P2198

3MZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P2195: Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)

DTC P2195 - Oxygen (A/F) Sensor Signal Stuck Lean (Bank 1 Sensor 1)

DTC P2196 - Oxygen (A/F) Sensor Signal Stuck Rich (Bank 1 Sensor 1)

DTC P2197 - Oxygen (A/F) Sensor Signal Stuck Lean (Bank 2 Sensor 1)

DTC P2198 - Oxygen (A/F) Sensor Signal Stuck Rich (Bank 2 Sensor 1)

DESCRIPTION
HINT:
- 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 voltage* that corresponds to the actual air-fuel ratio. This sensor voltage is used to provide the ECM (Included in HV control ECU) 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, therefore the sensor activation is accelerated.
A three-way catalytic converter (TWC) is used in order to convert the carbon monoxide (CO), hydrocarbon (HC), and nitrogen oxides (NOx) into less harmful substances. To allow the TWC to function effectively, it is necessary to keep the air-fuel ratio of the engine near the stoichiometric air-fuel ratio.
*: Value changes inside the ECM. Since the A/F sensor is the current output element, a current is converted to a voltage inside the ECM. Any measurements taken at the A/F sensor or ECM connectors will show a constant voltage.









HINT:
- DTCs P2195 and P2196 indicate malfunctions related to the bank 1 A/F sensor circuit.
- DTCs P2197 and P2198 indicate malfunctions related to the bank 2 A/F sensor circuit.
- Bank 1 refers to the bank that includes cylinder No. 1.
- Bank 2 refers to the bank that includes cylinder No. 2.
- When any of these DTCs are set, check the A/F sensor output voltage by entering the following menus on Techstream: Powertrain / Engine and ECT / Data List / A/F Control System / AFS B1 S1 or AFS B2 S1.
- Short-term fuel trim values can also be read using Techstream.
- The ECM (Included in HV control ECU) regulates the voltages at the A1A+, A2A+, A1A- and A2A- terminals of the ECM to a constant level. Therefore, the A/F sensor output voltage cannot be confirmed without using Techstream.
- If a A/F sensor malfunction is detected, the ECM sets a DTC.

MONITOR DESCRIPTION

Under the air-fuel ratio feedback control, if the A/F sensor output voltage indicates rich or lean for a certain period of time, the ECM (Included in HV control ECU) 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) for 10 seconds, despite the HO2 sensor output voltage being less than 0.85 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 10 seconds, despite the HO2 sensor output voltage being 0.15 V or more, DTC P2195 is set.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





Sensor voltage detection monitor (Lean side malfunction P2195, P2197):





Sensor voltage detection monitor (Rich side malfunction P2196, P2198):





Sensor current detection monitor P2195, P2196, P2197 and P2198





TYPICAL MALFUNCTION THRESHOLDS

Sensor voltage detection monitor (Lean side malfunction P2195, P2197):





Sensor voltage detection monitor (Rich side malfunction P2196, P2198):





Sensor current detection monitor (High side malfunction P2195 and P2197):





Sensor current detection monitor (Low side malfunction P2196 and P2198):





MONITOR RESULT

Refer to CHECKING MONITOR STATUS Mode 6 Data.
The test value and test limit information are described as shown in the following table. Check the monitor result and test values after performing the monitor drive pattern (refer to "Confirmation Monitor").

- MID (Monitor Identification Date) is assigned to each emission-related component.
- TID (Test Identification Date) is assigned to each emission-related component.
- Scaling is used to calculate the test value indicated on generic OBD II scan tools.

Bank 1 Sensor 1





Bank 2 Sensor 1





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 Techstream to the DLC3 (a).
- (b) Turn the power switch on (IG) (b).
- (c) Turn the tester on (c).
- (d) Clear the DTCs Check Mode Procedure (d).
- (e) Put the engine in inspection mode Inspection Mode Procedure, warm it up until the ECT reaches 75°C (167°F) or higher (e).
- (f) On Techstream, select the following menu items to check the fuel-cut status: Powertrain / Engine and ECT / Data List / Idle Fuel Cut (f).
- (g) Drive the vehicle at between 47 mph (75 km/h) and 75 mph (120 km/h) for at least 10 minutes (g).
- (h) Drive the vehicle at a proper vehicle speed to perform fuel-cut operation (h).
HINT: Fuel-cut is performed when the following conditions are met:
- Accelerator pedal is fully released.
- Vehicle speed is 44 mph (70 km/h) or more (fuel injection resumes at 44 mph (70 km/h).
- (i) Accelerate the vehicle to 56 mph (90 km/h) or more by depressing the accelerator pedal for at least 5 minutes or more (i).
- (j) Soon after performing step (i) above, release the accelerator pedal for at least 6 seconds without depressing the brake pedal, in order to execute fuel-cut control (j).
- (k) Allow the vehicle to decelerate until the vehicle speed declines to less than 44 mph (70 km/h) (k).
- (l) Repeat steps from (h) through (j) above at least 3 times in one driving cycle (l).
HINT: Completion of all A/F sensor monitors is required to change the value in TEST RESULT.
CAUTION: Strictly observe posted speed limits, traffic laws, and road conditions when performing these drive patterns.

INSPECTION PROCEDURE
HINT: Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the Air-fuel Ratio (A/F) sensor, Heated Oxygen (HO2) sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using Techstream.
1 Connect Techstream to the DLC3.
2 Put the engine in inspection mode Inspection Mode Procedure.
3 Start the engine and turn the tester ON.
4 Warm up the engine at an engine speed of 2,500 rpm for approximately 90 seconds.
5 On the Techstream, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
6 Perform the Control the Injection Volume for A/F Sensor operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume).
7 Monitor the output voltages of the A/F and HO2 sensors (AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2) displayed on the tester.
HINT:
- The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
- Each sensor reacts in accordance with increases in the fuel injection volume.

Standard:





NOTE: The Air-Fuel Ratio (A/F) sensor has an output delay of a few seconds and the HO2S (sensor 2) output has a maximum of 20 seconds of delay.





- Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the A/F and HO2 sensors.
- To display the graph, enter the following menus on the tester: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AFS B1 S1 or AFS B2 S1 and O2S B1 S2 or O2S B2 S2 then press the graph button on the Data List view.
HINT:
- Read freeze frame data using Techstream. The ECM (Included in HV control ECU) records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, 2197 OR P2198)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Turn the tester ON.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Code.
(e) Read the DTCs.
Result:





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

B -- GO TO DTC CHART
A -- Continue to next step.
2. READ VALUE OF TECHSTREAM (OUTPUT VOLTAGE OF A/F SENSOR)
(a) Connect Techstream to the DLC3.
(b) Put the engine in inspection mode Inspection Mode Procedure.
(c) Start the engine.
(d) Turn the tester ON.
(e) Warm up the Air-Fuel Ratio (A/F) sensor at an engine speed of 2,500 rpm for 90 seconds.
(f) On the tester, enter the following menus: Powertrain / Engine an ECT / Data List / AFS B1 S1 and Engine Speed.
(g) Check the A/F sensor voltage three times, when the engine is in each of the following conditions:
(1) While idling (check for at least 30 seconds)
(2) At an engine speed of approximately 2,500 rpm (without any sudden changes in engine speed)
(3) Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.
Standard voltage:





HINT:
- For more information, see the diagrams below.





- 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 (Included in HV control ECU) 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. The vehicle translates this as 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.

NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- Continue to next step.
3. INSPECT AIR FUEL RATIO SENSOR





(a) Disconnect the A3 or A4 A/F sensor connector.
(b) Measure the resistance between the terminals of the A/F sensor connector.
Standard resistance:





(c) Reconnect the A/F sensor connector.
NG -- REPLACE AIR FUEL RATIO SENSOR
OK -- Continue to next step.
4. INSPECT A/F RELAY





(a) Remove the A/F relay from the engine room R/B.
(b) Measure the A/F relay resistance.
Standard resistance:





(c) Reinstall the A/F relay.
NG -- REPLACE A/F RELAY
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (A/F SENSOR - HV CONTROL ECU)





(a) Disconnect the A3 and A4 A/F sensor connectors.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage between the +B terminal of the A/F sensor connector and body ground.
Standard voltage:





(d) Turn the ignition switch off.
(e) Disconnect the H33 HV control ECU connector.
(f) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):






Standard resistance (Check for short):





(g) Reconnect the HV control ECU connector.
(h) Reconnect the A/F sensor connector.





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK AIR INDUCTION SYSTEM
(a) Check the air induction system for vacuum leakage.
OK:
No leakage from air induction system.
NG -- REPAIR OR REPLACE AIR INDUCTION SYSTEM
OK -- Continue to next step.
7. CHECK FUEL PRESSURE
(a) Check the fuel pressure Testing and Inspection.
Standard:
304 to 343 kPa (3.1 to 3.5 kgf/cm2, 44.1 to 49.7 psi)
NG -- REPAIR OR REPLACE FUEL SYSTEM
OK -- Continue to next step.
8. INSPECT FUEL INJECTOR ASSEMBLY
(a) Check the injector injection Testing and Inspection.
OK:
13 cm3 (0.8 cu in.) or less
NG -- REPLACE FUEL INJECTOR ASSEMBLY
OK -- Continue to next step.
9. REPLACE AIR FUEL RATIO SENSOR
NEXT -- Continue to next step.
10. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
11. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Read the DTCs using Techstream.
(b) Enter the following menus: Powertrain / Engine and ECT / Trouble Code / Pending.
Result:






B -- REPLACE HV CONTROL ECU
A -- Continue to next step.
12. CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
NO -- CHECK FOR INTERMITTENT PROBLEMS
YES -- DTC CAUSED BY RUNNING OUT OF FUEL
13. REPLACE AIR FUEL RATIO SENSOR
NEXT -- Continue to next step.
14. PERFORM CONFIRMATION DRIVING PATTERN
NEXT -- Continue to next step.
15. CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the ON position and turn the tester ON.
(c) Read the DTCs using Techstream.
(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Code / Pending.
Result:






B -- REPLACE HV CONTROL ECU
A -- END