SFI SYSTEM, Diagnostic DTC:P2195, P2196, P2197, P2198

DTC Code	DTC Name
P2195	Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)
P2196	Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)
P2197	Oxygen (A/F) Sensor Signal Stuck Lean (Bank 2 Sensor 1)
P2198	Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2 Sensor 1)

DESCRIPTION

Tech Tips

Although the DTC titles say oxygen sensor, these DTCs relate to the Air-Fuel Ratio (A/F) sensor.
Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.

The A/F sensor generates a voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM with feedback so that it can control the air-fuel ratio. The ECM determines the deviation from the stoichiometric air-fuel ratio level, and regulates the fuel injection time. If the A/F sensor malfunctions, the ECM is unable to control the air-fuel ratio accurately.

The A/F sensor is the planar type and is integrated with the heater, which heats the solid electrolyte (zirconia element). This heater is controlled by the ECM. When the intake air volume is low (the exhaust gas temperature is low), a current flows into the heater to heat the sensor, in order to facilitate accurate oxygen concentration detection. In addition, the sensor and heater portions are narrower than the conventional type. The heat generated by the heater is conducted to the solid electrolyte through the alumina, and therefore the sensor activation is accelerated.

In order to obtain a high purification rate of the carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) components in the exhaust gas, a TWC is used. For the most efficient use of the TWC, the air-fuel ratio must be precisely controlled so that it is always close to the stoichiometric level.

*: Value changes inside the ECM. Since the A/F sensor is the current output element, a current is converted into a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.

DTC No.	DTC Detection Condition	Trouble Area
P2195 P2197	Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic) (a) Air-Fuel Ratio (A/F) sensor voltage more than 3.8 V (b) Heated Oxygen (HO2) sensor voltage increases from less than 0.21 V or more	Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) A/F sensor (bank 1, 2 sensor 1) heater A/F sensor heater Air induction system circuits Fuel pressure (low pressure side) Fuel pressure (high pressure side) Fuel injector for port injection Fuel injector for direct injection ECM
P2195 P2197	While fuel-cut operation performed (during vehicle deceleration), air-fuel ratio (A/F) sensor current 3.6 mA or more for 3 seconds (2 trip detection logic)	A/F sensor ECM
P2196 P2198	Conditions (a) and (b) continue for 5 seconds or more (2 trip detection logic) (a) A/F sensor voltage less than 2.8 V (b) HO2 sensor voltage falls from below 0.59 V	Open or short in A/F sensor (bank 1, 2 sensor 1) circuit A/F sensor (bank 1, 2 sensor 1) A/F sensor (bank 1, 2 sensor 1) heater A/F sensor heater circuits Air induction system Fuel pressure (low pressure side) Fuel pressure (high pressure side) Fuel injector for port injection Fuel injector for direct injection ECM
P2196 P2198	While fuel-cut operation performed (during vehicle deceleration), air-fuel ratio (A/F) sensor current less than 0.78 mA for 3 seconds (2 trip detection logic)	A/F sensor ECM

Tech Tips

DTCs P2195 and P2196 indicate malfunctions related to bank 1 A/F sensor circuit.
DTCs P2197 and P2198 indicate malfunctions related to bank 2 A/F sensor circuit.
Bank 1 refers to the bank that includes No. 1 cylinder.
Bank 2 refers to the bank that includes No. 2 cylinder.
When any of these DTCs are set, check the A/F sensor voltage output by entering the following menus: Powertrain / Engine / Data List / Gas A/F Control / AFS Voltage B1S1 or AFS Voltage B2S1.
Short-term fuel trim values can also be read using the intelligent tester.
The ECM regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a constant level. Therefore, the A/F sensor voltage output cannot be confirmed without using the intelligent tester.
If an A/F sensor malfunction is detected, the ECM sets a DTC.

MONITOR DESCRIPTION

Sensor voltage detection monitor

Under the air-fuel ratio feedback control, if the A/F sensor voltage output indicates rich or lean for a certain period of time, the ECM determines that there is a malfunction in the A/F sensor. The ECM illuminates the MIL and sets a DTC.

Example:

If the A/F sensor voltage output is less than 2.8 V (very rich condition) and HO2 sensor output voltage falls from 0.59 V or more to less than 0.21 V for 5 seconds, the ECM sets DTC P2196 or P2198. Alternatively, if the A/F sensor voltage output is more than 3.8 V (very lean condition) and HO2 sensor output voltage rises from less than 0.21 V to 0.59 V or more for 5 seconds, DTC P2195 or P2197 is set.

Sensor current detection monitor

A rich air-fuel mixture causes a low A/F sensor current, and a lean air-fuel mixture causes a high A/F sensor current. Therefore, the sensor output becomes low during acceleration, and it becomes high during deceleration with the throttle valve fully closed. The ECM monitors the A/F sensor current during fuel-cut and detects any abnormal current values.

If the A/F sensor output is 3.6 mA or more for more than 3 seconds of cumulative time, the ECM interprets this as a malfunction in the A/F sensor and sets DTC P2195 or P2197 (high-side stuck). If the A/F sensor output is less than 0.78 mA for more than 3 seconds of cumulative time, the ECM sets DTC P2196 or P2198 (low-side stuck).

WIRING DIAGRAM

CONFIRMATION DRIVING PATTERN

This confirmation driving pattern is used in the "PERFORM CONFIRMATION DRIVING PATTERN" procedure of the following diagnostic troubleshooting procedure.

(a) Connect the intelligent tester to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the tester ON.
(d) Clear DTCs Click here.
(e) Start the engine, and warm it up until the ECT reaches 75°C (167°F) or higher.
(f) Enter the following menus to check the fuel-cut status: Powertrain / Engine / Data List / All Data / Idle Fuel Cut.
(g) Drive the vehicle at between 38 mph (60 km/h) and 75 mph (120 km/h) for at least 10 minutes.
(h) Change the transmission to 2nd gear.
(i) Drive the vehicle at proper vehicle speed to perform fuel-cut operation (refer to the following HINT).
Tech Tips

Fuel-cut is performed when the following conditions are met:
- Accelerator pedal fully released.
- Engine speed is 2500 rpm or more (fuel injection returns at 1000 rpm).
(j) Accelerate the vehicle to 40 mph (64 km/h) or more by depressing the accelerator pedal for at least 10 seconds.
(k) Soon after performing step (j) above, release the accelerator pedal for at least 4 seconds without depressing the brake pedal, in order to execute fuel-cut control.
(l) Allow the vehicle to decelerate until the vehicle speed declines to less than 6 mph (10 km/h).
(m) Repeat steps from (h) through (k) above at least 3 times in one driving cycle.

Tech Tips

Completion of all O2S (A/F) Monitor is required to change the value in Data List.

CAUTION:

Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.

INSPECTION PROCEDURE

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
A low A/F sensor voltage could be caused by a rich air-fuel mixture. Check for conditions that would cause the engine to run rich.
A high A/F sensor voltage could be caused by a lean air-fuel mixture. Check for conditions that would cause the engine to run lean.
Bank 1 refers to the bank that includes the No. 1 cylinder*.

*: The No. 1 cylinder is the cylinder which is farthest from the transmission.
Bank 2 refers to the bank that does not include the No. 1 cylinder.
Sensor 1 refers to the sensor closest to the engine assembly.
Sensor 2 refers to the sensor farthest away from the engine assembly.

PROCEDURE

CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, P2197 OR P2198)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester ON.
Enter the following menus: Powertrain / Engine / DTC.

Read the DTCs.

Result

Display (DTC Output)	Proceed to
P2195, P2196, P2197 or P2198 is output	A
"P2195, P2196, P2197 or P2198" and "P0136, P0137, P0138, P0156, P0157 or P0158" are output	A
P2195, P2196, P2197 or P2198 and other DTCs are output	B

Tech Tips

If any DTCs other than P2195, P2196, P2197 or P2198 are output, troubleshoot those DTCs first.

GO TO DTC CHART Click here

READ VALUE USING INTELLIGENT TESTER (TEST VALUE OF A/F SENSOR)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester ON.
Clear DTCs Click here.
Drive the vehicle in accordance with the drive pattern described in the CONFIRMATION DRIVING PATTERN.
Enter the following menus: Powertrain / Engine / Data List / Monitor Status.
Check that the status of O2S (A/FS) Monitor is Complete.

If the status is still Incomplete, drive the vehicle according to the driving pattern again.
Tech Tips
- Complete indicates that the component is functioning normally.
- Incomplete indicates that the component is malfunctioning.
Enter the following menus: Powertrain / Engine / Data List / Gas A/F Control / AFS Current B1S1 or AFS Current B2S1.

Check the test value of the A/F sensor output current during fuel-cut.

Result

Test Value	Proceed to
Within normal range (0.78 mA or more, and less than 3.6 mA)	A
Outside normal range (Less than 0.78 mA, or 3.6 mA or more)	B

REPLACE AIR FUEL RATIO SENSOR Click here

READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF A/F SENSOR)

Connect the intelligent tester to the DLC3.
Start the engine.
Turn the tester ON.
Warm up the Air-Fuel Ratio (A/F) sensor at an engine speed of 2500 rpm for 90 seconds.
Enter the following menus: Powertrain / Engine / Data List / A/F Control System / Snapshot / AFS Voltage B1S1 or AFS Voltage B1S1 and Engine Speed.

Check the A/F sensor voltage three times, when the engine is in each of the following conditions:

While idling (check for at least 30 seconds)
At an engine speed of approximately 2500 rpm (without any sudden changes in engine speed)

Raise the engine speed to 4000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.

Standard

Condition

A/F Sensor Voltage Variation

Reference

(1) and (2)

Changes at approximately 3.3 V

Between 3.1 V and 3.5 V

(3)

Increases to 3.8 V or more

This occurs during engine deceleration

(when fuel-cut performed)

Tech Tips

For more information, see the diagrams below.

Tech Tips

If the output voltage of the A/F sensor remains at approximately 3.3 V (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have an open circuit. (This will also happen if the A/F sensor heater has an open circuit.)
If the output voltage of the A/F sensor remains at either approximately 3.8 V or more, or 2.8 V or less (see Malfunction Condition diagram) under any conditions, including those above, the A/F sensor may have a short circuit.
The ECM stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and results in a momentary increase in the A/F sensor output voltage.
The ECM must establish a closed throttle valve position learning value to perform fuel cut. If the battery terminal has been reconnected, the vehicle must be driven over 10 mph (16 km/h) to allow the ECM to learn the closed throttle valve position.
When the vehicle is driven:

The output voltage of the A/F sensor may be below 2.8 V during fuel enrichment. For the vehicle, this translates to a sudden increase in speed with the accelerator pedal fully depressed when trying to overtake another vehicle. The A/F sensor is functioning normally.
The A/F sensor is a current output element; therefore, the current is converted into a voltage inside the ECM. Measuring the voltage at the connectors of the A/F sensor or ECM will show a constant voltage result.

Click here

PERFORM CONFIRMATION DRIVING PATTERN

NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and the tester ON.
Enter the following menus: Powertrain / Engine / DTC / Pending.

Read DTCs.

Result

Display (DTC Output)	Proceed to
P2195, P2196, P2197 or P2198	A
No output	B

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST Click here

REPLACE AIR FUEL RATIO SENSOR
1. Replace the air fuel ratio sensor .
  Tech Tips
  - for 2WD Click here.
  - for AWD Click here.
NEXT
PERFORM CONFIRMATION DRIVING PATTERN

NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and the tester ON.
Enter the following menus: Powertrain / Engine / DTC / Pending.

Read DTCs.

Result

Display (DTC Output)	Proceed to
No output	A
P2195, P2196, P2197 or P2198	B

REPLACE ECM AND PERFORM CONFIRMATION DRIVING PATTERN

END

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

NO
CHECK FOR INTERMITTENT PROBLEMS Click here

YES

DTC CAUSED BY RUNNING OUT OF FUEL

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

Disconnect the E47*1 or E48*2 A/F sensor connector.

Tech Tips

*1: Bank 1 Sensor 1

*2: Bank 2 Sensor 1

Measure the resistance according to the value(s) in the table below.

Standard resistance (Bank 1 Sensor 1)

Tester Connection	Condition	Specified Condition
1 (HA1A) - 2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
1 (HA1A) - 4 (A1A-)	Always	10 kΩ or higher

Standard resistance (Bank 2 Sensor 1)

Tester Connection	Condition	Specified Condition
1 (HA2A) - 2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
1 (HA2A) - 4 (A2A-)	Always	10 kΩ or higher

Result
Result	Proceed to
OK	A
NG (for 2WD)	B
NG (for AWD)	C

REPLACE AIR FUEL RATIO SENSOR Click here

CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)

Disconnect the E47 and E48 A/F sensor connectors.
Turn the engine switch on (IG).

Measure the voltage according to the value(s) in the table below.

Standard voltage

Tester Connection	Switch Condition	Specified Condition
E47-2 (+B) - Body ground	Engine switch on (IG)	11 to 14 V
E48-2 (+B) - Body ground	Engine switch on (IG)	11 to 14 V

Turn the engine switch off.
Disconnect the E3 and E4 ECM connectors.

Measure the resistance according to the value(s) in the table below.

Standard resistance (Check for open)

Tester Connection	Condition	Specified Condition
E47-1 (HA1A) - E3-5 (HA1A)	Always	Below 1 Ω
E47-3 (A1A+) - E4-23 (A1A+)	Always	Below 1 Ω
E47-4 (A1A-) - E4-22 (A1A-)	Always	Below 1 Ω
E48-1 (HA2A) - E3-6 (HA2A)	Always	Below 1 Ω
E48-3 (A2A+) - E4-21 (A2A+)	Always	Below 1 Ω
E48-4 (A2A-) - E4-20 (A2A-)	Always	Below 1 Ω

Standard resistance (Check for short)

Tester Connection	Condition	Specified Condition
E47-1 (HA1A) or E3-5 (HA1A) - Body ground	Always	10 kΩ or higher
E47-3 (A1A+) or E4-23 (A1A+) - Body ground	Always	10 kΩ or higher
E47-4 (A1A-) or E4-22 (A1A-) - Body ground	Always	10 kΩ or higher
E48-1 (HA2A) or E3-6 (HA2A) - Body ground	Always	10 kΩ or higher
E48-3 (A2A+) or E4-21 (A2A+) - Body ground	Always	10 kΩ or higher
E48-4 (A2A-) or E4-20 (A2A-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

CHECK AIR INDUCTION SYSTEM
1. Check the air induction system for vacuum leakage.
  
  OK
  
  No leakage from air induction system.
NG
REPAIR OR REPLACE AIR INDUCTION SYSTEM

OK
CHECK FUEL PRESSURE
1. Check the fuel pressure Click here.
NG
REPAIR OR REPLACE FUEL SYSTEM (LOW PRESSURE SIDE)

OK
INSPECT FUEL INJECTOR FOR PORT INJECTION
1. Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor) Click here.
NG
REPLACE FUEL INJECTOR FOR PORT INJECTION Click here

OK

OK
No leakage from air induction system.

READ VALUE USING INTELLIGENT TESTER (FUEL PRESS)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester ON.
Start the engine.
Enter the following menus: Powertrain / Engine / Data List / All Data / Fuel Press.

While revving the engine, check that the fuel pressure fluctuates.

Standard
Idling
3000 to 5000 kPa
2000 rpm (No load)
7000 to 9000 kPa

Tech Tips

The A/C switch and all accessory switches should be OFF, the transmission gear selector lever should be in the N or P position, and the engine should be fully warmed up.

REPAIR OR REPLACE FUEL SYSTEM (HIGH PRESSURE SIDE)

INSPECT FUEL INJECTOR FOR DIRECT INJECTION
1. Inspect the fuel injector for direct injection Click here.
NG
REPLACE FUEL INJECTOR FOR DIRECT INJECTION Click here

OK
REPLACE AIR FUEL RATIO SENSOR
1. Replace the air fuel ratio sensor.
  Tech Tips
  - for 2WD Click here.
  - for AWD Click here.
NEXT
PERFORM CONFIRMATION DRIVING PATTERN

NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and the tester ON.
Enter the following menus: Powertrain / Engine / DTC / Pending.

Read DTCs.

Result

Display (DTC Output)	Proceed to
No output	A
P2195, P2196, P2197 or P2198	B

REPLACE ECM AND PERFORM CONFIRMATION DRIVING PATTERN

CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST

NO
CHECK FOR INTERMITTENT PROBLEMS Click here

YES

DTC CAUSED BY RUNNING OUT OF FUEL
REPLACE AIR FUEL RATIO SENSOR
1. Replace the air fuel ratio sensor.
  Tech Tips
  - for 2WD Click here.
  - for AWD Click here.
NEXT
PERFORM CONFIRMATION DRIVING PATTERN

NEXT

CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)

Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG) and turn the tester ON.
Enter the following menus: Powertrain / Engine / DTC / Pending.

Read DTCs.

Result

Display (DTC Output)	Proceed to
No output	A
P2195, P2196, P2197 or P2198 (A/F sensor pending DTCs)	B

REPLACE ECM Click here

END