P0030 HO2S Heater Control Circuit (Bank 1 / Sensor 1) - Automotive Repair Guides & Equipment

COMPONENT LOCATION

GENERAL DESCRIPTION

The normal operating temperature of the HO2S(Heated Oxygen Sensor) ranges from 350 to 850°C(662 to 1562°F). The HO2S heater greatly decreases the amount of time required for fuel control to become active. The ECM provides a pulse width modulated control circuit to adjust current through the heater. When the HO2S is cold, the value of the resistance is low and the current in the circuit is high. On the contrary, if the temperature in the resistor of the sensor rises, the current drops gradually.

DTC DESCRIPTION

Checking current from HO2S under detecting condition, if the heater current is below a certain threshold for more than predeterminate time, ECM sets P0030.

possible causes

1.	Poor Connection

2.	HO2S(B1/S1)

ECM

SPECIFICATION

(Reference only)

Condition	Current(A)
Heater Current at 13.5V, 450°C(842°F) Exhaust	0.5 ~ 1.1

DIAGNOSTIC CIRCUIT DIAGRAM

TERMINAL AND CONNECTOR INSPECTION

1.	Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.

2.	Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.

Has a problem been found?

	▶ Repair as necessary.
	▶ Go to ” Component Inspection ” procedure.

COMPONENT INSPECTION

■ Check HO2S(B1/S1) Heater resistance

1.	IG “OFF” and disconnect HO2S(B1/S1) connector

Measure resistance between power and control terminals of HO2S(B1/S1) heater(Component Side)

3.3 ~ 4.1[20°C(68°F)]

Is the measured resistance within specification?

▶ Substitute with a known – good ECM and check for proper operation.

There is a memory reset function on GDS that can erase optional parts automatically detected and memorized by ECM. Before or after testing ECM on the vehicle, use this function to reuse the ECM on the others

▶ Substitute with a known – good HO2S and check for proper operation.

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