How a Failing 2.7 TDV6 Injector Presents
On the V6 TDV6, a single failing injector has a complex signature because the V-block runs three cylinders per bank, each with its own rail. The most common symptom is a rough idle that resolves above 1,200 rpm — one cylinder on one bank is over- or under-fuelling. The second is a 'bank fault' on the dashboard that points to the wrong bank — the ECU detects rail-pressure deviation on bank A but the failed injector is actually on bank B, because the under-fuelling cylinder on B has reduced its rail's pressure draw and made bank A's rail look high by comparison. The third is a Discovery- or Range-Rover-specific transmission shudder under light load — the ZF gearbox is responding to the engine's combustion imbalance.
Diagnosis requires JLR SDD / Pathfinder or PSA DiagBox / Lexia depending on the vehicle — the Jaguar / Land Rover and Peugeot / Citroen calibrations are different and the ECU coding pages live in different menus. On the V6 specifically, never trust the 'bank A' or 'bank B' label in the fault code — read live cylinder fuel-trim values for all six and the failed cylinder's correction value will be at the negative limit.
