PSA DW12 2.2 HDi Injector Problems: Symptoms & Repair (UK)

The DW12 is PSA's larger diesel, found in the Peugeot 407/607 and Citroen C5/C6. It uses either Bosch or Denso injection depending on variant. The engine was also used in some Jaguar and Land Rover models.

Common DW12 injector failure symptoms

• Rough idle and vibration: Uneven fuel delivery from worn injectors.
• Black smoke under acceleration: Over-fuelling from degraded nozzles.
• Loss of power: The ECU limits output when injector deviation is detected.

Why DW12 injectors fail

• fuel contamination
• high-pressure wear cycles
• carbon buildup
• poor fuel quality
• internal valve wear

How to diagnose DW12 injector faults

1. Read fault codes: Connect an OBD-II scanner and note any injector-related codes (P0201–P0204, P2146, P2149). This identifies which cylinder is affected.
2. Perform a leak-off test: Disconnect the fuel return pipes and route into measuring containers. Run the engine at idle for 60 seconds. Compare volumes per cylinder against manufacturer spec.
3. Listen for injector tick: Use a mechanic's stethoscope on each injector body. A dead or irregular tick indicates a stuck or failing solenoid.
4. Check fuel rail pressure: Monitor live fuel rail pressure data via diagnostic tool. Low pressure can mimic injector symptoms and may indicate a fuel pump issue instead.
5. Inspect for external leaks: Check around injector seals for signs of fuel or combustion gas leakage. Black carbon deposits indicate a blown seal.
6. Cylinder balance test: Use diagnostic software to run a cylinder contribution test. This electronically disables each injector in turn to measure its effect on engine speed.

Fault codes linked to DW12 injector issues

• P0201-P0204 – Injector circuit malfunction
• P0087 – Fuel rail pressure too low

DW12 repair advice

Check whether your DW12 has Bosch or Denso injectors before ordering. Coding requirements vary by model year and vehicle brand.

DW12 injector replacement cost (UK)

• Per injector: £180 - £350
• Full set: £700 - £1,200
• Labour: £120 - £300

Compatible injector part numbers for DW12

• Bosch 0445110036 – Bosch injector for early DW12
• PSA 9641742880 – PSA OE reference

Vehicles using the DW12 engine

• Peugeot 407 (2004-2011)
• Citroen C5 (2004-2008)
• Citroen C6 (2005-2012)
• Jaguar X-Type (2003-2009)

Find your exact DW12 injector by registration

Frequently asked questions

Is the DW12 used in Jaguars?

Yes. The Jaguar X-Type 2.2D uses a variant of the PSA DW12 engine with the same Bosch injectors.

How much does DW12 injector replacement cost?

A set of four costs £400-£700. Labour is 2-4 hours.

How much does it cost to replace injectors?

Replacement typically costs £150–£350 per injector depending on brand and engine. A full set of four with professional fitting usually costs £600–£1,200.

Can I drive with a faulty injector?

Driving with a faulty injector can cause engine damage, increased fuel consumption, DPF contamination, and oil dilution. We recommend diagnosis and replacement as soon as possible.

Do new injectors need coding?

Some vehicles require injector coding after replacement using manufacturer-specific diagnostic tools. Many Bosch solenoid units are plug and play. Check your engine guide for specific requirements.