P1240 on SEAT: How to Diagnose & Fix
P1240 — SEAT-specific definition
1 SEAT model · 1 documented issue · 1 critical · $300-$1,800 repair
P1240 on SEAT by model: symptoms, diagnosis and fix
The 1.6 TDI common-rail engine in Ibiza Mk4/5, Leon Mk2/3 (and across VW Group small diesels) suffers injector failure (Continental/Siemens VDO piezo injectors on the EA189 CAYB/CAYC) typically at 100,000-180,000 km. Symptoms: rough cold start, individual-cylinder misfire, sometimes back-leak overwhelming the rail pressure regulator. Injector copper washers often re-seal poorly after the first removal.
Common Symptoms
- rough cold start
- misfire
- limp mode
- fuel smell
How to Fix
Back-leak test (10 min) confirms diagnosis. Single injector replacement €300-€600 incl. coding. Full set (4) €1,000-€1,800. Use VW 507.00 spec oil and quality diesel from major-brand stations.
Sources for this issue (1)
P1240 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P1240 mean on a SEAT?
On SEAT, P1240: VAG (SEAT) defines P1240 as fault 17648 'Fuel Injector for Cylinder 4 (N33): Open Circuit'. Possible causes: fuse for injector, wiring harness issue, failed injector, failed ECM (Ross-Tech wiki, https://wiki.ross-tech.com/wiki/index.php/17648/P1240). On SEAT it is documented across 1 model: Ibiza.
How much does it cost to fix P1240 on a SEAT?
Published repair estimates on SEAT range from $300 to $1,800 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.