Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fse Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, 2197 OR P2198)
READ VALUE USING INTELLIGENT TESTER (OUTPUT VOLTAGE OF A/F SENSOR)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)
CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM)
INSPECT FUEL INJECTOR ASSEMBLY
PERFORM CONFIRMATION DRIVING PATTERN
CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198)
CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST
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 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 though the alumina, 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 to 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 2 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 0.15 V or more |
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| 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) |
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| P2196 P2198 | Conditions (a) and (b) continue for 2 seconds or more (2 trip detection logic): (a) A/F sensor voltage less than 2.8 V (b) HO2 sensor voltage less than 0.85 V |
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| P2196 P2198 | While fuel-cut operation performed (during vehicle deceleration), air-fuel ratio (A/F) sensor current 1.4 mA for 3 seconds (2 trip detection logic) |
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- HINT:
- 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 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 the intelligent tester: Power train / Engine / Data List / AFS B1 S1 or AES B2 S1.
- Short-term fuel trim values can also be read using an 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 output voltage cannot be confirmed without using the intelligent tester.
- If a A/F sensor malfunction is detected, the ECM sets a DTC.
MONITOR DESCRIPTION
Sensor voltage detection monitorUnder 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 determines that is a malfunction in the A/F sensor. The ECM illuminates thee 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 0.6 V, the ECM sets DTC P2196. Alternatively, if the A/F sensor output voltage is more than 3.8 V (very lean condition) for 15 seconds, despite the HO2 sensor output voltage being 0.15 V or more, DTC P2195 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 (high-side stuck). If the A/F sensor output is 1.0 mA or less for more than 3 seconds of cumulative time, the ECM sets DTC P2196 (low-side stuck).
WIRING DIAGRAM
CONFIRMATION DRIVING PATTERN
This confirmation driving pattern is used in steps 2, 4, 7, 17 and 21 of the following diagnostic troubleshooting procedure when using an intelligent tester.
- (a) Connect an intelligent tester to the DLC3.
- (b) Turn the engine switch on (IG).
- (c) Turn the tester ON.
- (d) Clear DTCs.
- (e) Start the engine, and warm it up until the ECT reaches 70°C (158°F) or higher.
- (f) On the intelligent tester, enter the following menus to check the fuel-cut status: Power train / Engine / Data List / Idle Fuel Cut
- (g) Drive the vehicle at between 60 km/h (38 mph) and 120 km/h (75 mph) 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).
- HINT:
- Fuel-cut is performed when the following conditions are met:
- Accelerator pedal fully released.
- Engine speed is 2,500 rpm or more (fuel injection returns at 1,000 rpm).
- (j) Accelerate the vehicle to 64 km/h (40 rpm) 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 10 km/h (6 mph).
- (m) Repeat steps from (h) through (k) above at least 3 times in one driving cycle.
- 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.
- 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 intelligent tester, enter the following menus: Power train / Engine / Active Test / Control the Injection Volume for A/F Sensor.
- 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).
- Monitor the output voltages of the A/F and HO2 sensors (AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2) 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 24.8 %.
- Each sensor reacts in accordance with increases in the fuel injection volume.
| Tester Display (Sensor) | Injection Volume | Status | Voltage |
| AFS B1 S1 or AFS B2 S1 (A/F) | +24.8 % | Rich | Less than 3.0 |
| AFS B1 S1 or AFS B2 S1 (A/F) | -12.5 % | Lean | More than 3.35 |
| O2S B1 S2 or O2S B2 S2 (HO2) | +24.8 % | Rich | More than 0.55 |
| O2S B1 S2 or O2S B2 S2 (HO2) | -12.5 % | Lean | Less than 0.4 |
- NOTICE:
- 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.
| Case | A/F Sensor (Sensor 1) Output Voltage | HO2 Sensor (Sensor 2) Output Voltage | Main Suspected Trouble Areas | ||
| 1 | Injection Volume +25 % -12.5 % |  | Injection Volume +25 % -12.5 % | | - |
| Output Voltage More than 3.35 V Less than 3.0 V |  | Output Voltage More than 0.55 V Less than 0.4 V |  | ||
| 2 | Injection Volume +25 % -12.5 % | | Injection Volume +25 % -12.5 % | |
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| Output Voltage Almost no reaction |  | Output Voltage More than 0.55 V Less than 0.4 V | | ||
| 3 | Injection Volume +25 % -12.5 % | | Injection Volume +25 % -12.5 % | |
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| Output Voltage More than 3.35 V Less than 3.0 V | | Output Voltage Almost no reaction | | ||
| 4 | Injection volume +25 % -12.5 % | | Injection Volume +25 % -12.5 % | |
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| Output Voltage Almost no reaction | | Output Voltage Almost no reaction | | ||
- 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: Power train / Engine / Active Test / Control the Injection Volume for A/F Sensor and Data List / AFS B1 S1 and O2S B1 S2 or AFS B2 S1 and O2S B2 S2.
- HINT:
- Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. 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.
| 1.CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO P2195, P2196, 2197 OR P2198) |
Connect the intelligent tester to the DLC3.
Turn the engine switch on (IG).
Turn the tester ON
Enter the following menus: Power train / Engine / DTC.
Read DTCs.
Result: Display (DTC Output) Proceed to P2195, P2196, P2197, or P2198 A P2195, P2196, P2197, or P2198 and other DTCs B
- HINT:
- If any DTCs other than P2195, P2196, P2197 or P2198 are output, troubleshoot those DTCs first.
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| A | |
| 2.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 2,500 rpm for 90 seconds.
On the tester, enter the following menus: Power train / Engine / Data List / AFS B1 S1 or AFS B2 S1 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 2,500 rpm (without any sudden changes in engine speed)
Raise the engine speed to 4,000 rpm and then quickly release the accelerator pedal so that the throttle valve is fully closed.
| 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) |
- 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 stops fuel injection (fuel cut) during engine deceleration. This causes a lean condition and result 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 16 km/h (10 mph) to allow the ECM terminal has been reconnected, the vehicle must be driven over 16 km/h (10 mph) 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.
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| OK | |
| 3.PERFORM CONFIRMATION DRIVING PATTERN |
| NEXT | |
| 4.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198) |
Read DTCs using the intelligent tester.
Enter the following menus: Power train / Engine / DTC.
Result: Display (DTC Output) Proceed to P2195, P2196, P2197, or P2198 A No output B
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| A | |
| 5.REPLACE AIR FUEL RATIO SENSOR |
| NEXT | |
| 6.PERFORM CONFIRMATION DRIVING PATTERN |
| NEXT | |
| 7.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198) |
Read DTCs using the intelligent tester.
Enter the following menus: Power train / Engine / DTC.
Result: Display (DTC Output) Proceed to No output A P2195, P2196, P2197, or P2198 B
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| A | |
| 8.CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST |
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| YES | ||
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| 9.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE) |
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Disconnect the E68 or E65 A/F sensor connector.
Measure the resistance of the terminals of the A/F sensor connector.
- Standard resistance (Bank 1 sensor 1):
Tester Connection Specified Condition HA1A (1) - +B (2) 1.8 Ω to 3.4 Ω at 20°C (68°F) HA1A (1) - A1A- (4) 10 kΩ or higher
- Standard resistance (Bank 2 sensor 1):
Tester Connection Specified Condition HA2A (1) - +B (2) 1.8 Ω to 3.4 Ω at 20°C (68°F) HA2A (1) - A1A- (4) 10 kΩ or higher
Reconnect the A/F sensor connector.
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| OK | |
| 10.INSPECT A/F HTR RELAY |
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Remove the A/F HTR relay from the engine room No. 2 relay block.
Measure the resistance of the A/F HTR relay .
- Standard resistance:
Tester Connection Specified Condition 3 - 5 10 kΩ or higher 3 - 5 Below 1 Ω
(when battery voltage applied to terminals 1 and 2)
Reinstall the A/F HTR relay.
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| OK | |
| 11.CHECK HARNESS AND CONNECTOR (A/F SENSOR - ECM) |
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Disconnect the E68 and E65 A/F sensor connector.
Turn the engine switch on (IG).
Measure the voltage between the +B terminal of the A/F sensor connector and body ground.
- Standard voltage:
Tester Connection Specified Condition +B (E68-2) - Body ground 9 to 14 V +B (E65-2) - Body ground 9 to 14 V
Turn the engine switch off.
Disconnect the E45 ECM connector.
Measure the resistance.
- Standard resistance (Check for open):
Tester Connection Specified Condition HA1A( E68-1) - HA1A (E45-6) Below 1 Ω A1A+ (E68-3) - A1A+ (E45-18) Below 1 Ω A1A- (E68-4) - A1A- (E5-17) Below 1 Ω HA2A (E65-1) - HA2A (E45-4) Below 1 Ω A2A+ (E65-3) - A2A+ (E45-28) Below 1 Ω A2A- (E65-4) - A2A- (E45-27) Below 1 Ω
- Standard resistance (Check for short):
Tester Connection Specified Condition HA1A( E68-1) or HA1A (E45-6) - Body ground 10 kΩ or higher A1A+ (E68-3) or A1A+ (E45-18) - Body ground 10 kΩ or higher A1A- (E68-4) or A1A- (E45-17) - Body ground 10 kΩ or higher HA2A (E65-1) or HA2A (E45-4) - Body ground 10 kΩ or higher A2A+ (E65-3) or A2A+ (E45-28) - Body ground 10 kΩ or higher A2A- (E65-4) or A2A- (E45-27) - Body ground 10 kΩ or higher
Reconnect the ECM connector.
Reconnect the A/F sensor connector.
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| OK | |
| 12.CHECK AIR INDUCTION SYSTEM |
Check the air induction system for vacuum leakage.
- OK:
- No leakage from air induction system.
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| OK | |
| 13.CHECK FUEL PRESSURE |
Check the fuel pressure.
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| OK | |
| 14.INSPECT FUEL INJECTOR ASSEMBLY |
Check the injector injection (whether fuel volume is high or low, and whether injection pattern is poor).
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| OK | |
| 15.REPLACE AIR FUEL RATIO SENSOR |
| NEXT | |
| 16.PERFORM CONFIRMATION DRIVING PATTERN |
| NEXT | |
| 17.CHECK WHETHER DTC OUTPUT RECURS (DTC P2195, P2196, P2197 OR P2198) |
Read DTCs using the intelligent tester.
Enter the following menus: Power train / Engine / DTC.
Result: Display (DTC Output) Proceed to No output A P2195, P2196, P2197 or P2198 B
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| A | |
| 18.CONFIRM WHETHER VEHICLE HAS RUN OUT OF FUEL IN PAST |
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| YES | ||
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