Powertrain, generic (extended)

P2465 Diesel Particulate Filter Differential Pressure Too High (Bank 2)

Check engine lightOn

EmissionsRelevant

Drive cycleRequired

Limp modePossible

P2465 means the second particulate filter builds up more back pressure than the controller accepts for the exhaust flow it calculates. The code is only possible where each cylinder bank has its own filter. No maker documents the bank 2 version in a public table; its bank 1 twin P244B gives the logic. On GM's 3.0 L LZO that check also reacts to a loose or leaking downstream pipe, comparing either the downstream pressure or the pressure-to-flow ratio, and it is a Type A fault there. CARB asks for monitoring that recognises a filter loaded so heavily that it endangers the engine. Typical findings are a filter packed with soot or ash, a plugged rear hose, a dented pipe or a sensor reading too high. A soot-model warning without a pressure test is P243F, and the stage with forced power reduction on this bank is P243B.

Likely causes

Bank 2 filter heavily loaded with soot or ash

Downstream sensing hose blocked, kinked or swapped

Dented or obstructed exhaust pipe behind the filter

Differential pressure sensor drifting high

Symptoms

MIL on
Frequent or prolonged regeneration attempts
Loss of power, possibly limp mode

Repair estimate

DifficultyMediumWorkshop job

Parts and labour€0–2,500

Time0.3–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

dpf b2dpf diff pressure sensordpf pressure lines

Related codes

P2464 P244B P2455 P243F P243B

References: law.cornell.edu, gsi.ext.gm.com.