Powertrain, generic · Hybrid propulsion

P0CB2 Hybrid/EV Battery Temperature Sensor O Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0CB2 is the catch-all electrical code for battery temperature sensor O, reserved for circuit faults that are not classified as low, high or erratic. Publicly, no manufacturer documents this exact code. Counting the rationality list in GM's 2011 Volt table puts O in position 15 of 16, but GM only uses P0CB3 to P0CB6 for it. Mitsubishi maps O to module sensor [14] of the Outlander PHEV and likewise relies on the rationality, short and open codes alone. CARB section (e)(15.2.3)(A)(iv) counts battery temperature sensors among the inputs that have to be monitored, and (A)(v) asks for codes that point to the smallest replaceable unit. With O unusable, the controller has to guess the module temperature and normally cuts battery power. The thermistor sits inside the pack, so repair is a high-voltage job.

Likely causes

Poor contact at the sensor O connector on the monitoring board
Damaged lead between thermistor O and the board
Faulty measuring channel in the cell monitoring unit

Symptoms

  • Hybrid or EV system warning, possibly with check-engine lamp
  • Reduced electric power or charging rate

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€150–2,500
Time1–5 h

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

Parts involved

hv battery temp sensor owiring harnessbms

Related codes

P0CB3P0CB4P0CB5P0CB6P0CADP0CB7

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