PowertrainP20B4

Caution

Severity: Caution - get it checked when you can

Reductant Heater Coolant Control Valve Circuit High

24 brands affected · Generic SAE J2012 description.

Key terms: Control module: a small computer that runs one part of the car · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions

Safety: This code relates to engine cooling or temperature. Overheating can damage the engine.

1What it means in plain English

The engine or powertrain control system has stored a fault that does not have specific guidance in this database yet.

2Common causes

Sensor or actuator fault
Wiring or connector fault
Vacuum or intake leak
Fuel or ignition problem
Control module fault

3Can I drive?

Caution · drive with care

Watch the temperature gauge. Stop safely and let the engine cool if the gauge climbs, steam appears, or a red warning light comes on.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 24

Brand	Code	Description	System
Ashok Leyland CV	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
BAIC Motor	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Mercedes-Benz	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
BYD	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Chery	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Daewoo	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
DFFS	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
DFFX	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
DFXK	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
EOBD	P20B4	Reductant heater coolant control valve circuit high Brand	Powertrain
Geely	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
GM	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Great Wall	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Hafei	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Holden	P20B4	Diesel Exhaust Fluid (DEF) Heater Valve Circuit High Voltage Brand	Powertrain
Hyundai	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
Isuzu	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
Land Rover	P20B4	Reductant heater coolant control valve - circuit high Brand	Powertrain
Opel	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Peugeot	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
Saab	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
MG (SAIC)	P20B4	Reductant Heater Coolant Control Valve Circuit High Brand	Powertrain
Smart	P20B4	Reductant Heater Coolant Control Valve Circuit High SAE	Powertrain
Toyota	P20B4	Reductant heater coolant control valve circuit high Brand	Powertrain

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Extended variant codes 2

These 7-character codes are manufacturer-specific variants of P20B4 and may be reported by some scan tools.

Brand	Code	Description	System
Mercedes-Benz	P20B400	Der Ausgang für Absperrventil des Kühlmittels hat Kurzschluss nach Plus. Brand	Powertrain
Mercedes-Benz	P20B412	Der Ausgang für Absperrventil des Kühlmittels hat Kurzschluss nach Plus. Es liegt ein Kurzschluss nach Plus vor. Brand	Powertrain

6Related codes

Browse Pxxx codes or P20Bxx codes.