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DTC P2096 POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1

DTC P2096 POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1

DTC DETECTING CONDITION:


• Two consecutive driving cycles with fault

• GENERAL DESCRIPTION

Important

After repair or replacement of faulty parts, conduct Clear Memory Mode and Inspection Mode .



WIRING DIAGRAM:


CHECK ANY OTHER DTC ON DISPLAY.

Is any other DTC displayed?

Yes

Using the List of Diagnostic Trouble Code (DTC), check the appropriate DTC.


No


CHECK REAR OXYGEN SENSOR DATA.

Warm-up the engine until engine coolant temperature is above 70°C (158°F), and keep the engine speed at 2,000 rpm to 3,000 rpm for 2 minutes.

Read the data of rear oxygen sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA SHOWN ON DISPLAY FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.


Does the value fluctuate?

Yes


No


CHECK REAR OXYGEN SENSOR DATA.

Read the data of rear oxygen sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Is the voltage 0.2 — 0.4 V?

Yes


No

• Replace the rear oxygen sensor.


CHECK HARNESS BETWEEN ECM AND REAR OXYGEN SENSOR CONNECTOR.

Turn the ignition switch to OFF.

Disconnect the connectors from ECM and rear oxygen sensor.

Measure the resistance of harness between ECM and rear oxygen sensor connector.

Connector & terminal

(B135) No. 17 — (B19) No. 3:

Is the resistance more than 3 Ω?

Yes

Repair the open circuit in harness between ECM and rear oxygen sensor connector.


No


CHECK HARNESS BETWEEN REAR OXYGEN SENSOR AND ECM CONNECTOR.

Turn the ignition switch to OFF.

Disconnect the connector from rear oxygen sensor.

Turn the ignition switch to ON.

Measure the voltage between rear oxygen sensor harness connector and engine ground or chassis ground.

Connector & terminal

(B19) No. 3 (+) — Engine ground (−):

Is the voltage more than 0.2 V?

Yes

Replace the rear oxygen sensor.


No

• Repair the harness and connector.

•
Note

In this case, repair the following:

• Open circuit in harness between rear oxygen sensor and ECM connector

• Poor contact in rear oxygen sensor connector

• Poor contact in ECM connector



CHECK EXHAUST SYSTEM.

Check the exhaust system parts.

Note

Check the following items.

• Loose installation of portions

• Damage (crack, hole etc.) of parts

• Looseness and ill fitting of parts between front oxygen (A/F) sensor and rear oxygen sensor


Is there a fault in exhaust system?

Yes

Repair or replace the faulty parts.


No


CHECK AIR INTAKE SYSTEM.

Are there holes, loose bolts or disconnection of hose on air intake system?

Yes

Repair the air intake system.


No


CHECK FUEL PRESSURE.

Warning
• Place “NO FIRE” signs near the working area.

• Be careful not to spill fuel on the floor.


Release the fuel pressure.

Connect the connector to fuel pump relay.

Disconnect the fuel delivery hose from fuel filter, and connect fuel pressure gauge.

Install the fuel filler cap.

Start the engine and idle while gear position is neutral.

Measure the fuel pressure while disconnecting pressure regulator vacuum hose from intake manifold.

Warning

Before removing the fuel pressure gauge, release fuel pressure.


Note

If the fuel pressure does not increase, squeeze fuel return hose 2 to 3 times, then measure fuel pressure again.


Is the measured value 284 — 314 kPa (2.9 — 3.2 kg/cm 2 , 41 — 46 psi)?

Yes


No

• Repair the following items.

• Fuel pressure too high:

• Clogged fuel return line or bent hose

• Fuel pressure too low:

• Improper fuel pump discharge

• Clogged fuel supply line


CHECK FUEL PRESSURE.

After connecting the pressure regulator vacuum hose, measure fuel pressure.

Warning

Before removing the fuel pressure gauge, release fuel pressure.


Note
• If the fuel pressure does not increase, squeeze fuel return hose 2 to 3 times, then measure fuel pressure again.

• If out of specification as measured at this step, check or replace the pressure regulator and pressure regulator vacuum hose.


Is the measured value 206 — 235 kPa (2.1 — 2.4 kg/cm 2 , 30 — 34 psi)?

Yes


No

• Repair the following items.

• Fuel pressure too high:

• Faulty pressure regulator

• Clogged fuel return line or bent hose

• Fuel pressure too low:

• Faulty pressure regulator

• Improper fuel pump discharge

• Clogged fuel supply line


CHECK ENGINE COOLANT TEMPERATURE SENSOR.

Start the engine and warm-up completely.

Read the data of engine coolant temperature sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedures, refer to the OBD-II General Scan Tool Instruction Manual.


Is the temperature more than 60°C (140°F)?

Yes


No

Replace the engine coolant temperature sensor.


CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE.

Start the engine and warm-up engine until coolant temperature is greater than 60°C (140°F).

Place the shift lever in neutral position.

Turn the A/C switch to OFF.

Turn all accessory switches to OFF.

Read the data of mass air flow and intake air temperature sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedure, refer to the OBD-II General Scan Tool Instruction Manual.


Is the measured value within the followings? Ignition ON: 73.3 — 106.6 kPa (550 — 800 mmHg, 21.65 — 31.50 inHg) Idling: 24.0 — 41.3 kPa (180 — 310 mmHg, 7.09 — 12.20 inHg)

Yes


No

Replace the mass air flow and intake air temperature sensor.


CHECK MASS AIR FLOW AND INTAKE AIR TEMPERATURE SENSOR.

Start the engine and warm-up engine until coolant temperature is greater than 60°C (140°F).

Place the shift lever in neutral position.

Turn the A/C switch to OFF.

Turn all accessory switches to OFF.

Open the front hood.

Measure the ambient temperature.

Read the data of mass air flow and intake air temperature sensor signal using Vehicle Diagnostic Interface or OBD-II general scan tool.

Note
• Vehicle Diagnostic Interface

For detailed operation procedure, refer to the “READ CURRENT DATA FOR ENGINE”.

• OBD-II general scan tool

For detailed operation procedure, refer to the OBD-II General Scan Tool Instruction Manual.


Subtract ambient temperature from intake air temperature. Is the obtained value −10°C — 50°C (14°F — 122°F)?

Yes

Contact Service Center.


No

Check the mass air flow and intake air temperature sensor.