Powertrain, generic · Hybrid propulsion

P0C70 Hybrid/EV Battery Temperature Sensor C/D Correlation

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C70 is the correlation check between battery temperature sensors C and D. The controller expects both to settle at nearly the same value once the pack has rested, and it stores the code when their difference stays too large. No manufacturer documents P0C70 publicly. Where GM and Mitsubishi publish this monitor, they compare each sensor with the pack average and name the single sensor; GM's sensor 4 code P0AE9 is the D counterpart. Before replacing parts it is worth knowing that GM cured false sets of these Volt sensor codes, shown with a battery-too-cold message, by reprogramming the module (18-NA-342). Genuine faults are a drifting thermistor, a sensor that lost contact with its cells, or uneven cooling. The battery controller usually limits power. P0C71 continues with D/E.

Likely causes

Thermistor C or D drifted out of agreement with the other
Battery control software that sets the code falsely, for example in cold weather
Sensor C or D detached from its cell group
Uneven cooling across the pack, such as a blocked air duct or coolant channel

Symptoms

  • Malfunction indicator lamp or EV system warning
  • Message asking to plug in or warm the battery
  • Reduced electric power and slower charging

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,500
Time0.5–6 h

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

Parts involved

hv battery temp sensor chv battery temp sensor dbms

Related codes

P0C6FP0C71P0ACBP0AE9

References: static.nhtsa.gov, gsi.ext.gm.com, mitsubishitechinfo.com.