Powertrain, generic (extended)

P2BDF Motor Electronics Coolant Temperature Sensor C Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2BDF is stored when the signal of coolant temperature sensor C climbs to nearly the full reference voltage. For the module this looks like coolant colder than any climate allows; in practice a pin that has backed out of the connector, a corroded or broken signal wire, or a short to a voltage source is behind it. No manufacturer documents P2BDF publicly. GM sets the matching code for its single electronics coolant sensor, P0CF1, above 98 % of the 5 V reference (4.9 V): 16 of 20 samples at 250 ms in the 2011 Volt tables, 4 s within a 5 s window in the 2019 tables, Type B in both. CARB requires out-of-range checks on all inverter cooling inputs. The low counterpart is P2BDE, sensor B uses P2BDB. A warning lamp and reduced power are possible.

Likely causes

Backed-out or loose pin in the sensor C connector
Corroded or broken signal wire of sensor C
Open circuit inside sensor C
Signal wire shorted to the 5 V reference or another supply

Symptoms

  • Check engine or hybrid system warning
  • Live data shows the lowest possible temperature for sensor C
  • Pump and fan running in a fixed protective mode

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–500
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 cwiring harnesshybrid control module

Related codes

P2BDCP2BDDP2BDEP2BDBP0CF1

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