Circuit Description

WARNING: This page is about a different car, the 2004 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

Refer to CIRCUIT DESCRIPTION under DTC P0136: OXYGEN SENSOR CIRCUIT MALFUNCTION (BANK 1 SENSOR 2).

HINT:

The ECM provides a pulse width modulated control circuit to adjust current through the heater. The heated oxygen sensor heater uses a relay on the +B side of the circuit.

Fig 1: Heated Oxygen Sensor Circuit Diagram

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Fig 2: DTC (P0037, P0038) Diagnosis Table

HINT:

Sensor 2 refers to the farther sensor from the engine body.