Powertrain, generic (extended)

P2BDA Motor Electronics Coolant Temperature Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2BDA is set when the sensor B signal in the electronics coolant loop falls below its valid window. These sensors are normally NTC thermistors, so a low voltage translates into an impossibly hot reading; a signal wire touching ground or a shorted sensor is the classic cause. No manufacturer documents P2BDA publicly. On sensor A of GM's 2013 Two-Mode hybrid trucks, the low fault P0A02 sets when the converted value reaches 162.1 °C in 30 of 50 samples taken every 100 ms, after propulsion has been active for more than 10 s; it is Type B. CARB requires such inputs to be tested against their valid limits. The opposite fault is P2BDB. The system may cut power because it believes the electronics are overheating.

Likely causes

Signal wire of sensor B shorted to ground
Internally shorted sensor B
Moisture in the sensor connector creating a leakage path to ground
Faulty input stage in the evaluating module

Symptoms

  • Check engine light and hybrid system warning
  • Scan tool shows an implausibly high electronics coolant temperature
  • Power reduction even with a cold vehicle

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–500
Time0.5–2.5 h

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

Parts involved

motor electronics coolant temp sensor bwiring harnesshybrid control module

Related codes

P2BD8P2BD9P2BDBP2BDEP0A02

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