2020 Peugeot Boxer: From P2112 Panic to Perfect—DIY in One Afternoon!
Everything came to a lurching halt one day when my 2020 Peugeot Boxer’s check engine light came on and the van went into limp mode, with reduced power and a sluggish throttle response. At idle, it seemed fine, but under load, the accelerator was unresponsive, and performance dropped significantly.
Using my trusty YOUCANIC scanner, I scanned for codes and ran active tests. I found the code P2112: “Throttle actuator stuck closed,” so I decided to run an Air Mixer Actuator Test, which displayed the message “Actuator jammed.”
I confirmed that the wiring wasn’t the problem by checking the voltage at the throttle body connector with a multimeter (using a 12V supply, 5V reference, and ground all present). Then, I removed and cleaned the throttle body flap, but the fault was still present when I scanned my van again. Live data on my YOUCANIC scanner confirmed that airflow, turbo pressure, and EGR values were normal, pointing me directly to the throttle body actuator itself.
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After inspecting the throttle body actuator (air mixer), I found that it had failed internally. The flap motor and/or position sensor inside the unit were no longer responding to ECU commands, which caused the actuator to jam, setting code P2112. Cleaning and wiring checks confirmed the issue was not carbon buildup or a power supply fault, but a defective throttle body assembly
I removed the faulty throttle body (air mixer) and replaced it with a new FoMoCo unit (PN 9847039280 / superseding 9806625280). Then, I cleaned all connectors with electrical contact cleaner and refitted them securely. After installation, I used my YOUCANIC scanner to reprogram the new throttle body using the function “Programming the air mixer stops” so that the ECU could relearn the flap’s open/closed positions. Finally, I cleared the fault codes and test-drove the van. My 2020 Peugeot Boxer was back up and running, good as new!
Bonus Tip
Always run the Air Mixer Actuator Test first. It will quickly tell you if the flap is jammed.
• Don’t try to power the actuator motor directly with 12 V; it uses ECU-controlled H-bridge logic.
• Replace the whole throttle body assembly — the motor and sensor are sealed and non-serviceable.
• After replacement, don’t skip the “Programming the air mixer stops” calibration, or the ECU may continue to set plausibility faults.
• Match parts by OEM number (9806625280 / 9847039280 / A2C85766300), not just pictures, as there are variations across Boxer/Relay/Ducato vans.
• Double-check connectors and wiring looms — bent pins or corrosion can mimic actuator failure.
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