Peugeot and Citroen 1.6 HDi Common Faults: BSI, Injectors, EGR and Turbo

A Peugeot 207 1.6 HDi will not start, turns over fine, no fuel pump prime you can hear, and the customer says it did this once before and “fixed itself” after a few tries. On the DV6 1.6 HDi range fitted across Peugeot and Citroen’s smaller cars and vans, that pattern usually points at the fuel pump relay built into the BSI, not the pump itself.

BSI and fuel pump relay issue

The BSI, the body control unit that also handles the fuel pump relay function on these cars, develops dry solder joints or relay wear over time, and the fuel pump stops getting a reliable feed. It is intermittent by nature, which makes it one of the more frustrating faults to catch on the ramp if the car starts fine every time you have it in. Tapping the BSI while cranking a non-starting car is a rough but genuinely useful first check. A confirmed BSI relay fault means either a repaired BSI or a replacement, and either way it is a job that needs proper coding to the car afterwards, not a straight swap.

Injector seal leaks

Same story as most common rail diesels of this era: injector seals weep, you get a diesel smell, sometimes a slightly rough idle, and it is worth checking before assuming an injector itself has failed. Seals are cheap, the labour is straightforward on the 1.6 HDi compared to some larger engines, generally an hour or two per injector.

EGR and DPF clogging

These small diesels do a lot of city and short-trip work across their life, particularly the Citroen C3 and Peugeot 207/208 versions, and that means EGR and DPF clogging is common. P0401 and P2463 turn up often. A stuck EGR valve causes rough idling and hesitation under light load even before the DPF light comes on, so check the EGR before assuming the DPF is the only issue. Where the customer wants both removed for good, that is an EDC17C10 or EDC16C34 file depending on year, alongside the physical parts coming out.

Turbo actuator faults

The electric turbo actuator on later DV6 variants can stick or lose calibration, giving a flat spot, a whining noise on start-up as it tries to home, or a permanent limp mode. Recalibrate first with a scan tool before ordering a new actuator; a fair few of these come right once the actuator is told to relearn its end stops properly.

Common rail pressure sensor faults

A car that suddenly goes into limp mode with no obvious drivability warning beforehand, full power loss but the engine still idling normally, is worth checking for a common rail pressure sensor or regulator fault before assuming a mechanical failure. These can trigger a P0087 or P0193 and put the ECU straight into a protective low-power mode. It is a sensor and wiring check first, not a fuel system strip-down, and catching it early avoids an unnecessary pump replacement. A quick check of the connector and loom near the rail is worth doing before condemning the sensor itself, corrosion and chafing in that area cause the same symptom.

Checklist before you quote the job

• Intermittent no-start: check the BSI fuel pump relay before condemning the pump
• Diesel smell, slightly rough idle: leak-off test the injectors before assuming a bigger fault
• Rough idle and hesitation with no DPF light yet: check the EGR valve first
• Flat spot or whining turbo: recalibrate the actuator before replacing it
• Sudden limp mode with no warning: check the rail pressure sensor before condemning the pump

File details for the ECUs on this range are on the EDC17C10 page, and the Peugeot and Citroen brand pages cover the rest of the shared PSA range.