DTC    P0031    Oxygen (A/F) Sensor Heater Control Circuit Low (Bank 1 Sensor 1) DTC    P0032    Oxygen (A/F) Sensor Heater Control Circuit High (Bank 1 Sensor 1)

HINT: Parameters listed in the chart may be different from your readings depending on the type of instruments and other factors. If any DTCs are displayed during a check mode, check the circuit for the DTCs listed in the chart below. For details of each DTC, refer to the page indicated.

HINT: Using the intelligent tester's Data List allows switch, sensor, actuator, and other item values to be read without removing any parts. Reading the Data List early in troubleshooting is one way to save time.

FAIL-SAFE CHART If any of the following DTCs are set, the ECM enters fail-safe mode to allow the vehicle to be driven temporarily.

When troubleshooting Europe On-Board Diagnostic (Euro-OBD) vehicles, the vehicle must be connected to an OBD scan tool (complying with ISO 15765-4). Various data output from the vehicle's ECM can then be read. Euro-OBD regulations require that the vehicle's on-board computer illuminate the Malfunction Indicator Lamp (MIL) on the instrument panel when the computer detects a malfunction in:

HINT: Each ECM terminal's standard voltage is shown in the table below. In the table, first follow the information in "Condition". Look at "Symbols (Terminal No.)" for the terminals to be inspected. The standard voltage between the terminals is shown in "Specified Condition". Use the illustration above as a reference for the ECM terminals.

Use the table below to help determine the cause of the problem symptom. The potential causes of the symptoms are listed in order of probability in the "Suspected area" column of the table. Check each symptoms by checking the suspected areas in the order they are listed. Replace parts as necessary.

NOTICE: When an injector is replaced, the injector's compensation code must be input into the ECM (proceed to "INPUT INJECTOR COMPENSATION CODE(S) INTO ECM" procedures below).

Diesel Clean Advanced Technology (TOYOTA D-CAT) comprehensively regulates engine control (consists of a catalytic system and a fuel injection system) that purifies both particulate matter (PM) and nitrogen oxides (NOx) discharged by diesel engines. The catalytic system purifies hydrocarbons (HC) and carbon monoxides (CO), and reduces PM and NOx with a catalytic converter with the Diesel Particulate-NOx Reduction system (DPNR)