Powertrain, generic · Vehicle speed, idle control and auxiliary inputs
P053B PCV Heater A Control Circuit Low
Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo
The PCV heater is an electric element of a few ohms (Saab: 6–10 Ω) at the junction of the ventilation hose and the intake; it stops water in the blow-by gas from freezing and blocking the ventilation in frost. The module switches it to ground. P053B means the low-side control line is shorted to ground, so the heater stays on regardless of command – it works in frost, but heats permanently. GM's diesels of 2016 check it with 20 of 40 samples below 90 °C coolant without warning lamp, GM Europe's 2.0 CDTI in the Saab 9-5 with the lamp on the first trip – a difference even within GM.
Likely causes
Control line chafed against ground
Heating element shorted to its housing
Engine module driver shorted
Symptoms
- Check engine light (depending on the maker)
- Heater permanently on
- Usually no change in driving
Repair estimate
DifficultyEasyDIY possible
Parts and labour€0–250
Time0.3–1.5 h
Typical range across vehicles; the real cost depends on what the testing finds.
Parts involved
pcv heaterheater wiringengine control module
Related codes
References: gsi.ext.gm.com, saabwisonline.com.