BK2Q-9K546-AG — Technical Research
Siemens VDO / Continental piezo common-rail injector for the Ford 2.2 TDCi Duratorq 'Puma' (P22DTE) diesel, also used on Land Rover Defender 2.2 and PSA 2.2 HDi. Ford OE BK2Q-9K546-AG; Continental A2C59517051; Siemens 5WS40745; Land Rover LR032067. NOT the same as the later 2.0 EcoBlue injector - match by old part number + engine code, not vehicle badge. Key symptoms: Hard starting / extended cranking; Rough running, knocking or rattling; Limp mode / loss of power; Low fuel rail pressure / pressure-regulation codes. Common failure modes: Excessive spill / back-leakage; Piezo stack degradation / control fault; Nozzle coking / poor atomisation.
Siemens VDO BK2Q-9K546-AG (A2C59517051 / 5WS40745) Ford 2.2 TDCi Puma Piezo Injector
Siemens VDO / Continental piezo common-rail injector for the Ford 2.2 TDCi Duratorq 'Puma' (P22DTE) diesel, also used on Land Rover Defender 2.2 and PSA 2.2 HDi. Ford OE BK2Q-9K546-AG; Continental A2C59517051; Siemens 5WS40745; Land Rover LR032067. NOT the same as the later 2.0 EcoBlue injector - match by old part number + engine code, not vehicle badge. Key symptoms: Hard starting / extended cranking; Rough running, knocking or rattling; Limp mode / loss of power; Low fuel rail pressure / pressure-regulation codes. Common failure modes: Excessive spill / back-leakage; Piezo stack degradation / control fault; Nozzle coking / poor atomisation.
A leaking piezo injector with high spill return drops rail pressure during cranking so the engine struggles to fire.
An out-of-balance injector under/over-fuels its cylinder, producing a knock or diesel rattle.
Rail-pressure or injector-control faults trigger an ECU derate to protect the fuel system.
Excessive injector spill (back-leakage) prevents the system holding target rail pressure.
Poor atomisation from a worn or coked nozzle.
A single failing injector raises consumption and produces a cylinder-specific stumble.
- WarningMatch the OLD injector part number AND the engine code before ordering - the 2.2 Puma uses Siemens here, while other Ford diesels (and the later 2.0 EcoBlue) use different injectors. Do not order by vehicle badge alone.
- InstallationAfter fitting, programme the injector correction/coding values with Ford IDS or Land Rover diagnostics, or the engine will run rough and may misfire.
- MisdiagnosisBefore condemning injectors, run a leak-off (spill return) test and check the fuel rail pressure sensor - low rail pressure faults are often blamed on injectors.
- InstallationAlways renew the copper sealing washer, clean the bore, and torque the clamp to spec to prevent combustion blow-by.
- TipReplace the fuel filter and check for fuel contamination before fitting replacement injectors to protect the new units.
- TestingThese are Continental/Siemens VDO piezo injectors - test on a Siemens/VDO-capable common-rail bench, not a Bosch-only bench.
What is injector BK2Q-9K546-AG?+
A Siemens VDO / Continental piezo common-rail diesel injector for the Ford 2.2 TDCi Duratorq 'Puma' (P22DTE) engine. Continental number A2C59517051, Siemens 5WS40745, Land Rover LR032067.
Which vehicles use BK2Q-9K546-AG?+
Ford Transit and Transit Custom 2.2 TDCi (2011-2016) and Land Rover Defender 2.2 Puma, plus PSA 2.2 HDi vans (verify by VIN).
Is this a Bosch or Siemens injector?+
It is a Siemens VDO / Continental piezo injector. Some other Ford 2.2 diesels use Bosch, so match by the old part number and engine code.
Is it a piezo or solenoid injector?+
It is a piezoelectric injector and needs a Siemens/VDO/Continental-capable test bench.
What is the Continental number for BK2Q-9K546-AG?+
A2C59517051 (Siemens 5WS40745); Land Rover lists it as LR032067.
Does BK2Q-9K546-AG fit the 2.0 EcoBlue?+
No. This is the 2.2 TDCi Puma injector. The later 2.0 EcoBlue uses a different injector - confirm by engine code, not vehicle badge.
Do I need to code the injector after fitting?+
Yes. Programme the injector correction/coding values with Ford IDS or Land Rover diagnostics after replacement, or the engine will run rough.
What are the symptoms of a failing BK2Q-9K546-AG?+
Hard starting, rough running/knock, limp mode, low rail-pressure codes, smoke and higher fuel consumption.
Why does my 2.2 TDCi go into limp mode?+
Excessive injector spill (back-leakage) lowers rail pressure and triggers a protective derate. A leak-off test confirms a leaking injector.
Can I test BK2Q-9K546-AG on a Bosch bench?+
No - it is a Siemens VDO piezo injector and requires a Siemens/VDO/Continental-capable bench.
Should I replace one or all injectors?+
Diagnose each with a leak-off test and live correction values; on high-mileage Transit/Defender engines failures often cluster, so check all.
Why check the fuel filter before fitting?+
Fuel contamination is a common cause of failure; replacing the filter and clearing contamination protects the new injectors.
Why renew the copper washer?+
It is a one-use crush seal; reusing it risks combustion blow-by and carbon build-up around the injector base.
Does a remanufactured BK2Q-9K546-AG perform like new?+
A properly remanufactured piezo injector is bench-tested and recalibrated to the Siemens plan to meet original delivery and spill specs.