Network, generic

U0665 Lost Communication With Fuel Rail Pressure Sensor Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Engines with one fuel rail per cylinder bank may give each rail its own pressure sensor, and newer ones send the reading digitally via SENT. U0665 says the controller has lost the bank 2 sensor's data. GM's 23OBDG07 and 24OBDG07 tables pair it with GM's own code U101C: path 1 trips when the signal line stays at high level, path 2 when it stays low, each after 0.5 s and within one trip. An out-of-range raw value from the same sensor is logged separately (GM P312B), and the plausibility tests of P01BF run on top. The bank 1 sensor follows the same logic with U0625 and U101B. Analog bank 2 circuit faults are P01BE to P01C2. Without a rail pressure value the controller falls back to a substitute model; reduced power and rough running are possible.

Likely causes

Bank 2 sensor signal wire open or shorted to ground or voltage
Fuel-soaked, corroded or loose sensor connector
Rail pressure sensor electronics on bank 2 failed
Engine controller SENT input faulty

Symptoms

  • Check engine light after one trip
  • Reduced power, hesitation or rough running
  • GM-specific code U101C stored alongside

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–800
Time0.5–3 h

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

Parts involved

fuel rail pressure sensor bank 2vehicle bus wiring

Related codes

U0625P01BEP01BFP01C0P01C1P01C2

References: gsi.ext.gm.com, gsi.ext.gm.com, en.wikipedia.org.