Powertrain, generic (extended)

P2CBE PCV Heater B Control Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2CBE says the switched control line of PCV heater B carries too high a voltage, usually because it touches battery positive. Since the module normally completes the heater circuit by pulling this line to ground, a short to supply means the output can no longer switch the element on, or the driver shuts down to protect itself, so heater B stays cold. No manufacturer documents P2CBE publicly. GM checks the A-side equivalent P053C on 2016 diesels with the same 20-of-40 sample counter below 90 °C as its open and ground tests, Type C; the Saab 9-5 2.0 diesel looks for 3–4 V on the low reference with the connector unplugged. Look for chafed insulation near hot parts. Note that in the B group the High code comes before Low.

Likely causes

Control wire chafed through and touching battery voltage
Moisture bridging pins in the heater B connector
Internal short in heating element B
Damaged output stage in the engine control module

Symptoms

  • Code stored, MIL depending on manufacturer
  • Heater B inactive, risk of an iced ventilation path in frost

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–200
Time0.5–2 h

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

Parts involved

pcv heater bwiring harnessecm

Related codes

P2CBDP2CBFP2CC0P053C

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