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U069C Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 3

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

U069C refers to the third temperature probe in the bank 2 exhaust path, so it can only occur where each cylinder bank feeds its own aftertreatment line, as on some V engines. Such a probe is a digital unit that reports its reading as SENT or CAN frames; the code is stored when those frames stop or keep failing their checks. No manufacturer documents U069C publicly. GM's 2025 diesels have one bank and test only the bank 1 positions, declaring a probe lost after 19 bad samples within 25 and rating it Type A. Bentley's V8 bulletin 2065698/1 proves that digital bank 2 probes are in use, yet names only the first position (U0621). An analog probe at this spot reports through P2466 to P246A, and the fourth probe on bank 2 has U069D. The MIL and a postponed filter regeneration are the likely consequences.

Likely causes

Sensor harness on the bank 2 exhaust side chafed or heat-damaged

Electronics box of the probe failed

Probe has lost its supply or ground

Connector corroded or not latched

Symptoms

Check engine light
Filter regeneration on bank 2 postponed or blocked
Probe shows no value in live data

Repair estimate

DifficultyMediumDIY possible

Parts and labour€60–450

Time0.5–2 h

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

Parts involved

egt sensor bank 2 sensor 3vehicle bus wiring

References: law.cornell.edu, gsi.ext.gm.com, static.nhtsa.gov.