Powertrain, generic · Hybrid propulsion

P0CD6 Hybrid/EV Battery Pack Coolant Temperature Sensor B Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P0CD6 means that coolant temperature sensor B at the battery outlet is electrically fine, yet its value does not fit the rest of the thermal system. GM runs the check in the hybrid controller of the Volt with the coolant pump above 20 % and no circuit faults present: if the outlet reading is more than 10 °C away from both the inlet reading and the mean cell temperature (2011 Volt, 80 of 100 samples at 100 ms), or at least 20 °C in the 2016 ELR (32 of 40 samples at 250 ms, pump running for over a minute), the result is a Type B code with the MIL following on the second trip. Volvo lists ECM-P0CD623 on the 2016-17 XC90 T8 as an incorrect entry cured by a total software upgrade (TJ 32193). Otherwise a drifting sensor, contact resistance or trapped air are likely.

Likely causes

Outlet coolant temperature sensor reading off (drift)
Contact resistance at connector or terminals
Air or low coolant in the battery loop after service
Control module software sets the code incorrectly (e.g. Volvo XC90 T8)

Symptoms

  • MIL on, often without noticeable driving symptoms
  • Battery cooling or heating behaves unexpectedly

Repair estimate

DifficultyHardWorkshop job
Parts and labour€0–400
Time0.5–2.5 h

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

Parts involved

hv battery pack coolant temp sensor bwiring harnessbms

Related codes

P0CD5P0CD7P0CD8P0C43P0A9C

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.