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U0693 Lost Communication With Humidity Sensor

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Intake air humidity influences combustion temperature and NOx, so some engines measure it, usually with a capacitive element built into the air-mass meter; Bosch offers such meters with optional humidity sensing over SENT, FAS or LIN. GM's dual-throttle tables 23OBDG07/24OBDG07 use U0693 for a SENT humidity sensor on bank 1, stored when the sensor itself reports a maximum or minimum error for 1 s, MIL after two trips; the same program has P00F4 to P00F6 for the reading and GM codes for invalid data. Other layouts avoid U0693: GM's 25OBDG04A treats a silent LIN air-mass meter as U060F, and Ford's 2023 diesel sets P00F2 for bad SENT humidity message timing. Fuel and EGR then run on default humidity.

Likely causes

Humidity element in the air-mass meter contaminated or failed
Signal or supply wire to the sensor faulty
Moisture or corrosion in the connector
Engine controller software fault

Symptoms

  • Check engine light after two trips
  • Usually no noticeable drivability change
  • Accompanying humidity or air-mass codes possible

Repair estimate

DifficultyEasyDIY possible
Parts and labour€60–400
Time0.3–1 h

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

Parts involved

humidity sensorvehicle bus wiring

Related codes

P00F2P00F3P00F4P00F5P00F6U060F

References: gsi.ext.gm.com, gsi.ext.gm.com, fordservicecontent.com, bosch-mobility.com.