Result

Status AFS B1S1

Status O2S B1S2

A/F Condition and A/F Sensor Condition

Misfires

Suspected Trouble Areas

Proceed To

Lean/Rich

Lean/Rich

Normal

-

-

C

Lean

Lean

Actual air-fuel ratio lean

• PCV hose connections

• Injector blockage

• Gas leakage from exhaust system

• Air induction system

• Fuel pressure

• Engine Coolant Temperature(ECT) sensor

A

Rich

Rich

Actual air-fuel ratio rich

-

• Injector leakage or blockage

• Gas leakage from exhaust system

• Ignition system

• Fuel pressure

• ECT sensor

A

Lean

Lean/Rich

A/F sensor malfunction

-

• A/F sensor

B

Rich

Lean/Rich

A/F sensor malfunction

-

• A/F sensor

B

Lean: During A/F CONTROL, the A/F sensor output voltage (AFS) is consistently more than 3.35 V, and the HO2 sensor output voltage (O2S) is consistently less than 0.4 V. Rich: During A/F CONTROL, the AFS is consistently less than 3.0 V, and the O2S is consistently more than 0.5 V. Lean/Rich: During A/F CONTROL of the ACTIVE TEST, the output voltage of the heated oxygen sensor alternates correctly.

Go to step 11

Go to step 15

READ DATA LIST (COOLANT TEMP)

Connect the intelligent tester to the DLC3. Turn the ignition switch to ON and turn the tester ON. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / COOLANT TEMP.

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 95°C (167°F and 203°F)

REPLACE ENGINE COOLANT TEMPERATURE SENSOR

READ DATA LIST (MAF)

Connect the intelligent tester to the DLC3. Turn the ignition switch to ON and turn the tester ON. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / MAF and COOLANT TEMP.

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

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 2.0 g/sec and 4.5 g/sec (shift position: N, A/C: OFF). MAF at engine speed of 2,500 rpm: Between 8.0 g/ sec and 14.7 g/sec (shift position: N, A/C: OFF).

REPLACE MASS AIR FLOW METER

CHECK FUEL PRESSURE

(a) Check the fuel pressure.

REPAIR OR REPLACE FUEL SYSTEM

CHECK FOR EXHAUST GAS LEAKAGE

No gas leakage.

REPAIR OR REPLACE EXHAUST SYSTEM

CHECK FOR SPARK AND IGNITION

HINT:

If the spark plugs or ignition system malfunctions, engine misfire may occur. The misfire count can be read using an intelligent tester. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL #1 (to CYL #4).

REPAIR OR REPLACE IGNITION SYSTEM

INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

HINT:

If the injectors malfunction, engine misfire may occur. The misfire count can be read using an intelligent tester. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / MISFIRE / CYL #1 (to CYL #4).

REPLACE FUEL INJECTOR ASSEMBLY

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