor faults to avoid repeated failures.

As a critical part of the engine management system, the control unit regulates fuel injection and optimizes engine performance, ensuring efficient operation and reduced emissions. With its advanced technology, it plays a vital role in vehicle functionality, affecting acceleration, fuel efficiency, and overall driving experience.

When considering a replacement, it’s important to be aware that control units like the IAW 6LP2.12 may fail due to electrical issues, moisture ingress, or manufacturing defects. Regular inspections of your vehicle’s electronic components can prevent unexpected failures.

Technical Information:

• Manufacturer: Magneti Marelli
• Model: IAW 6LP2.12
• Product Codes: 9665936280, 9664339980
• Other Numbers: 16.631.064, 1607022280, 1607022380