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.
Medium severity. Can I keep driving?If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
Symptoms
- Check engine light (depending on the maker)
- Heater permanently on
- Usually no change in driving
Most likely causes
- Control line chafed against ground
- Heating element shorted to its housing
- Engine module driver shorted
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: easy
- It affects emissions.
What each character of P053B means
- P: Powertrain: engine and transmission
- 0: Generic code: same on every make
- 5: Speed and idle
- 3B: Specific fault in that system
Frequently asked questions
Can I keep driving with code P053B?
If the car is running normally, drive in moderation to a repair shop. If it loses power or another warning appears, do not continue.
What causes code P053B?
The most common causes are: control line chafed against ground; heating element shorted to its housing; engine module driver shorted.
Related codes
- P053APCV Heater A Control Circuit/Open
- P053CPCV Heater A Control Circuit High
- P053DPCV Heater A Performance
- P052EPCV Regulator Valve Performance
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.