Peugeot P0203

Injector circuit Cylinder 3 on Peugeot 1.6/2.0 HDi — Siemens/Continental piezo injectors fail with age, plus chronic injector seal blow-by.

Peugeot P0203 — Injector circuit Cylinder 3 on Peugeot 1.6/2.0 HDi — Siemens/Continental piezo injectors fail with age, plus chronic injector seal blow-by. Typical UK independent garage cost: £220–£780.

What actually causes P0203 on a Peugeot

PSA 1.6 HDi (DV6) injectors are notorious for blowing their copper sealing washers — this allows combustion gas to leak past, fouling the injector body and eventually causing electrical faults on cyl 3 specifically (it sits where heat dissipation is worst). On 2.0 HDi DW10 the Bosch CRI2 injectors are more durable but still need replacement around 130k miles.

Peugeot engines that log P0203

• 1.6 HDi DV6 (208, 308, 3008, Partner)
• 2.0 HDi DW10 (407, 508, 3008, 5008, Expert)
• 1.4 HDi DV4 (107, 207)

How we diagnose P0203 on a Peugeot

1. Lexia / Diagbox — read injector correction values
2. Visually inspect injector well for carbon deposits ('black death')
3. Remove injector — if seized, use proper PSA injector puller (don't lever it)
4. Re-cut injector seat with PSA injector well cleaner tool
5. Fit new injector with new copper washer, code to ECU

The common misdiagnosis to avoid

Don't replace the injector before inspecting the copper sealing washer and injector well — a 'black death' of carbon around the injector base means the seal has failed; new injector without re-cutting the seat will leak again immediately.

Peugeot P0203 repair cost in the UK

Expect £220–£780 including parts and labour at an independent garage. Main-dealer quotes on Peugeot are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.

Bob's workshop tip

If you see 'black death' carbon around the injector base on a 1.6 HDi, warn the customer that the injector may seize in the head — quote for the worst case (broken injector, head removal, £1,500+) up front so there's no surprise mid-job.

Codes usually seen alongside P0203 on Peugeot

• P0201
• P0202
• P0204
• P1340

Symptoms drivers report with P0203

• Engine drops into limp mode at motorway speeds, then resets after a restart
• Slight knock or 'diesel knock' specifically when cold
• Loss of power above 2,500 RPM only
• Slightly elevated fuel consumption (1–3 MPG drop)
• Code returns within 100 miles of clearing

Repairs that clear P0203

• Injector replacement

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0203 guide.