Check Any Other Dtcs Output In Addition To Dtc P Or P

(a) Connect the intelligent tester to the DLC3.

(b) Turn the ignition switch ON and turn the tester ON.

(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC INFO / CURRENT CODES.

Result

Result

Display (DTC Output)

Proceed To

P0171 or P0172

A

P0171 or P0172 and other DTCs

If any DTCs other than P0171 or P0172 are output, troubleshoot those DTCs first.

GO TO DTC CHART

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (A/F CONTROL)

Connect the intelligent tester to the DLC3. Start the engine and turn the tester ON. Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds. On the tester, select the following menu items: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL.

Perform the A/F CONTROL operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume). Monitor the output voltages of A/F and HO2 sensors (AFS B1S1 and O2S B1S2) displayed on the tester. Result:

The A/F sensor reacts in accordance with increases and decreases in the fuel injection volume: +25 % = Rich output:

Less than 3.0 V -12.5 % = Lean output: More than 3.35 V NOTICE:

The A/F sensor has an output delay of a few seconds and the HO2 sensor has a maximum output delay of approximately 20 seconds.

Case

A/F Sensor (Sensor 1) Output Voltage

HO2 Sensor (Sensor 2) Output Voltage

Main Suspected Trouble Areas

Output Voltage More than 3.35 V Less than 3.0 V

Output Voltage More than 0.5 V Less than 0.4 V

Output Voltage Almost no reaction

Output Voltage More than 0.5 V Less than 0.4 V

A/F sensor A/F sensor heater A/F sensor circuit

Case

A/F Sensor (Sensor 1) Output Voltage

HO2 Sensor (Sensor 2) Output Voltage

Main Suspected Trouble Areas

3

Injection volume +25 % -12.5 %

Injection Volume +25 % -12.5 %

Extremely rich or lean actual air-fuel ratio

• Injector leakage or blockage

• Gas leakage from exhaust system

• Fuel pressure

• Air induction system

• PCV hose connections

Output Voltage Almost no reaction

-NG

Output Voltage Almost no reaction

-NG

Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.

To display the graph, select the following menu items on the tester: DIAGNOSIS / ENHANCED OBD II / ACTIVE TEST / A/F CONTROL / USER DATA / AFS B1S1 and O2S B1S2; then press the YES button and then the ENTER button followed by the F4 button.

Result

Result

Proceed To

Case 1

C

Case 2

B

Case 3

Go to step 11

Go to step 15

READ VALUE USING INTELLIGENT TESTER (MAF)

(a) Connect the intelligent tester to the DLC3.

(b) Turn the ignition switch ON and turn the tester ON.

(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF and COOLANT TEMP.

(d) Allow the engine to idle until the COOLANT TEMP reaches 75°C (167°F) or more.

(e) Read the MAF with the engine in an idling condition and at an engine speed of 2,500 rpm.

Standard:

MAF while engine idling: Between 1 g/sec. and 3 g/ sec. (shift position: N, A/C: OFF). MAF at engine speed of 2,500 rpm: Between 2 g/ sec. and 6 g/sec. (shift position: N, A/C: OFF).

REPLACE MASS AIR FLOW METER

READ VALUE USING INTELLIGENT TESTER (COOLANT TEMP)

(a) Connect the intelligent tester to the DLC3.

(b) Turn the ignition switch ON and turn the tester ON.

(c) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.

(d) Read the COOLANT TEMP twice, when the engine is both cold and warmed up.

Standard:

With cold engine: Same as ambient air temperature.

With warm engine: Between 75°C and 100°C (167°F and 212° F).

REPLACE ENGINE COOLANT TEMPERATURE SENSOR

CHECK PCV HOSE CONNECTIONS

(a) Check for PCV hose connections. OK:

PCV hose is connected correctly and is not damaged.

REPAIR OR REPLACE PCV HOSE

CHECK AIR INDUCTION SYSTEM

(a) Check the air induction system for vacuum leakage. OK:

No leakage from air induction system.

REPAIR OR REPLACE AIR INDUCTION SYSTEM

CHECK FOR SPARKS AND IGNITION (See page ES-171)

REPAIR OR REPLACE IGNITION SYSTEM

CHECK FOR EXHAUST GAS LEAK

(a) Check for exhaust gas leakage.

No gas leakage.

REPAIR OR REPLACE EXHAUST SYSTEM

CHECK FUEL PRESSURE

(a) Check the fuel pressure (see page FU-6). Standard pressure:

304 to 343 kPa (3.1 to 3.5 kgf/cm2, 44.1 to 49.7 psi)

REPAIR OR REPLACE FUEL SYSTEM

INSPECT FUEL INJECTOR (INJECTION AND VOLUME)

(a) Check the injection volume (see page FU-11). Standard injection volume: 45 to 58 cm3 (2.9 to 3.5 cu in.) per 15 seconds

REPLACE FUEL INJECTOR

11

INSPECT AIR-FUEL RATIO SENSOR (HEATER RESISTANCE) (See page ES-83)

NG

REPLACE AIR-FUEL RATIO SENSOR

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12

INSPECT INTEGRATION RELAY (EFI RELAY) (See page ES-84)

NG

REPLACE INTEGRATION RELAY

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13

CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM) (See page ES-310)

REPAIR OR REPLACE HARNESS OR CONNECTOR

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

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Responses

  • amanuel
    How to check dtc output or input?
    6 months ago

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